Kubota U20-3 Workshop Manual Download Page 322

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U20-3, U25-3 WSM

Hydraulic system (Service section)

-S-7

d. Motor

As listed above, there are various problems and their possible causes. The majority of troubles are,

however, caused by the entry of dust. Be very attentive not to allow any dust into the system.

Problem

Cause

Correction

Motor failure

to run

No pressure rise or no oil flow.

Check the entire hydraulic circuit including the valves and pumps.

Oil viscosity inappropriate.

Ensure the specified viscosity ranges.

Dust, degraded hydraulic oil, cavitation,
internal parts seized due to excessive radial
load, unusual contact, bearing damaged.

Run the motor alone and get it under a pressure of 30 kgf/cm

(2.9

MPa) or so. If it fails to run, then some internal parts might be seized
or damaged. Disassemble the motor and replace damaged parts.

Rpm not as

designed

Incoming flowrate too low.

Check the pump discharge rate, the motor rpm, and the valves for oil
leak.

Low viscosity and internal leak for oil
temperature or other reason.

Ensure the specified viscosity ranges.

Internal parts worn out.

Replace worn-out parts.

Wrong

turning

direction

Wrong pipe connections.

Reverse the pipe connections.

Poor valve timing due to wrong
disassembling/reassembling procedures.

Disassemble and reassemble again for good valve timing.

Oil leak

Oil seal scratched or worn.

Replace the oil seal. Repair or replace if the shaft seal contact
surface is scratched or worn.

Loose bolt or plug, resulting in oil leak (at
joints) from O-ring.

Tighten the bolt and plug to their specified torques. See also if the O-
ring is damaged. Replace the O-ring as required.

O-ring scratched or damaged.

Replace the O-ring.

Dust or dent on the O-ring contact face.

Check for hit marks, burr, etc. Correct the surface with #600 or so
sandpaper. Replace the O-ring. Clean up and reassemble.

Cracked port, damaged screw.
Inappropriate joint.

Replace the housing. Use an appropriate joint and tighten it to the
specified torque.

Unusual

noise

Shaft poorly fitted.

Center the shaft exactly.

Air left in the circuit or motor.

Let out the air completely. Fill the motor with oil and keep it running
under no load until there is no air bubbles in the tank.

Pump's cavitation.

Unclog the suction filter.

Air mixed in the suction pipe line.

Apply oil or grease to each connection and carefully listen to the noise
there. If the noise is less, retighten the joint there.

Unusual

temperature

rise

Cooler in trouble.

Repair the cooler.

Motor seized.

Repair or replacement

Summary of Contents for U20-3

Page 1: ...WORKSHOP MANUAL KUBOTA EXCAVATOR U20 3 Code No 97899 60740 U25 3 ...

Page 2: ......

Page 3: ... 1 Service Section II S 1 III Engine 05 M Series Engine III 1 Mechanism Section III M 1 Service Section III S 1 IVHydraulic System Mechanism Section IV M 1 Service Section IV S 1 V Electrical System Mechanism Section V M 1 Service Section V S 1 CONTENTS ...

Page 4: ......

Page 5: ... PROCESS AND CRITICAL FUNCTIONAL PROCESS I 5 a Essential Adhesives I 5 b Important Safety Process I 5 c Important Critical Functional Process I 5 D IMPORTANT INSPECTION ITEMS AFTER REASSEMBLING I 5 E SERVICING FUNDAMENTALS I 6 a Items for Servicing I 6 b O ring Oil seal Circlip and Roll Pin I 8 c Piping I 10 d Machine Quality Specifications I 15 F Maintenance intervals I 23 a Maintenance intervals...

Page 6: ......

Page 7: ...ntification marks If trouble should occur during use or if servicing is necessary contact the dealer who handles the machine At that time please inform the machine model and engine type and serial numbers 1 Machine serial number 2 Engine serial number ...

Page 8: ...re appropriate space needed for disassembly to the job 2 Secure a clean safe place for arranging disassembled parts 3 Store volatile substances gasoline light oil thinner oily articles etc in appropriate containers at selected locations to prevent fire hazards b Safety measures during work 1 Protectors 1 Wear goggles when using chisels for chipping 2 Use appropriate protectors during welding 3 Wea...

Page 9: ...nd parts storage racks as required d Precautions for disassembly and reassembly 1 Disassembly 1 Follow the specified disassembly procedures 2 Make alignment marks to insure correct reassembly 3 Arrange disassembled parts in an orderly way and attach identification tags or put marks if needed 2 Reassembly 1 Clean all parts before assembly Repair any scratches or dents Take special precautions again...

Page 10: ...1 Setting up the travel wheel motor tightening torque 2 Reassembling the rotary joints joint direction and shaft set up 3 Installing the swivel base bearing and the swivel motor tightening torque 4 Fitting the pump couplings tightening torque D IMPORTANT INSPECTION ITEMS AFTER REASSEMBLING a Operate the Machine and check for Unusual Noise and Vibrations b Make Sure the Safety decals and Wireharnes...

Page 11: ...acuum pump plugs oil pans waste cloth and the like to prevent oil from running out or splashing Wipe out leaking oil completely first and then add oil as required Protect the openings with plugs covers or the like to keep off foreign matters Most of hydraulic system troubles are caused by the entry of foreign matters Before reassembling clean up the parts and components and apply hydraulic oil on ...

Page 12: ...nut to its specified torque 2 Then loosen the nut by about 45 to fit the seat of the joint to the connection 5 The quantities of oil fuel water and others except for the oil to be filled in the track rollers and idlers are listed just as reference Fill up the fluid up to the specified center level of a level gauge if it is provided 6 Security support the machine with a jack and a supporting jig wh...

Page 13: ...nto its groove without twist With your fingertip push the ring gently and evenly into the final position Otherwise the ring would easily get twisted in contact with the inner edge of the groove 3 Floating seal Be sure to wipe oil off the O ring and the O ring contact surface Note however that oil must be applied thinly over those of the wheel motor In fitting the O ring into the floating seal be c...

Page 14: ...uitable tool and tap it evenly without allowing any tilt Press fit the oil seal deep down to the bottom of the oil seal fitting boss 5 Mounting the circlip Place the circlip with its sharp edge facing outward in the locking direction Fit the circlip securely in the groove For the hole circlip in particular install and turn it slightly to make sure it fits well 6 Tapping the roll pin spring pin Pla...

Page 15: ...ose s taper for dust deposits and scratches When the pipe socket has been tightened up wipe the joint clean Apply the maximum operating pressure 2 or 3 times to make sure there is no oil leak 2 Hydraulic hose Check the hydraulic hose for too tight a connect or twist Excessively tight contact Let s suppose that a hose is in contact with another hose or other part If the hose is pulled away by a for...

Page 16: ...7 1 14 0 15 0 147 1 166 7 15 0 17 0 41 mm Thread size piping screw Tightening torque N m kgf m Spanner size reference Remarks Steel pipe OD R tapered thread G straight thread 1 8 19 6 29 4 N m 2 0 3 0 kgf m 17 mm When in steel pipe is in use 8 mm 1 4 36 3 44 1 3 7 4 5 W O ring Joint Torque 58 8 78 5 6 8 19 mm 12 mm 3 8 39 2 49 0 4 0 5 0 W O ring Joint Torque 78 5 98 1 8 10 23 mm 15 mm 1 2 49 0 68 ...

Page 17: ...8311 72820 7 Ø13 20 RB101 63630 3 4 4 4 35 45 8 Ø40 55 RC411 63180 4 9 5 9 50 60 9 Ø77 95 69284 63170 10 Ø50 60 RC401 63190 11 Ø32 44 RD411 63820 Steel pipe size O D I D Thickness Tightening torque N m kgf m Spanner size reference Remarks 8 6 1 mm 29 4 39 2 3 0 4 0 17 mm When sleeve nut is in use 10 7 1 5 mm 39 2 44 1 4 0 4 5 19 mm 12 9 1 5 mm 53 9 63 7 5 5 6 5 21 mm 16 12 2 mm 88 3 98 1 9 0 10 0 ...

Page 18: ...m 77 5 90 2 N m 7 90 9 20 kgf m 103 0 117 7 N m 10 50 12 00 kgf m M14 107 9 125 5 N m 11 00 12 80 kgf m 123 6 147 1 N m 12 60 15 0 kgf m 166 7 196 1 N m 17 00 20 00 kgf m M16 166 7 191 2 N m 17 00 19 50 kgf m 196 1 225 6 N m 20 00 23 00 kgf m 259 9 304 0 N m 26 50 31 00 kgf m M18 245 2 284 4 N m 25 00 29 0 kgf m 274 6 318 7 N m 28 00 32 50 kgf m 343 2 402 1 N m 35 00 41 00 kgf m M20 333 4 392 2 N ...

Page 19: ...and until the washer comes into contact Note Clean up the mating seal beforehand 2 Positioning Turn the elbow back to its set position Note Do not make any more than one turn back 3 Fixing Tighten up the lock nut with a wrench Lock nut tightening torque Size N m kgf m G1 4 25 30 2 5 3 0 G3 8 49 54 5 0 5 5 G1 2 59 64 6 0 6 5 G1 8 15 16 5 1 5 1 7 ...

Page 20: ... 0 9 2 R rpm 8 9 0 9 9 5 0 9 3 Travel speed Rubber F1 km h 2 2 0 2 2 5 0 2 4 Rubber F2 km h 4 2 0 4 4 5 0 4 5 Iron F1 km h 2 1 0 2 2 4 0 2 6 Iron F2 km h 4 0 0 4 4 4 0 4 7 Gradeability deg 30 30 4 1 Rear end min turning radius mm 720 14 765 15 2 Swivel frame rear ground clearance mm 490 10 524 10 3 Tambler center distance mm 1474 44 1561 47 4 Crawler total length mm 1851 56 1996 60 5 Crawler total...

Page 21: ... 910 27 1060 32 19 Mini turning radius Conopy mm 1760 53 1798 54 20 Cabin mm 1945 58 1945 58 21 Mini turning radius Left swing Conopy mm 1330 40 1430 43 22 Cabin mm 1520 46 1515 45 6 1 Dozer Width mm 1400 5 1500 5 2 Height mm 292 10 292 10 3 Max lift above GL mm 318 50 354 50 4 Max below GL mm 440 50 315 50 Q2 Main Specs JIS A8404 1 1 Bucket tooth slaggish mm 73 0 73 0 F 30 kgf 2 Tilt amount of fr...

Page 22: ...lifting capacity kgf 450 459 Front end Arm extend bucket crowd at tooth Bucket tooth root Machine stance to JIS bucket tooth root Cutting edge down force at ground level kN 4 4 4 5 2 Arm digging force kgf 1286 1388 kN 12 6 13 6 3 Bucket digging force kgf 1786 2092 kN 17 5 20 5 2 1 Boom speed Canopy up sec 2 8 0 3 2 4 0 3 Ground to max 2 up sec 4 4 0 3 3 2 0 3 Min to max 3 down sec 2 9 0 3 2 7 0 3 ...

Page 23: ... 42 1510 45 6 Cabin mm 1215 36 1360 41 7 Bucket wrist angle degree 184 3 184 3 Q6 Swivel swing performance 1 1 Swivel torque L kgf m 388 429 Arm extend show Quick kN m 3 8 4 2 2 R kgf m 388 429 kN m 3 8 4 2 2 1 Swivel capable angle L deg 22 20 Bucket heaped 2 R deg 22 20 3 1 Swivel block performance L deg 5 5 Engine stop 2 R deg 5 5 3 L deg 30 30 Engine idle rpm 4 R deg 30 30 4 1 Swivel start up s...

Page 24: ...et crowd bucket heaped 10 min 2 95 5 C mm 20 20 3 Arm 50 5 C mm 11 11 4 Bucket 50 5 C mm 10 10 5 Dozer 50 5 C mm 20 20 3 1 Boom cushioning performance 30 C 86 F sec 3 3 Arm extended Bucket crowd Bucket empty Engine Max rpm 2 50 C 122 F sec 0 4 1 3 0 4 1 3 3 80 C 176 F sec 0 3 0 3 Q8 Lever operating force stroke 1 1 Boom lever up kgf 1 47 0 5 1 50 0 5 N 14 5 15 5 2 down kgf 1 47 0 5 1 50 0 5 N 14 5...

Page 25: ...ravel lever L Forward kgf 1 27 0 5 1 27 0 5 N 12 0 5 12 0 5 12 Back kgf 1 27 0 5 1 27 0 5 N 12 0 5 12 0 5 13 R Forward kgf 1 27 0 5 1 27 0 5 N 12 0 5 12 0 5 14 Back kgf 1 27 0 5 1 27 0 5 N 12 0 5 12 0 5 15 Accelerator lever up kgf 7 1 7 1 N 69 10 69 10 16 down kgf 7 1 7 1 N 69 10 69 10 17 Swing pedal R kgf 5 1 5 1 N 49 10 49 10 18 L kgf 5 1 5 1 N 49 10 49 10 19 Safety lock lever R up kgf 0 47 0 2 ...

Page 26: ...10 7 Swivel lever stroke L mm 72 10 72 10 8 R mm 72 10 72 10 9 Dozer lever stroke up mm 60 10 60 10 10 down mm 60 10 60 10 11 Travel lever stroke L Forward mm 70 10 70 10 12 Back mm 70 10 70 10 13 R Forward mm 70 10 70 10 14 Back mm 70 10 70 10 Q9 Stability 1 1 Standard arm Dynamic operation load limit Bucket load to 10 degrees tipping Side dozer up kgf Arm extend bucket crowd oil temp 50 5 C 122 ...

Page 27: ... Side kgf 223 293 N 2189 2877 6 Front kgf 288 372 N 2833 3654 Q10 Comfortability 1 1 Noise level At operator s ear LPA Canopy db A 80 81 2 Cab db A 80 81 Cab door close 3 Noise source LWA 7m db A 65 4 65 4 Power of noise level db A 92 94 92 94 No Specifications Items Unit U20 3 U25 3 Remarks ...

Page 28: ...fuel filter daily Tracks and chassis clean visual inspection and check tension weekly 50 hrs Grease swivel gear 50 hrs Check clean air filter 1 50 hrs Check nuts and bolts 100 hrs Grease swivel gear bearing 200 hrs Check battery electrolyte level 500 hrs Drain water in fuel tank 500 hrs Service Elapsed Operating Hours 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000 ...

Page 29: ...than at normal excavating work 2 Use only the recommended oils mentioned in the operator s manual when changing or fill oil 3 When filling up oil never mix oils of different makes 2 Changing the return filter and oil 1 The filter must be changed more often because of contamination resulting from the frequent assembly and disassembly of the hoses 2 Use the correct replacement filter 3 Oil change ac...

Page 30: ...ings and sealing for new ones at the same time Check the fuel and hydraulic hoses too at the following periodic inspections List of important parts Note The marked hydraulic hoses are Kubota s genuine ultra wear resistant hoses Be sure to use these parts Inspection intervals Inspection item Daily inspection Fuel and hydraulic hose connections as well as crimped parts for oil leak Monthly inspectio...

Page 31: ... Machine body Mechanism section A Specifications II M 2 a Specifications II M 2 b Main dimensions II M 3 B Components interchangeability II M 4 a Bucket II M 4 C Machine structure II M 5 a Control linkage II M 5 b Engine mount II M 9 c Undercarriage II M 11 ...

Page 32: ......

Page 33: ...side cutter mm 450 500 Engine Type water cooled 4 cycle Diesel 3 cylinder 3 cylinder Model name KUBOTA D1105 EBH 10 KUBOTA D1105 EBH 11 Total displacement cm3 1123 1123 Output ISO 9249 kW 14 0 15 5 Rated speed rpm 2200 2400 Performance Swing speed rpm 9 6 9 8 Travel speed km h 2 2 4 2 2 5 4 5 Ground pressure kPa kgf cm2 25 1 0 26 26 6 0 27 22 9 0 23 24 0 0 24 Climbing angle deg 36 20 36 20 Dozer w...

Page 34: ...400 1300 1500 710 760 1300 1400 1300 1500 3970 3650 2610 2320 2320 1900 1780 1940 2380 2360 320 330 440 280 2920 930 3850 4030 4140 800 U20 3 CANOPY 590 620 1500 760 1300 1500 4400 4160 3020 2790 2550 2300 1790 1940 2420 2400 360 320 3110 990 4100 4400 4510 800 U25 3 CANOPY Cabin type models Track width changes models mm ...

Page 35: ...ess local bucket in your place Still bucket size and weight should be considered for safety stability and performance U20 U20 3 U25 3 Bucket a Bush inner dia 30 30 b Arm boss inner dia 38 38 45 c Bucket boss inner dia 30 30 d Link 38 45 e 132 139 8 f 110 110 g 166 154 h 190 178 i 217 194 j pin dia 30 30 0 13 0 10 0 13 0 10 0 05 0 0 05 0 0 05 0 0 10 0 05 0 10 0 05 0 025 0 0 025 0 0 5 1 0 0 1 0 0 0 ...

Page 36: ...ection II M 5 C Machine structure a Control linkage 1 Traveling lever 3 2 1 5 6 4 No 1 2 3 4 5 6 PART NAME Traveling lever left Traveling lever right Travel left section Travel right section Lock position Release position Traveling Lever Lock ...

Page 37: ... 3 U25 3 WSM Machine body Mechanism section II M 6 2 Dozer lever 3 Accelerator lever 3 1 2 No 1 2 3 PART NAME Dozer lever Dozer cable Dozer section 1 2 No 1 2 PART NAME Accelarator lever Accelarator cable ...

Page 38: ...U20 3 U25 3 WSM Machine body Mechanism section II M 7 4 Swing pedal 5 Service port pedal 1 2 No 1 2 PART NAME Swing Pedal Swing Section 2 No 1 2 PART NAME Service port Pedal Service port section 1 ...

Page 39: ...U20 3 U25 3 WSM Machine body Mechanism section II M 8 6 Retractable track lever 3 2 1 No 1 2 3 PART NAME Retractable track lever Retractable track cable Track section ...

Page 40: ... 3 WSM Machine body Mechanism section II M 9 b Engine mount No 1 2 3 4 5 6 7 8 9 10 PART NAME Bracket 1 Engine Bracket 2 Engine Bolt Rubber cussionLock Bolt Washer plain Washer spring Nut Bolt Spring plate 10 9 ...

Page 41: ...U20 3 U25 3 WSM Machine body Mechanism section II M 10 4 2 1 3 5 6 7 No 1 2 3 4 5 6 7 PART NAME Unit radiator Bracket radiator Hose inlet Tank reserve Assy airclearner Muffler Pipe exast ...

Page 42: ...ism section II M 11 c Undercarriage 1 Tension spring 2 Upper roller and Track roller No 1 2 3 4 PART NAME Assy idler Assy spring Bolt Assy cylinder No 1 2 3 4 5 6 PART NAME Assy track roller Bolt Assy upper roller Bolt Nut Washer spring ...

Page 43: ...Plate 4 090 01133 61220 Bolt 8 095 04013 60120 Washer plain 8 100 RB411 21820 Guide crawler 4 110 01133 61020 Bolt 12 200 RB411 22310 Crawler rubber 2 210 RB411 22100 Assy crawler 2 No PART No PART NAME Q ty Rubber crawler Steel crawler 070 06331 35012 Plug 8 080 RB511 21812 Plate 4 090 01133 61220 Bolt 8 095 04013 60120 Washer plain 8 100 RB511 21820 Guide crawler 4 110 01133 61220 Bolt 12 200 RB...

Page 44: ... required not required No PART No PART NAME Q ty Rubber crawler Steel crawler 140 06331 35012 Plug 8 150 RB411 21812 Plate 4 160 01133 61220 Bolt 8 170 04013 60120 Washer plain 8 180 RB411 21820 Guide crawler 4 190 01133 61020 Bolt 12 200 RB411 22310 Crawler rubber 2 210 RB411 22100 Assy crawler 2 ...

Page 45: ...frame right 4 Bolt stopper 5 Hock towing 6 Blade left 7 Blade center 8 Blade right 9 Pin 10 Apply grease all over the hatched inner surfaces Do the same for the right inner surfaces 8 4 3 2 5 10 10 1 7 9 6 Bring in slight contact without looseness Lock the nut Now make sure the extension blade lock pin can be smoothly pulled in and out Bolt Nut ...

Page 46: ...cord strength 5690 N Piece 9320 N Piece Steel cord number 15 2 21 2 Core steel pitch 47 53 Core steel No 84 80 Crawler width 250mm 300mm No PART NAME 1 Rubber 2 Core steel 3 Flexing center 4 Core steel length No PART NAME 1 Rubber 2 Core steel 3 Fiexing center 4 Core steel length 5 Track roller passage groove 9 mm deep at one joint only 21 Groove 10 mm deep at other joints ...

Page 47: ...U20 3 U25 3 WSM Machine body Mechanism section II M 16 6 Steel crawler U20 3 No 1 Link 2 Bush 3 Pin ...

Page 48: ...U20 3 U25 3 WSM Machine body Mechanism section II M 17 U25 3 No 1 Hole 2 shaft ...

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Page 50: ......

Page 51: ... U25 3 WSM Machine body Service section II S 2 A Specifications a Machine weight STD Arm unit U20 3 U25 3 Canopy Rubber crawler kg 2030 2460 Iron crawler kg Cabin Rubber crawler kg 2120 2540 Iron crawler kg ...

Page 52: ...y mm 2298 2526 cabin mm 2298 2526 Max digging height canopy mm 3965 4353 cabin mm 3655 4125 Max digging radius canopy mm 4136 4501 cabin mm 4136 4501 Max dumping height canopy mm 2610 2994 cabin mm 2320 2775 Swing angle left right deg 73 55 73 55 Travel speed Low speed km h 2 2 2 5 High speed km h 4 2 4 5 Swing speed rpm 8 9 9 2 Max traction force Low speed kN kgf 17 2 1754 22 5 2294 High speed kN...

Page 53: ...13 1 34 1 34 15 15 1 5 1 5 Crowd Dump Swivel Stroke mm 72 72 72 72 Right Left Force N kgf 13 13 1 34 1 34 15 15 1 5 1 5 Right Left Travel Stroke mm 70 70 70 70 F R Force N kgf 12 12 1 27 1 27 12 12 1 27 1 27 F R Dozer Stroke mm 60 60 60 60 Up Down Force N kgf 20 20 2 0 2 0 20 20 2 0 2 0 Up Down Acceleration Force N kgf 44 39 4 5 4 0 44 39 4 5 4 0 Up Down Swing pedal Force N kgf 44 44 4 5 4 5 44 44...

Page 54: ...30 118 30 118 5 Pin diameter length mm 30 83 5 30 83 5 6 Pin diameter length mm 60 104 60 104 7 Pin diameter length mm 60 137 60 137 8 Pin diameter length mm 40 177 40 177 9 Pin diameter length mm 40 145 40 163 10 Pin diameter length mm 40 199 40 199 11 Pin diameter length mm 40 145 40 163 12 Pin diameter length mm 40 104 40 104 13 Pin diameter length mm 30 170 30 170 14 Pin diameter length mm 30 ...

Page 55: ...A JAPAN BUCKET No Unit U20 3 U25 3 Remarks 1 mm 400 450 2 mm 450 500 3 mm 76 3 9 5 76 3 9 5 4 mm 154 154 5 mm 110 110 6 mm 12 12 7 mm 22 22 8 mm 55 55 9 mm 49 49 10 mm 65 65 11 mm 30 30 12 mm 30 30 13 mm 563 5 563 5 14 mm 478 478 15 mm 78 5 78 5 16 mm 145 7 145 7 17 mm 139 139 18 mm 14 5 14 5 ...

Page 56: ...nt dimensions NOTE KUBOTA JAPAN BUCKET STANDARD ARM No Unit U20 3 U25 3 Remarks A mm 59 8 59 8 B mm M12 1 25 M12 1 25 C mm 52 52 D mm 60 60 E mm 30 30 F mm 5 5 G mm 795 905 H mm 10 10 I mm 250 259 J mm 225 5 225 5 K mm 157 157 L mm 1015 1076 5 M mm 250 250 N mm 255 255 O mm 145 145 ...

Page 57: ... Iron mm 84 80 FCD450T Rubber crawler center round length mm 3948 4240 Core Iron pitch mm 47 53 Rubber thickness mm 51 59 5 Unit U20 3 U25 3 Remarks Crawler assy code No RB411 2210 0 RC308 2210 0 Crawler width mm 250 300 1 4 links length A B mm 360 406 2 Height A B mm 56 68 3 Bushing O D A B mm 22 28 4 Bushing I D A B mm 14 17 5 Master pin O D A B mm 14 17 6 Grouser Height A B mm 16 5 16 5 7 Crawl...

Page 58: ...D Upper roller diameter A B mm 76 3 76 3 E Sliding plate thickness A B mm 22 11 22 11 Unit U20 3 U25 3 Remarks 1 Idler O D A B mm 238 230 272 264 2 Guide width A B mm 24 20 30 26 3 Idler width A B mm 88 84 113 109 4 Sprocket wheel O D A B mm 316 308 356 348 5 Sprocket wheel width A B mm 23 19 30 26 A B C D E A New machine reference value B Allowable limit 4 5 3 1 2 A New machine reference value B ...

Page 59: ...Pin diameter length mm 40 125 40 125 B Pin diameter length mm 45 95 45 95 C Pin diameter length mm 45 95 45 95 D Dozer width mm 1400 1500 E Dozer height mm 292 292 F Dozer length mm 934 966 G Dozer tip plate height thickness mm 65 12 65 12 H Length between dozer arms mm 420 420 C B A G F D E H ...

Page 60: ...left Weight right Weight rear 220 380 Rubber crawler 86 125 Iron crawler 88 168 Arch 36 36 Engine 89 89 Dry weight Hydraulic tank 21 21 With filter Fuel tank 4 4 Swivel bearing 24 24 Buttery 16 16 Track roller 5 5 Upper roller 3 3 Rops Fops canopy Rops Fops cabin Pump 17 17 Traveling motor 25 24 Swivel motor 23 23 Control valve 31 29 Without adaptor Boom cylinder 201 261 Canopy Cabin Arm cylinder ...

Page 61: ... 31 31 Kubota LLC N 50F 50 Reserve tank L 0 6 0 6 Engine Crank case L 3 8 3 8 SAE10W30 CD Hydraulic oil Full L 37 37 ISO 46 Hydraulic oil Tank L 22 5 22 5 ISO 46 Wheel motor L 0 33 0 33 SAE90 API GL 4 Track roller CC 50 80 SAE30 CD Upper roller CC 60 60 SAE30 CD Front idler CC 35 75 SAE30 CD Fuel tank L 27 5 27 5 ...

Page 62: ...U20 3 U25 3 WSM Machine body Service section II S 13 B Front attachment a Parts designation ...

Page 63: ...etainer No PART NAME No PART NAME No PART NAME 010 Boom 085 Shim 170 Shim 020 Pin 090 Bolt 180 Shim 030 Shim 100 Nut Lock 190 Bolt 035 Shim 110 Pin 200 Nut Lock 040 Bolt 120 Nipple Grease 210 Pin 050 Pin 130 Shim 220 Nipple Grease 060 Pin 140 Bolt 230 Shim 070 Nipple Grease 150 Nut lock 240 Bolt 080 Shim 160 Pin 250 Nut Lock No PART NAME No PART NAME 010 Cover Cylinder 030 Washer Plain 020 Bolt 04...

Page 64: ...00 Link Bucket 180 Nipple Grease 030 Bolt 110 Link Bucket 190 Shim 040 Washer 120 Pin 200 Spacer 050 Assy link Bucket 130 Nipple Grease 210 Washer Plain 060 Bush 140 Shim 220 Bolt 070 Bush 150 Bolt 230 O ring 080 Collar 160 Washer 240 Cap No PART NAME No PART NAME No PART NAME 010 Blade 040 Bolt 070 Bolt 020 Nipple Grease 050 Nut Lock 080 Nut Lock 030 Pin 060 Pin ...

Page 65: ...g the pins be careful not to damage the dust seals Removing the bucket 1 Place the bucket just on a flat level ground 2 Stop the engine and let out pressure from the hydraulic system 3 Detach the O ring from the groove and draw out the pins A and B Move the O ring Bucket boss Fitting the bucket 1 Place the O ring on the boss of the bucket 2 Align the arm with the hole A put the shims at both ends ...

Page 66: ...les of the point and adapter and knock in the rubber plug together with the lock pin until the top surface of the pin is flush with the top surface of the adapter It is recommended to replace the rubber plug and lock pin when replacing the point Replacing the side cutter 1 Using a box wrench and an adjustable wrench remove the side cutter lock bolts 2 Fit new side cutters Temporarily tighten the b...

Page 67: ...ffect is adversely affected which may get the pins worn out earlier Installation of thrust collar on the swing bracket No 1 Bush 2 Dust seal 3 Enlarged view of dust seal 4 Toward the Bushing 5 Outside 1 Install the thrust collar t3 5 with its grooved face downward on top of the swivel frame 2 Select and install a 0 5 or 1 0mm 0 02 0 04 thick shim to have the clearance smaller than 0 5 mm No 1 Thru...

Page 68: ...in RC411 6694 Shim 0 5 65 41 RC411 6695 Shim 1 0 65 41 Use selectively 2 Arm assembly Bucket cylinder RC411 6694 Shim 0 5 65 41 RC411 6695 Shim 1 0 65 41 Use selectively 1 Swing bracket Swing cylinder 68721 6697 Shim 0 5 60 31 68721 6633 Shim 1 0 60 31 68721 6634 Shim 1 6 60 31 Use selectively 5 The marked parts are different between U20 3EU and U25 3EU 1 11 5 10 6 9 8 7 4 2 3 Boom assembly Boom c...

Page 69: ... 14 Arm assembly Bucket link double support Arm side Bucket link 2 3 Iron Grease nipple A type Bolt Not Bush Link Bucket Link Bucket Collar Dust seal Pin 13 Bucket link single support Bucket CYL side Bucket link 1 2 3 Grease nipple A type Bolt Not Pin Bush Align with the outer face Abolished Link Bucket Link Bucket 4 15 Bucket Bucket link single support Bucket side Bucket link Dust seal Bush Iron ...

Page 70: ...ting hours whichever comes earlier 2 Front hose assembly U25 3 Pipe hydraulic bucket Bolt Bolt Over 86 Pipe hydraulic SP right Pipe hydraulic SP left Pipe hydraulic Arm Wider side inward A View from the boom end SP pipe Adaptor 7 Pipe joint SP Plug Valve assembly stop Cover cylinder Unit mm Cap Cylinder cover Setup direction Keep the cock facing the bucket cylinder arm top RB519 6881 2 9 9 9 9 ...

Page 71: ... clamp Clamp 1 front Bucket rod red Bucket bottom white Left side of machine Right side of machine SP high violet SP low brown Cushion hose R B 4 1 9 6 6 9 1 Arm bottom blue Arm rod black Plug Stay harness clamp Bolt 1 1 7 8 3 4 5 a a Service port b Arm c To be out of contact b 6 2 2 5 6 7 3 4 8 c No 1 2 3 4 5 6 7 8 Location Boom bottom Boom rod Arm rod Arm bottom Bucket rod Bucket bottom S P Low ...

Page 72: ...vel levers 14 degrees 5 01175 61045 Locking the stopper bolt Bring the stay of the lever travel right left in contact Loosen the bolt by 90 degrees and lock it in this position Make sure the valve spool works all over its stroke 6 With the levers at the neutral positions orient this part vertically 7 Move down the lever lock travel against the spring force to unlock the travel mode 8 Adjust the ro...

Page 73: ...e body Service section II S 24 2 Check items after setup Make sure the valve spool works all over the stroke Make sure the valve spool moves smoothly Lock the stopper bolt and nut tight enough Lever assembly lock travel 7 8 ...

Page 74: ...60 05525 51600 RB411 6533 04013 60080 05525 50800 Remarks M12 1 25 4T M10 1 25 9T M10 1 25 7T M10 1 25 4T M10 1 25 4T M10 1 25 4T M10 1 25 4T Q ty 1 1 2 1 1 1 2 2 4 4 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 Part name Lever assembly travel left Lever travel left Needle bearing Plastic cap Nut Pin travel Bolt Plain washer Bolt Nut Rod 10 305 Link ball 1 Spring washer Nut Nut Left threaded lock nut Link ba...

Page 75: ... 4 3 No Part No Part name Q ty Remarks 1 RG518 6611 Assy Cylinder TL 1 2 01123 60820 Bolt 4 3 RC418 6613 Pipe joint S G1 8 G1 4 1 4 04810 00080 O ring 1 5 RP821 6197 Pipe joint QL G1 4 8 4 1 6 RB419 6607 Bracket lock travel 1 7 01123 60820 Bolt 3 8 RB419 6610 RB419 6609 08511 01216 Lever assembly lock travel Lever lock travel Bushing 1 1 2 9 RC418 6608 Shaft lock travel 1 10 01123 60820 Bolt 1 11 ...

Page 76: ... the rotary shaft turns smoothly 6 Tightening torque of bolt 14 48 1 55 9N m 4 9 5 7kgf m 7 Parts list No Part No Part name Q ty Remarks 1 RB411 3539 Spring acceleration 1 2 RB411 3515 Cable acceleration 1 3 04013 60060 Plain washer 2 4 05511 51612 Split pin 2 No Part No Part name Q ty Remarks 8 RB411 3510 Lever assembly acceleration 1 RB411 3511 Lever acceleration 1 08511 01625 Bushing 1 9 41233 ...

Page 77: ...B411 5329 Δ Cable meter 3 36200 77611 Cord clamp assembly 2 4 RB411 3515 Δ Cable acceleration 5 Pass on top of the water hose 6 Clamp to the cover fan 7 Pass below the water hose 8 Grommet 9 Swivel frame guide member Minimum bending radius of cables To be over 150R Pass the cables along the shown routes without kink 6 1 2 3 4 8 9 7 5 ...

Page 78: ...2 4 3 5 9 8 No 1 Step 5 2 RB411 5329A Cable meter 3 RB411 3515 Δ Cable acceleration 4 Muffler bracket 5 36200 77611 Cord clamp assembly 2 6 Pass between the swivel frame partition and frame arch 7 Pass on top of the suction hose 8 Swivel frame guide member 9 Grommet Pass through the notch of the swivel frame ...

Page 79: ... least 20mm 3 Allowable cable bending radius To be over 150R 4 Check items after setup 1 Make sure the valve spool works all over the stroke 2 Make sure the valve spool moves smoothly 5 Parts list Dozer cable route Guide No Cover right top RB411 4476Δ Move the lever full stroke to see if the lever does not hit the cover right top No Part No Part name Q ty Remarks 1 56501 17531 Grip 1 2 RB411 6577 ...

Page 80: ...519 Part No 02116 50100 68011 3268 04512 60100 02118 60100 RB411 6534 04013 60080 05525 50800 69254 7828 52300 7517 52300 7519 02116 50100 04512 60100 02118 60100 68011 3268 RB411 9214 RB411 9213 08511 01615 RC418 9217 05122 51075 04011 50100 05511 50318 01133 61020 01135 61030 Part name Bracket assembly pedal Bracket swing pedal Bushing Pedal swing Plain washer Snap pin Lever assembly SP Lever SP...

Page 81: ...l stroke and release them Now make sure the pedal goes back smoothly to its neutral position 1 Assembling procedure 1 Adjusting the pedal Make sure the pedal stays horizontal at the center and swings equally right and left To and fro Service port Right and left Swing 2 Tightening torque of link ball lock nut 39 2 45 1N m 4 0 4 6kgf m 3 Link fitting dimensions Fit the link as shown at left 1 Port A...

Page 82: ...pply screw LOCTITE Three BondTB1401B CAUTION Allow no gap at the points A and B when the limit switch is activated 2 Apply instantaneous adhesive to the acceleration pedals rubber cover and attach it in place 3 Hook the tension spring to the unload lever left Make sure the end of the spring hook at the unload lever faces outward of the machine 4 Squeeze allowance of seat support rubber 1 2mm 5 App...

Page 83: ...ightening torque of filter suction 58 8 68 6N m 6 0 7 0kgf m 1 2 10 13 14 16 17 4 3 5 7 Fit the edge along the rounded line reference 6 11 12 8 9 15 No Part No Part name Q ty Remarks 1 RB411 6211 Hydraulic oil tank 1 2 06312 10010 Plug 1 3 RB411 6216 Support filter 1 4 RC101 6223 Gasket 1 5 02114 60080 Nut 1 M8 4T 6 RB411 6219 Filter assembly return 1 7 RB411 6215 Filter suction 1 8 06331 35016 Pl...

Page 84: ...allowance of fuel band out of the hydraulic oil tank 23 1mm reference CAUTION With the band in place make sure the fuel tank is tight in position 3 Parts list No Part No Part name Q ty Remarks 1 RB411 5111 Fuel tank 1 511 2 68701 51121 Cap assembly Fuel 1 3 35450 41061 Fuel filter assembly 1 4 RB411 5114 Sensor Fuel 1 5 RC101 51343 Gasket 1 6 03024 60512 Head screw with washer 5 M5 0 8 7 RB411 513...

Page 85: ...U20 3 U25 3 WSM Machine body Service section II S 36 2 Fuel hose MPORTANT Replace the fuel hose after 2 years or 4000 operating hours whichever comes earlier I 3 Fuel hose routes ...

Page 86: ...y Remarks 1 RB419 4831ΔCounter weight Cabin 1 U20 3 EU Cabin type RB411 4831Δin different color Blue No 24 RB519 4811ΔCounter weight 1 U25 3 EU Cabin Cabintype RB511 4811Δ in different color Blue No 24 2 90585 1199Δ Plug 2 3 RC411 4841Δ Bolt 2 M20 2 5 4 04512 60200 Plain washer 2 5 RP801 4812Δ Washer 2 6 RB411 4325Δ Stay 1 bonnet 1 7 01135 61020 Bolt 1 M10 1 25 7T Counterweight identification Type...

Page 87: ...U20 3 U25 3 WSM Machine body Service section II S 38 D Cab canopy installation a Installing the cabin or canopy 1 Installing the cabin 1 Nut Front crosswise Back crosswise Front in different color ...

Page 88: ... section II S 39 Tuck the front opening window in the ceiling to see if it can be tightly locked 2 Canopy installation Front of the machine 1 Tightening torque of canopy lock screw 1 Bolt 2 Spring washer 3 Plain washer Back of the machine ...

Page 89: ...t 2 9 RB419 4772Δ Cover 1 cabin 1 Red No 1 433 RB411 4772Δ in different color No Part No Part name Q ty Remarks 1 RB411 3821Δ Cover Support Seat heater 1 Cabin type 381 2 3F760 56052 Grille assembly airconditioner 2 3 RB411 4271Δ Bracket 1 heater 1 4 RB411 4272Δ Bracket 2 heater 1 5 RB411 4274Δ Bracket 3 heater 1 6 01133 61020 Bolt 5 M10 1 25 7T 7 34070 72411 Heater unit 1 450 8 01025 60614 Bolt 4...

Page 90: ...ter 700 1 2 RB419 4927Δ Hose defroster 400 1 3 RB419 4923Δ Cover duct 1 4 68768 4253Δ Grommet 3 1 5 01125 60816 Bolt 2 6 RB419 4921Δ Duct 1 defroster 1 7 RC418 4924Δ Grille defroster 1 8 01125 60816 Bolt 3 Wire harness heater conversion 2 Cord band Clamp the heater and harness 5 8 1 6 8 7 2 3 4 4 Defroster setup ...

Page 91: ... ty Remarks 1 RB419 4591Δ Cover left cabin 1 Blue No 24 RB411 4591Δ in different color 2 RB411 4117Δ sound absorber cover left 1 3 RB411 4127Δ sound absorber cover left2 1 4 RB411 4128Δ Sound absorber cover left3 1 No Part No Part name Q ty 5 RB419 4690Δ Cover right 1 6 RB411 4696Δ Sound absorber cover right 1 1 4 3 2 Sealing rubber 3 Sealing rubber 7 Sealing rubber 5 Bonnet 1 left cabin Red No 1 ...

Page 92: ...nstall the seat belt for both the cabin and canopy types 2 Do not install the right hand unload lever on both the cabin and canopy types 1 Tightening torque of seat belt assembly 48 1 55 9N m 4 9 5 7kgf m CAUTION a b c d a b c d Seat belt assembly 36330 8515Δ Bolt 01135 61020 Orientation of seat belt fixture Folded end downward ...

Page 93: ...cylinder for cab type M2C marking M4C marking Cabin type Bushing Bushing Bushing Bushing Hydraulic cylinder assembly boom Rad No 1 Cabin type Hydraulic cylinder assembly boom Rad No 1 Cylinder identification Cabin Cabin Identified by markings in different color ...

Page 94: ...ne c Ball greasing port Match with the swivel frame holes d Ball inserting port Outer ring soft zone e S marking Inner ring soft zone f Swivel frame side g Track frame side h Pay attention to the plain spring direction U 20 3 No Part No Part name Q ty Remarks 1 RB411 1911Δ Bearing swivel 1 2 01176 61240 Bolt 17 M12 1 25 9T 3 35340 2737Δ Plain spring 17 4 01176 61240 Bolt 20 M12 1 25 9T 5 35340 273...

Page 95: ... 2 If the cylinder has been detached check the rod rod seal O ring side for grease leak 3 If the nipple has been detached check the tube and nipple seat for scratches and dust deposits 4 In detaching the nipple keep in mind that the nipple may pop out because of the inner pressure of the cylinder No Part No Part name Q ty Remarks 1 RB411 2130Δ Idler assembly 2 U 20 3 RB511 2130Δ Idler assembly 2 U...

Page 96: ...t length of spring 174 3 0 5m Make the setting at the split pin position nearest to the above length No Part No Part name Q ty Remarks 10 15521 96023 Plug R1 8 1 9 68171 21391 WIre 1 8 05411 00663 Spring pin 1 φ6 L63 7 04811 50250 O ring 2 G25 6 RC301 21961 Bushing 2 5 RC301 21731 Seal floating 2 4 RB411 2134Δ Idler 1 3 RB411 2133Δ Shaft Idler 1 2 RB411 2132Δ Bracket 2 Idler 1 1 RB411 2131Δ Bracke...

Page 97: ...d and the track roller bracket 2 Tightening torque of roller assembly mounting bolt 103 117 7N m 10 5 12kgf m 3 Apply screw LOCTITE Three Bond 1305P to the internal threads Before doing this wipe out oil paint and other coating off the surface 3 Carrier roller 1 Tightening torque of carrier roller 103 117 7N m 10 5 12kgf m 2 Apply screw LOCTITE Loctite 271 to the carrier roller No Part No Part nam...

Page 98: ...ress fitted in place at one side A press is needed in order to detach and attach them 3 Apply the lube oil to the O ring of the shaft CAUTION In disconnecting the anti fall wire keep in mind that the wire may pop out 1 Check the O ring of the floating seal for dust and oily deposits Install the seal in place without twist and tilt 2 Apply the lube oil thinly over the seal sliding surface 3 Finally...

Page 99: ...meter as required If out of spec replace them with new ones 2 Put a bladed screwdriver at the cap side to disassemble the roller Replace the parts with new ones in this case No Part No Part name Q ty 1 RC411 2195Δ Carrier roller 1 2 RC411 2192Δ Shaft 1 3 RC601 2193Δ Oil seal 1 4 08101 06006 Ball bearing 2 5 Shaft circlip 1 6 RC601 2194Δ Plug 1 7 RC601 2196Δ Spacer 1 ...

Page 100: ... careful to keep the roller inside and incoming parts free from dust cuttings and other foreign matters 2 The lube oil to pour is Engine Oil Class SAE 30CD Its specified amount is 60cc CAUTION In disassembling and reassembling keep in mind that the shaft circlip may pop out ...

Page 101: ...further readjustment will be necessary Rotate the crawler after adjustment one to two times to check the tension Additionally following points are to be observed when adjusting rubber crawlers 1 If the crawler slackens more than 25mm readjust them 2 Check crawler tension 50 hours after initial use and readjust if necessary Check and adjust thereafter every 50 service hours Rubber crawler Iron craw...

Page 102: ...mm 164 159 169 Track frame center Blade size Stretchable width mm 1300 1295 1305 Blade size Retractable width mm 1500 1495 1505 Blade size Height mm 293 283 303 Blade upper limit mm 333 283 383 Blade lower limit mm 277 227 327 Blade approach angle 33 8 30 37 Dozer speed Top ground upper limit Sec 1 1 0 8 1 4 Dozer speed Top lower limit upper limit Sec 2 2 1 9 2 5 Dozer speed Top upper limit ground...

Page 103: ...L 1 25p 7T 48 1 55 9N m 4 9 5 7kgf m 170 04013 60120 Plain washer 8 Iron crawler 180 RB411 2182 0 Guide crawler 4 Iron crawler 190 01133 61020 Bolt 12 Iron crawler M10 20L 1 25p 7T 48 1 55 9N m 4 9 5 7kgf m While Bolt Bolt stopper 4 pcs Spring washer 4 pcs Discontinued as from the 7th unit in August production Frame track center discontinued as from Hirakata production lot Frame Frack right Frame ...

Page 104: ...en passing through a narrow flat place For other traveling digging bulldozing and breaking jobs be sure to keep the track width largest Otherwise the machine may turn over Change the track width using the track stretch lever Large track width Tilt the track stretch lever forward The track width will be large 1300mm 1500mm Small track width Pull the track stretch lever toward yourself The track wid...

Page 105: ... 7146 0 Pipe holder 1 140 RD411 7147 0 Bolt assembly 1 150 RB411 7327 0 Cylinder repair kit 1 160 68051 6743 0 U ring 1 170 RB411 7113 0 Wiper ring 1 180 04810 50550 O ring 1 Class1B hard G fixing Nominal dia 190 RB411 7174 0 Ring backup 1 200 04811 50600 O ring 1 Class1A Soft G fixing Nominal dia 210 68811 9368 0 Seal ring assembly 1 220 RB411 7176 0 Ring slide 2 230 RB411 7145 0 O ring 2 17 17 T...

Page 106: ...screw 1 Tightening torque 6 86N m M6 1p Two spots to be then caulked with punch 100 68493 6767 0 Steel ball 1 110 RB411 7165 0 Pipe assembly 1 Variable track not included 110 RB411 7193 0 Pipe assembly 1 Variable track φ13 8 t2 4mm 120 RB411 7144 0 Plug 1 Tightening torque 39 3N m M12 1 25p 130 RB411 7145 0 O ring 2 140 RB411 7146 0 Pipe holder 1 150 RD411 7147 0 Bolt assembly 1 160 06611 15010 Gr...

Page 107: ...e track Fixed track reference 1 R J Travel M Travel top RB411 6467Δ RB411 6323Δ Hydraulic travel 3 8 2 940 red G3 8 SQ2106 G3 8 Ultra wear resistant 637 2 R J Travel M Travel bottom RB411 6468Δ RB411 6375Δ Hydraulic travel 3 8 2 940 G3 8 SQ2106 G3 8 Ultra wear resistant 3 R J Travel M Bi speed RB411 6469Δ RB411 6372Δ Hydraulic bi speed 1 4 2 1050 G1 4 PF1704 G1 4 See below 4 R J Travel M drain top...

Page 108: ...ht forward Right B top F Left backward Left B bottom G Right backward Left A bottom H Drain Right left drain port top Dozer Left track Right track Track No Part No Part name Q ty Remarks 1 RB411 1443Δ Drive sprocket 2 111 2 01128 61025 Bolt 18 M10 1 5 9T 3 RB411 6129Δ Motor assembly wheel 2 Fujikoshi made 614 4 01128 61025 Bolt 16 M10 1 5 9T 5 RB411 6394Δ Straight pipe joint 4 A B 6 68728 76151 Ad...

Page 109: ... hose blade 1 4 2 090 RB411 6471 0 Joint blade hose 2 100 01133 61020 Bolt 2 M10 20L 1 25p 7T 48 1 55 9N m 4 9 5 7kgf m 110 RB411 6476 0 Hydraulic hose blade 1 4 2 Length 440mm G1 4 CR4 G1 4 120 RB411 6487 0 Hydraulic hose 1 4 1 Length 660mm G1 4 CR9 G1 4 130 RB411 6488 0 Hydraulic hose 1 4 1 Length 800mm G1 4 CR4 G1 4 Dwg No Part No Part name Q ty Interchange ability Remarks A 010 RB411 6376 0 Pi...

Page 110: ...00mm G1 4 CR4 G1 4 190 RB411 6441 0 Hydraulic hose 3 8 1 Length 440mm G3 8 CR4 G3 8 200 RB411 6442 0 Hydraulic hose 3 8 1 Length 380mm G3 8 CR4 G3 8 210 RB411 6445 0 Hydraulic hose 1 4 1 Length 970mm G1 4 CR9 G1 4 Dwg No Part No Part name Q ty Interchange ability Remarks A 010 RB411 6394 0 Straight pipe joint 3 3 50 2 020 04810 00140 O ring 2 Class 1B hard P fixing movable nominal dia14mm 030 6872...

Page 111: ... ability Remarks A 010 RB411 6113 0 Control valve assembly variable 1 Variable track 135 RB411 7012 0 Valve assembly width 1 Variable track 310 04810 00140 O ring 19 Variable track Maker Kayaba Industry Model KVSE 36 11 Weight About 34 kg Component parts 16 Poppet E Cap screw F Spring G Wiper H O ring I O ring ...

Page 112: ...Blade side a No Part No Part name Q ty Remarks 1 RB411 6240Δ Swivel joint assembly 1 623 2 01176 61440 Bolt 4 M14 1 5 9T 3 35358 27371 Plain spring 4 4 RB411 6376Δ Pipe joint L G 1 4 G 1 4 4 A B J K 5 69254 78491 Pipe joint L G 1 4 G 1 4 1 C 6 RP201 61812 Pipe joint L G 3 8 G 3 8 3 D F G 7 68311 64321 Straight pipe joint 1 E 8 RC411 63881 Pipe joint bushing G 3 4 1 H 9 RD401 63951 Elbow pipe joint...

Page 113: ...Dwg No Part No Part name Q ty Interchange ability Remarks A 010 RB411 6590 0 Lever assembly track stretching 1 020 08511 01615 Bushing 2 030 04011 60160 Flat washer 1 040 05525 51600 Snap pin 1 050 RB411 6512 0 Link assembly dozer 1 060 08511 01615 Bushing 2 070 04011 60160 Flat washer 1 080 05525 51600 Snap pin 1 090 RB411 6578 0 Cable track stretching 1 White ID marking 100 RB411 6535 0 Rod 95 1...

Page 114: ...nterweight 1 Canopy fixed track 010 RB411 4821 0 Counterweight variable 1 Canopy fixed track 010 RB411 4831 0 Counterweight cabin 1 Cabin 020 90585 1199 0 Plug 2 030 RC411 4841 0 Bolt 2 M10 1 25 7T 040 RP801 4812 0 Washer 2 050 04512 60200 Spring washer 2 Model Part No Dimension A U 20 3 Fixed track canopy type RB411 4811 Δ 70 Variable track canopy type RB411 4821 Δ 70 Fixed track variable track c...

Page 115: ...U20 3 U25 3 WSM Engine III 1 III Engine A 05 M Series Engine WSM III 2 a Engine Specifications for construction machinery III 4 b Dimensions III 8 ...

Page 116: ......

Page 117: ...ism and Servicing for each section Mechanism Information on the Features and New Mechanisms are described This information should be understood before proceeding with troubleshooting disassembling and servicing Servicing The heading General includes general precautions check and maintenance and special tools There are troubleshooting checking and adjusting disassembling and assembling and servicin...

Page 118: ...U20 3 U25 3 WSM Engine III 3 ...

Page 119: ...5 5 24 3 Dri weight kg 89 lbs 196 2 Valve clearance mm 0 145 0 185 in 0 0057 0 0073 Firing sequence 1 2 3 Compression pressure A B MPa 3 23 3 63 2 3 kgf cm2 33 37 23 psi 469 526 327 Fan belt Bando RPF2370 Fuel consumption ratio g kWh 286 g Psh 210 lbs Hph 0 47 Fuel consumption l h 4 6 5 0 gal h 1 22 1 32 Max speed without load rpm 2600 Speed with 2 pumps relief rpm 2200 Speed with idling rpm 1200 ...

Page 120: ...ump Nozzle type DN4PDN mini nozzle Injection pressure MPa 13 7 14 7 kgf cm2 140 150 psi 1991 2133 Dynomo 12V360W Manufacturer P N 1G070 6401Δ Regulator adjusting voltage V 12V14A Battery type 75D23RMF Nominal capacity of 5hrs rating Ah 52 Specific gravity of electrolite 1 26 Starter motor 12V1 0kW Manufacturer P N 19269 6301Δ Glow plug Ω 0 9 ...

Page 121: ...U20 3 U25 3 WSM Engine III 6 Performance curves Model D1105 EBH 10 ...

Page 122: ...U20 3 U25 3 WSM Engine III 7 Performance curves Model D1105 EBH 11 ...

Page 123: ...U20 3 U25 3 WSM Engine III 8 b Dimensions ...

Page 124: ......

Page 125: ... pressure switch III M 9 D Cooling system III M 10 1 General III M 10 2 Water pump III M 10 3 Thermostat III M 11 4 Radiator not included in the basic engine III M 11 5 Radiator cap III M 12 E Intake exhaust system III M 13 1 Air cleaner not included in the basic engine III M 13 2 Muffler not included in the basic engine III M 13 F Fuel system III M 14 1 General III M 14 2 Injection pump III M 14 ...

Page 126: ......

Page 127: ...U20 3 U25 3 WSM Engine Mechanism section III M 2 A Feature ...

Page 128: ...U20 3 U25 3 WSM Engine Mechanism section III M 3 B Engine body 1 Cylinder block 2 Cylinder head ...

Page 129: ...U20 3 U25 3 WSM Engine Mechanism section III M 4 3 Crankshaft 4 Piston and piston rings ...

Page 130: ...U20 3 U25 3 WSM Engine Mechanism section III M 5 5 Connecting rod 6 Rocker arm 7 Camshaft ...

Page 131: ...U20 3 U25 3 WSM Engine Mechanism section III M 6 8 Fuel camshaft 9 Flywheel ...

Page 132: ...U20 3 U25 3 WSM Engine Mechanism section III M 7 C Lubricating system 1 General ...

Page 133: ...U20 3 U25 3 WSM Engine Mechanism section III M 8 2 Oil pump 3 Relief valve ...

Page 134: ...U20 3 U25 3 WSM Engine Mechanism section III M 9 4 Oil filter cartridge 5 Oil pressure switch ...

Page 135: ...U20 3 U25 3 WSM Engine Mechanism section III M 10 D Cooling system 1 General 2 Water pump ...

Page 136: ...U20 3 U25 3 WSM Engine Mechanism section III M 11 3 Thermostat 4 Radiator not included in the basic engine ...

Page 137: ...U20 3 U25 3 WSM Engine Mechanism section III M 12 5 Radiator cap ...

Page 138: ...U20 3 U25 3 WSM Engine Mechanism section III M 13 E Intake exhaust system 1 Air cleaner not included in the basic engine 2 Muffler not included in the basic engine ...

Page 139: ...U20 3 U25 3 WSM Engine Mechanism section III M 14 F Fuel system 1 General 2 Injection pump ...

Page 140: ...U20 3 U25 3 WSM Engine Mechanism section III M 15 ...

Page 141: ...U20 3 U25 3 WSM Engine Mechanism section III M 16 ...

Page 142: ...U20 3 U25 3 WSM Engine Mechanism section III M 17 3 Injection nozzle 4 Fuel filter not included in the basic model ...

Page 143: ...U20 3 U25 3 WSM Engine Mechanism section III M 18 5 Governor ...

Page 144: ...U20 3 U25 3 WSM Engine Mechanism section III M 19 ...

Page 145: ...U20 3 U25 3 WSM Engine Mechanism section III M 20 6 Automatic advance timer not included in the basic model ...

Page 146: ...U20 3 U25 3 WSM Engine Mechanism section III M 21 ...

Page 147: ...U20 3 U25 3 WSM Engine Mechanism section III M 22 G Electrical system 1 Charging system ...

Page 148: ...U20 3 U25 3 WSM Engine Mechanism section III M 23 H Turbo charger system ...

Page 149: ...U20 3 U25 3 WSM Engine Mechanism section III M 24 ...

Page 150: ...U20 3 U25 3 WSM Engine Mechanism section III M 25 ...

Page 151: ...U20 3 U25 3 WSM Engine Mechanism section III M 26 ...

Page 152: ...U20 3 U25 3 WSM Engine Mechanism section III M 27 ...

Page 153: ...II S 41 3 Cylinder head and valves III S 42 4 Gear case III S 44 5 Piston and connecting rod III S 50 6 Flywheel and crankshaft III S 53 SERVICING III S 55 1 Cylinder head III S 55 2 Timing gear and camshaft III S 60 3 Piston and connecting rod III S 62 4 Crankshaft III S 65 5 Cylinder III S 71 D Lubricating system III S 73 CHECKING III S 73 SERVICING III S 73 1 Oil pump III S 73 E Cooling system ...

Page 154: ...CKING III S 83 1 Starter III S 83 2 Glow plug III S 84 DISASSEMBLING AND ASSEMBLING III S 84 1 Starter III S 84 2 Alternator III S 85 SERVICING III S 88 1 Starter III S 88 2 Alternator III S 90 H Turbo charger system III S 93 CHECKING III S 93 DISASSEMBLING AND ASSEMBLING III S 95 ...

Page 155: ...tite 271 2 Tightening torque of anti vibration rubber 77 5 90 2N m 7 9 9 2kgf m Apply screw loctite Loctite 271 3 Parts list 4 Tightening torque of engine mounting bolt 103 0 117 7N m 10 5 12 0kgf m Apply screw loctite Loctite 271 5 Parts list Engine rear side No Part name Q ty Remarks 1 Bracket 1 engine 1 2 Bracket 2 engine 1 3 Bolt 6 M10 1 25 7T 4 Anti vibration rubber 4 5 Bolt 4 M12 1 25 7T 6 P...

Page 156: ...ont attachment and blade on the floor 2 Remove the bonnet and the right side cover 3 Remove the drain plug from the bottom of the radiator to let out all cooling water For changing the cooling water refer to page A 31 4 Using a vacuum pump detach the oil cooler 5 Disconnect the two radiator hoses from the radiator Take out the radiator ...

Page 157: ...II S 5 Radiator assembly view 1 2 Reassembling the radiator 1 Clearance between radiator core fin and fan part A 60 67 mm Keep the fan stretching evenly out of the fan shroud 2 Clearance between fan and fan shroud part B Over 10 mm 1 10 over ...

Page 158: ...8 Cord clamp 2 9 Bolt 2 M6 1 7T 10 Hose 1 WP 1 11 Hose 2 WP 1 12 Hose clamp threaded 4 13 Oil cooler 1 U 20 3 Oil cooler 1 U 25 14 Bracket oil cooler 1 U 20 3 Bracket oil cooler 1 U 25 15 Bolt 4 M6 1 7T 16 Bolt 4 M6 1 7T 17 Hose drain 1 18 Hose drain 1 19 Hose clamp threaded 14 2 20 Rubber fitted washer 1 21 Plug 1 22 Plate partition top 1 23 Sound absorber partition top 1 24 Grommet 200 1 25 Plat...

Page 159: ...U20 3 U25 3 WSM Engine Service section III S 7 Radiator assembly view 3 a Radiator b Clamp to the inlet hose c Suction hose to be passed along center d Catch the rubber s hook tightly ...

Page 160: ... B Tightening torque 77 5 90 2N m 7 9 9 2kgf m Third tighten up the bolt C Tightening torque 3 9 5 9N m 0 4 0 6kgf m 2 Keep a clearance of over 20 mm between the tail pipe and counterweight 3 Parts list No Part name Q ty Remarks 1 Packing non asbestos 1 424 2 Bolt 2 M10 1 25 7T 3 Flange muffler 1 4 Exhaust pipe band 2 5 Bolt 2 M10 1 25 7T 6 Plain washer 4 7 Spring washer 2 8 Nut 2 9 Muffler assemb...

Page 161: ... Tightening torque of alternator assembly mounting bolt 39 2 44 1N m 4 0 4 5kgf m 4 Adjusting the V belt tension Pressing the belt with a force of 58 8 68 6 N m 6 7 kgf m readjust the deflection to 7 9 mm 1 Reassembling procedure 1 Connect the hose 1 inlet as shown at left An out of spec angle may cause unusual operating noise 2 Parts list No Part name Q ty Remarks 1 Air cleaner assembly 1 422 2 B...

Page 162: ...U20 3 U25 3 WSM Engine Service section III S 10 B General 1 Engine identification ...

Page 163: ...U20 3 U25 3 WSM Engine Service section III S 11 2 General precaution ...

Page 164: ...U20 3 U25 3 WSM Engine Service section III S 12 3 Tightening torques ...

Page 165: ...U20 3 U25 3 WSM Engine Service section III S 13 4 Troubleshooting ...

Page 166: ...U20 3 U25 3 WSM Engine Service section III S 14 ...

Page 167: ...U20 3 U25 3 WSM Engine Service section III S 15 ...

Page 168: ...U20 3 U25 3 WSM Engine Service section III S 16 5 Servicing specifications ...

Page 169: ...U20 3 U25 3 WSM Engine Service section III S 17 ...

Page 170: ...U20 3 U25 3 WSM Engine Service section III S 18 ...

Page 171: ...U20 3 U25 3 WSM Engine Service section III S 19 ...

Page 172: ...U20 3 U25 3 WSM Engine Service section III S 20 ...

Page 173: ...U20 3 U25 3 WSM Engine Service section III S 21 ...

Page 174: ...U20 3 U25 3 WSM Engine Service section III S 22 ...

Page 175: ...U20 3 U25 3 WSM Engine Service section III S 23 ...

Page 176: ...U20 3 U25 3 WSM Engine Service section III S 24 ...

Page 177: ...U20 3 U25 3 WSM Engine Service section III S 25 6 Maintenance check list ...

Page 178: ...U20 3 U25 3 WSM Engine Service section III S 26 7 Check and maintenance ...

Page 179: ...U20 3 U25 3 WSM Engine Service section III S 27 ...

Page 180: ...U20 3 U25 3 WSM Engine Service section III S 28 ...

Page 181: ...U20 3 U25 3 WSM Engine Service section III S 29 ...

Page 182: ...U20 3 U25 3 WSM Engine Service section III S 30 ...

Page 183: ...U20 3 U25 3 WSM Engine Service section III S 31 ...

Page 184: ...U20 3 U25 3 WSM Engine Service section III S 32 ...

Page 185: ...U20 3 U25 3 WSM Engine Service section III S 33 ...

Page 186: ...U20 3 U25 3 WSM Engine Service section III S 34 ...

Page 187: ...U20 3 U25 3 WSM Engine Service section III S 35 ...

Page 188: ...U20 3 U25 3 WSM Engine Service section III S 36 ...

Page 189: ...U20 3 U25 3 WSM Engine Service section III S 37 ...

Page 190: ...U20 3 U25 3 WSM Engine Service section III S 38 ...

Page 191: ...U20 3 U25 3 WSM Engine Service section III S 39 C Engine body CHECKING AND ADJUSTING ...

Page 192: ...U20 3 U25 3 WSM Engine Service section III S 40 DISASSEMBLING AND ASSEMBLING ...

Page 193: ...U20 3 U25 3 WSM Engine Service section III S 41 1 Draining water and oil 2 External components ...

Page 194: ...U20 3 U25 3 WSM Engine Service section III S 42 3 Cylinder head and valves ...

Page 195: ...U20 3 U25 3 WSM Engine Service section III S 43 ...

Page 196: ...U20 3 U25 3 WSM Engine Service section III S 44 4 Gear case ...

Page 197: ...U20 3 U25 3 WSM Engine Service section III S 45 ...

Page 198: ...U20 3 U25 3 WSM Engine Service section III S 46 ...

Page 199: ...U20 3 U25 3 WSM Engine Service section III S 47 ...

Page 200: ...U20 3 U25 3 WSM Engine Service section III S 48 ...

Page 201: ...U20 3 U25 3 WSM Engine Service section III S 49 ...

Page 202: ...U20 3 U25 3 WSM Engine Service section III S 50 5 Piston and connecting rod ...

Page 203: ...U20 3 U25 3 WSM Engine Service section III S 51 ...

Page 204: ...U20 3 U25 3 WSM Engine Service section III S 52 ...

Page 205: ...U20 3 U25 3 WSM Engine Service section III S 53 6 Flywheel and crankshaft ...

Page 206: ...U20 3 U25 3 WSM Engine Service section III S 54 ...

Page 207: ...U20 3 U25 3 WSM Engine Service section III S 55 SERVICING 1 Cylinder head ...

Page 208: ...U20 3 U25 3 WSM Engine Service section III S 56 ...

Page 209: ...U20 3 U25 3 WSM Engine Service section III S 57 ...

Page 210: ...U20 3 U25 3 WSM Engine Service section III S 58 ...

Page 211: ...U20 3 U25 3 WSM Engine Service section III S 59 ...

Page 212: ...U20 3 U25 3 WSM Engine Service section III S 60 2 Timing gear and camshaft ...

Page 213: ...U20 3 U25 3 WSM Engine Service section III S 61 ...

Page 214: ...U20 3 U25 3 WSM Engine Service section III S 62 3 Piston and connecting rod ...

Page 215: ...U20 3 U25 3 WSM Engine Service section III S 63 ...

Page 216: ...U20 3 U25 3 WSM Engine Service section III S 64 ...

Page 217: ...U20 3 U25 3 WSM Engine Service section III S 65 4 Crankshaft ...

Page 218: ...U20 3 U25 3 WSM Engine Service section III S 66 ...

Page 219: ...U20 3 U25 3 WSM Engine Service section III S 67 ...

Page 220: ...U20 3 U25 3 WSM Engine Service section III S 68 ...

Page 221: ...U20 3 U25 3 WSM Engine Service section III S 69 ...

Page 222: ...U20 3 U25 3 WSM Engine Service section III S 70 ...

Page 223: ...U20 3 U25 3 WSM Engine Service section III S 71 5 Cylinder ...

Page 224: ...U20 3 U25 3 WSM Engine Service section III S 72 ...

Page 225: ...U20 3 U25 3 WSM Engine Service section III S 73 D Lubricating system CHECKING SERVICING 1 Oil pump ...

Page 226: ...U20 3 U25 3 WSM Engine Service section III S 74 ...

Page 227: ...U20 3 U25 3 WSM Engine Service section III S 75 E Cooling system CHECKING 1 Fan belt 2 Radiator ...

Page 228: ...U20 3 U25 3 WSM Engine Service section III S 76 DISASSEMBLING AND ASSEMBLING ...

Page 229: ...U20 3 U25 3 WSM Engine Service section III S 77 ...

Page 230: ...U20 3 U25 3 WSM Engine Service section III S 78 F Fuel system CHECKING AND ADJUSTING 1 Injection pump ...

Page 231: ...U20 3 U25 3 WSM Engine Service section III S 79 ...

Page 232: ...U20 3 U25 3 WSM Engine Service section III S 80 2 Injection nozzle ...

Page 233: ...U20 3 U25 3 WSM Engine Service section III S 81 DISASSEMBLING AND ASSEMBLING 1 Injection pump ...

Page 234: ...U20 3 U25 3 WSM Engine Service section III S 82 2 Injection nozzle ...

Page 235: ...U20 3 U25 3 WSM Engine Service section III S 83 G Electrical system CHECKING 1 Starter ...

Page 236: ...U20 3 U25 3 WSM Engine Service section III S 84 2 Glow plug DISASSEMBLING AND ASSEMBLING 1 Starter ...

Page 237: ...U20 3 U25 3 WSM Engine Service section III S 85 2 Alternator ...

Page 238: ...U20 3 U25 3 WSM Engine Service section III S 86 ...

Page 239: ...U20 3 U25 3 WSM Engine Service section III S 87 ...

Page 240: ...U20 3 U25 3 WSM Engine Service section III S 88 SERVICING 1 Starter ...

Page 241: ...U20 3 U25 3 WSM Engine Service section III S 89 ...

Page 242: ...U20 3 U25 3 WSM Engine Service section III S 90 2 Alternator ...

Page 243: ...U20 3 U25 3 WSM Engine Service section III S 91 ...

Page 244: ...U20 3 U25 3 WSM Engine Service section III S 92 ...

Page 245: ...U20 3 U25 3 WSM Engine Service section III S 93 H Turbo charger system CHECKING ...

Page 246: ...U20 3 U25 3 WSM Engine Service section III S 94 ...

Page 247: ...U20 3 U25 3 WSM Engine Service section III S 95 DISASSEMBLING AND ASSEMBLING ...

Page 248: ...U20 3 U25 3 WSM Engine Service section III S 96 ...

Page 249: ...t section IV M 26 E Pilot valve IV M 27 a Structure specifications IV M 27 b Pilot valve control diagram IV M 29 c Functions IV M 30 F Swivel motor IV M 33 a Structure specifications IV M 33 b Operating principle IV M 34 c Function of negative brake IV M 36 G Rotary joint Swivel joint IV M 37 H Travel motor U20 3 Fujikoshi IV M 39 a Stracture specifications IV M 39 b Operating principle IV M 40 U2...

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Page 251: ...left and the front attachment is moved 4 Pilot valve Kawasaki made redesigned The vertical stroke is made greater from 5 2 mm to 6 4 mm to eliminate jerking at vertical rotation The secondary pressure is also made higher from 19 5 kgf cm2 to 27 0 kgf cm2 for improved controllability 5 Swivel negative brake adopted Release the lever lock and the negative brake gets activated to keep the parked mach...

Page 252: ...Pa 3 9 MPa Swivel motor Maker Eaton Fluid Power Eaton Fluid Power Type 25PB20A1124 C 25PB25A1125 C VNS200S310A VNS165S320A Equivalent capacity 195 cm3 rev 244 cm3 rev Relief pressure 19 6 MPa 16 2 MPa Swivel speed 8 9 rpm 9 2 rpm Torque Theoretical 609 N m 629 N m Travel motor Maker Fujikoshi KAYABA Type PHV 190 39 1 8944A MAG 18V 230E Equivalent capacity 628 328 cm3 rev 774 430 cm3 rev Speed R 2 ...

Page 253: ...9 O ring 1 10 Swash plate 1 30 Ball bearing 1 50 None 70 Washer 2 11 Needle 3 31 Needle bearing 1 51 Plug 1 71 O ring 1 12 Oscillating pin 2 32 Oil seal 1 52 None 72 O ring 1 13 Packing 1 33 Plate spring 4 53 None 14 Spring C 1 34 Snap ring 1 54 None 15 Spring T1 1 35 Snap ring 1 55 None 16 None 36 Snap ring 1 56 Spring pin 1 17 None 37 None 57 None 18 Spring holder 1 38 None 58 None 19 Spring gui...

Page 254: ...on Clockwise viewed from input shaft side Weight about 16kg Test conditions Legend Remarks Hydraulic tempt 50 5 C Input shaft rpm 2 200 rpm q3 5 8 cc rev q4 2 7 cc rev P4 40 kgf cm2 0 0 100 200 300 400 480 2 4 6 8 10 12 14 16 18 20 22 0 2 4 6 8 10 12 14 16 18 20 22 10 45 cc rev P3 210kgf cm2 P3 5kgf cm2 10 3 cc rev P1 P2 100kgf cm2 10 cc rev P1 P2 240kgf cm2 7 cc rev P1 P2 350kgf cm2 5 2 cc rev P1...

Page 255: ...ating direction Weight Test conditions Legend Remarks Hydraulic tempt 50 5 C Input shaft rpm 2 400 rpm q3 8 cc rev q4 2 7 cc rev P4 40 kgf cm2 0 0 100 200 300 400 480 2 4 6 8 10 12 14 16 18 20 22 0 2 4 6 8 10 12 14 16 18 20 22 Discharge Capacity q 1 q 2 cc rev U25 3 Pressure P1 P2 kgf cm2 12 cc rev P3 175kgf cm2 P3 5kgf cm2 11 9 cc rev P1 P2 60kgf cm2 11 6cc rev P1 P2 195kgf cm2 7 8 cc rev P1 P2 3...

Page 256: ...ided with two suction grooves and two discharge grooves as shown in Fig 3 The discharge grooves P1 and P2 are located in the outer and inner sides respectively Every other piston chamber of cylinder barrel gets open to either of these discharge grooves in the valve plate In other words both the inner and outer suction grooves behave just the same way whereas the inner and outer discharge grooves w...

Page 257: ... Bottom MPa kg cm2 24 0 0 3 at 29 l min 24 0 0 3 at 29 l min Boom Rod Boom Bottom Arm Rod Arm Bottom Dozer Bottom 24 0 0 3 at 18 l min 24 0 0 3 at 18 l min Spool operating force of mechanical section Return spring at neutral N kgf 74N 74N at full stroke N kgf 108N 108N Spool operating force of pilot section See below diagram 21 6 at 23 l min 0 3 0 2 21 6 at 29 l min 0 3 0 2 20 6 at 13 l min 0 3 0 ...

Page 258: ......

Page 259: ...WING DOZER 74N at neutral 108N at full stroke BACKWARD 21 PF 3 8 P1 P2 P3 A B 4 M10 1 5 Deepness 10 Tightning torque 26 5 29 4N m UP RIGHT LEFT UP CROWD DELIVERY DUMP BACKWARD ORV ORV ORV ORV MRV TRAVEL STRAIGHT DOZER DOWN LEFT RIGHT SWING SWIVEL SERVICE CROWD FORWARD BOOM BUCKET DUMP down TRAVEL RIGHT FORWARD ARM TRAVEL LEFT MRV MRV ORV ORV ACV TRAVEL STRAIGHT DOZER SWING SWIVEL SERVICE ARM TRAVE...

Page 260: ...N at neutral 108N at full stroke BACKWARD 21 PF 3 8 P1 P2 P3 A B 4 M10 1 5 Deepness 10 Tightening torque 26 5 29 4N m UP RIGHT LEFT UP CROWD DUMP BACKWARD ORV ORV ORV ORV MRV TRAVEL STRAIGHT DOZER DOWN LEFT RIGHT SWING SWIVEL SERVICE CROWD FORWARD BOOM BUCKET DUMP DOWN TRAVEL RIGHT FORWARD ARM MRV MRV ORV ORV ACV TRAVEL STRAIGHT DOZER SWING SWIVEL SERVICE ARM TRAVEL LEFT TRAVEL RIGHT BOOM BUCKET 1...

Page 261: ...19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Q ty 1 1 2 2 2 1 2 2 1 1 2 3 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 5 1 PARTS NAME Valve housing Spool Spring seat Spring Spring seat Cap O ring Socket head bolt Poppet Spring Plug O ring Poppet Spring Spacer Backup ring O ring Body Spring Poppet Spring seat Sleeve Backup ring O ring O ring Backup ring Spool Plug O ring Spring Piston Plug assem...

Page 262: ...AT SPRING CAP SCREW CAP BOLT BOLT POPPET SPRING PLUG Travel right section No 1 2 3 4 5 6 7 Q ty 1 1 2 2 2 4 1 PARTS NAME HOUSING SPOOL O RING BACKUP LING SEAL PLATE BOLT PLUG Inlet section Section C C No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Q ty 1 1 2 2 2 2 1 1 1 2 2 1 1 1 PARTS NAME HOUSING SPOOL O RING WIPER SEAL PLATE SPRING SEAT SPRING CAP SCREW CAP BOLT BOLT POPPET SPRING PLUG Travel left section...

Page 263: ... 9 10 11 12 13 14 15 16 17 18 19 20 Q ty 1 1 1 1 1 2 2 2 2 2 2 4 1 1 1 1 1 1 1 1 PARTS NAME Valve housing Spool Poppet Spring Plug O ring Spring seat Spring Spring seat Cap O ring Socket head bolt Poppet Spring Plug Orifice plug Plug O ring O ring O ring Arm section Section X X ...

Page 264: ... RING Service section No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Q ty 1 1 2 2 2 2 2 4 1 1 1 1 1 1 1 PARTS NAME HOUSING SPOOL SPRING SEAT SPRING SPRING SEAT CAP O RING BOLT POPPET SPRING PLUG O RING O RING POPPET SPRING Swivel section Section C C No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Q ty 1 1 2 2 2 2 1 1 1 2 2 1 1 1 1 Swing section PARTS NAME HOUSING SPOOL O RING WIPER SEAL PLATE SPRING SEAT SPRING CA...

Page 265: ... 1 1 1 2 2 1 1 1 1 Dozer section PARTS NAME HOUSING SPOOL O RING WIPER SEAL PLATE SPRING SEAT SPRING CAP SCREW CAP BOLT BOLT POPPET SPRING PLUG O RING No 1 2 3 4 5 6 7 8 9 10 11 Q ty 1 1 1 1 1 1 2 4 1 1 1 Travel straight section PARTS NAME HOUSING SPOOL SPRING SEAT SPRING SPRING SEAT CAP O RING BOLT CAP FILTER PLUG ...

Page 266: ...ssage gets closed The pressure oil goes through the parallel feeder pushes up the load check valve and flow on to the cylinder bottom Part of return oil from the cylinder bottom flows through the spool throttle first and then through the low pressure passage returning to the tank The remaining oil pushes the check valve open and reaches the cylinder bottom Arm dump Pilot secondary pressure Arm cro...

Page 267: ...The hydraulic oil at port B cylinder rod side is shut off The hydraulic oil at port A cylinder bottom side flows through the passage C and poppet d into the chamber Z Now the anti drift poppet gets closed which prevents the boom from falling Section A A Section B B Port A Port B Poppet d Chamber Z Passage c Pb Pa Port T ...

Page 268: ...s introduced into the port Pa and the control valve spool is moved to the lift The hydraulic oil from the pump flows through parallel passage pushing load check valve The oil then flows through the passage a pushing up the anti drift poppet The oil further goes through the port A The return oil from the port B comes through the throttle into the tank ...

Page 269: ...i drift poppet The power balance at this time is expresses as P1 A1 P2 A2 Where P1 Pressure of the oil from the pump P2 Pressure applied behind the anti drift poppet P1 P2 because of the throttling effect of poppet d A1 Area exposed to the pressure P1 A2 Area exposed to the pressure P2 The anti drift poppet shifts to the left in the above figure A1 A2 but P1 P2 Thus we have P1 A1 P2 A2 Poppet d An...

Page 270: ... The oil in the chamber Z flows through the poppet d and the pin s internal hole and then via the drain port back into the tank Now the pressure in the chamber Z goes down and the return oil from the port A pushes open the anti drift poppet It further flows through the passage a the spool s throttle and the tank passage back into the tank From P V Piston To drain Pin Flowing via this hole into the...

Page 271: ...e poppet d and the pin and into the tank In this design shutting off part A before opening part C the oil at the boom cylinder bottom is kept from flowing to the tank Thus the anti drift poppet can be perfectly pushed open As a result the oil at the boom cylinder bottom is all fed through the control valve back into the tank DR No pressure oil flowing to Pi Poppet d Chamber Z Pressure oil flowing ...

Page 272: ... efficient work 2 Before lifting pipes the front attachment can be positioned exactly to the pipes while the machine is traveling 3 Operating When the boom arm bucket or service port is used while traveling the signal line of the related spool is activated to shut off the passage leading to the tank The Pp port then gets under pressure which switches the spool of the straight travel section So the...

Page 273: ...e boom and another oil flow from pilot pump P4 gets blocked at the boom section 1 3 Now the pilot circuit gets under pressure which shifts the traveling straight spool in the direction of arrow 4 The oil from pump P3 is introduced into the boom section and flows into the boom cylinder 1 1 equv equv equv equv equv equv equv equv equv equv equv equv ...

Page 274: ......

Page 275: ...nd bucket are being used together the pressure oil to the bucket switch is fed via the intermediate orifice The orifice openness is not enough to cover the difference with respect to the attachment load but designed to keep the best balance for simultaneous operation of the boom and bucket orifice with check B B A A ...

Page 276: ...e tank port Fig 3 4 When the pressure at the port P has dropped below the spring s set pressure the pilot popper is pressed against the seat by the spring force and the pressure of chamber A becomes equal to that of port A The main poppet is also pressed against the socket seat resulting in the original state Fig 1 Function of anti cavitation valve 1 This valve works to feed the oil from the tank ...

Page 277: ...stroke B V groove equivalent to 0 25 dia End milled portion Section A A A A Control valve passage to tank When the spool is at neutral position air is blocked at the position B as shown in the figure above and the air in the hydraulic pilot circuit does not return to the tank Hydraulic pilot valve When the spool is moved in full stroke the air bleeding section opens as shown in the figure and the ...

Page 278: ...actory adjusted to a converted secondary pressure of 0 5 1 MPa depending on models The spool 201 is kept against the push rod 212 by the return spring 221 Tilt the operating lever and the push rod 212 is pressed down and the spring seat goes down too This affects the secondary pressure setting spring 241 The oil inlet primary pressure port P and outlet tank port T are located at the casing 101 and...

Page 279: ...U20 3 U25 3 WSM Hydraulic system Mechanism section IV M 28 ...

Page 280: ...U20 3 U25 3 WSM Hydraulic system Mechanism section IV M 29 b Pilot valve control diagram ...

Page 281: ... the spring for the above spool used to control the output pressure 2 Functions of major parts The spool 201 is designed to switch between two oil passages one passage is for the pressure oil from the hydraulic pump to go to the port P first and then to the output ports 1 2 3 and 4 The other is for the pressure oil to go from the output port to the port T The secondary pressure setting spring 241 ...

Page 282: ...ical application of the pilot valve 1 With the lever at neutral See Fig 2 The secondary pressure setting spring 241 which determines the pilot valve output pressure does not exert upon the spool 201 The spool 201 is therefore pressed down by the return spring 221 spring seat 216 which interconnects the output ports 2 and 4 and the port T In this state the output pressure is kept at the same level ...

Page 283: ...and 4 and port P get closed whereas the ports 2 and 4 and port T get open When this pressure has dropped below the set level the ports 2 and 4 and port P get open whereas the ports 2 and 4 and port T get closed 4 With the lever too tilted depending on the model On some models if the lever is tilted beyond a certain angle the spool top end comes in contact with the push rod bottom This means that t...

Page 284: ... Theoretical RPM rpm 63 4 at 12 4 L min 75 4 at 18 4 L min Theoretical output torque N m kgf m 609 62 1 at 19 6 MPa 200kgf cm2 629 64 0 at 16 2 MPa 165 kgf cm2 Theoretical brake torque N m kgf m 440 43 1 440 43 1 Brake releasing pleasure MPa kgf m 2 0 20 2 2 0 20 2 Shockless valve type VNS 200S 310A VNS 165S 320A Releaf valve pressure MPa kgf cm2 19 6 200 at 10L min 16 2 165 at 20L min ...

Page 285: ...il through the other 6 holes Similarly the valve plate has 7 oil holes These oil holes connect with the rotor subassemblies 7 compartments In this way the 7 oil holes of the valve plate come in alignment with some of the 12 oil holes of the disc valve making the rotor subassembly circuit 3 Now under hydraulic pressure the rotor of the rotor subassembly starts the planetary motion The autorotation ...

Page 286: ...tor makes 1 14 turn and that the compartments 1 7 and 6 receive the high pressure oil The rotors center point B moves around point A to point B Fig 3 illustrates that point B has shifted up to B In other words the rotors center makes 6 7 turn around point A from B thorough B to B In Fig 4 point B is back to point B completing a cycle At this time the rotor moves in the opposite direction of point ...

Page 287: ...doing the friction plate is held in this poison by a friction force Because the pinion gear and the friction plate are spline coupled through ring gear the cylinder block is held and thus the motor is braked 2 Negative brake release On load condition A pilot pressure is applied at the P port generating a driving force to the negative brake piston In this state the piston driving force surpasses th...

Page 288: ...80 090 100 110 120 130 140 Q ty 1 1 9 1 1 1 1 1 4 2 1 4 4 4 PARTS NAME Rotary joint assy Seal Seal Shaft Collor Collor Circlip Plug Plug PT1 8 Plug PT1 4 Plate Bolt Bolt Washer No 010 020 030 040 050 060 070 080 090 100 110 120 130 140 Q ty 1 1 1 1 1 1 1 1 4 4 2 4 4 4 PARTS NAME Rotary joint assy Seal Seal Shaft Collor Collor Circlip Plug Plug PT1 8 Plug PT1 4 Plate Bolt Bolt Washer ...

Page 289: ...U20 3 U25 3 WSM Hydraulic system Mechanism section IV M 38 Fixed undercarriage U20 3 U25 3 Retractable undercarriage U20 3 ...

Page 290: ...section IV M 39 H Travel motor U20 3 Fujikoshi a Structure specifications Specifications Theoretical numbers Type Displacements 1F 2F cc rev 16 1 8 4 Realuction gear ration 1 39 Max output torque N m kgf m 2156 220 Max output rpm 1F 2F 36 6 70 2 ...

Page 291: ...Principle of operation 1 Operating principle of wheel motor Description of operation The PHV series travelling motor has a stationary main body composed of a hydraulic motor and hydraulic valve and a rotating main body composed of a simple planetary gear reducer ...

Page 292: ... gear S2 is single reduced through the gears S2 b2 a2 This single reduced revolution is double reduced through the gears S1 b1 a1 spline coupled with the carrier 2 The reduced revolution is transmitted to the rotating main body through the annular gears a1 and a2 providing travelling driving force The reduction ratio of a simple two step planetary gear reducer is generally expressed as shown below...

Page 293: ...alve is supplied to the valve plate 5 When the pressure oil is supplied to the port A the oil flows into the cylinder port which corresponds to the port A in the cylinder barrel 4 and presses the piston 6 This pressing force is converted to turning force through the swash plate 7 and the resulting turning force is transmitted to the shaft 3 spline coupled with the cylinder barrel 4 The return oil ...

Page 294: ...barrel and the swash plate angle becomes α At this time the motor is of large capacity When the speed selector lever is switched to the g2nd speed position the operating pressure is conducted through the two speed spool to the control room and the control piston moves until the face II of the swash plate touches the body 2 fixing the swash plate angle at β At this time the motor is of small capaci...

Page 295: ...port B These pro cesses make the hydraulic motor rotate When the pressure oil is supplied through the port B the above mentioned processes are reversed and the hydraulic motor rotates reversely When the pressure oil supplied through the port A is made unpressurized the spring force works to return the spool valve to the left At this time the oil in the room D controls the speed at which the spool ...

Page 296: ...U20 3 U25 3 WSM Hydraulic system Mechanism section IV M 45 U25 3 KAYABA a Structure specifications ...

Page 297: ...Working pressure MPa 21 6 Supply flow rate L min 27 6 Output torque theoretical KN m 1st speed 2 66 2nd speed 1 75 Revolutions theoretical rpm 1st speed 35 6 2nd speed 64 2 Drain pressure MPa Normal 0 2 Maximum instantaneous 0 5 Counter balance valve Spool switching pressure MPa 0 23 Check valve cracking pressure 0 03 or less Two speed control valve Switching pressure MPa 0 59 or more Reducer Stru...

Page 298: ...inst this force which produces a turning force Ft The sum of the turning forces produced through the piston S As 14 on the high pressure side makes the cylinder block 7 rotate which torque is transmitted to the shaft 2 through the splines making the shaft 2 rotate The output torque and revolution of the piston motor obtained based on the above mentioned operating principle are determined by the su...

Page 299: ...counter balance valve is used to stop the axial piston motor and to prevent it from overrunning When the control valve is in the neutral position because no pressure is applied to the ports P1 and P2 the ports M1 and M2 31 1 are blocked by the plunger and check valve 31 2 and therefore the motor does not rotate ...

Page 300: ... passes through the orifice L and acts on the end face of the plunger 31 1 working to move the plunger to the right with a force proportionate to the pressure against the spring R 37 on the opposite side When a certain pressure is reached the plunger 31 1 starts to move to the right As a result the return oil passes through the plunger helix flows into the port P2 while applying a back pressure to...

Page 301: ...lunger throttle becomes smaller when the plunger moves In addition using an inertial force the piston motor continues rotating pumping action of motor As a result the port M2 side pressure rises When the plunger moves the hydraulic oil in the pilot pressure room L passes through the orifice L to control the speed of the plunger In this manner the speed of the plunger is controlled so that the pist...

Page 302: ...e port T via the ports Pi1 and Pi2 Therefore no force for pushing the swash plate 5 is applied to the swash plate control piston 19 The moment acting on the swash plate with the steel balls 6 serving as the tilting center is expressed as shown bellow where ƒ F is the sum of the thrusts of the piston S As 15 and Fs1 and Fs2 are the forces of the spring 9 The swash plate is stabilized on the face a ...

Page 303: ...essed as shown bellow where Σ F is the sum of the thrusts of the piston S As 15 Fs1 is the force of the spring 9 Fp is the pushing force of the swash plate control piston and Fs1 is the force of the spring 20 The swash plate is stabilized on the face b and the swash plate angle becomes β providing the revolutions for the 2nd high speed of the motor When the engine is stopped the spring 9 returns t...

Page 304: ...driving force is transmitted to the ring gear 7 via the planetary gear 5 of the planetary carrier 6 fixed on the body The driving force is also transmitted via the 1st planetary gear 2 The output rotation is reverse to the input rotation The reduction ratio i is expressed as shown below where i1 and i2 are the 1st step reduction ratio and 2nd step reduction ratio respectively Reduction ratio i i i...

Page 305: ...ion of anti cavitation valve 1 Construction The anti cavitation mechanism functions in sync with the counterbalance mechanism Unlike conventional types of counterbalance mechanism the oil passages A B and C as well as the check valves B and C are added in this circuit ...

Page 306: ...the spring s counter force and shifts to the right as shown in the figure below In the meanwhile the valve switches from M2 to P2 which gets the motor started Usual counterbalance action At the same time the oil passage A goes under high pressure Thanks to the action of the check valve C however the pressure oil is kept from leaking out toward the low pressure side oil pas sage C ...

Page 307: ...ant speed With the motor running at constant speed the oil passage A stays under high pressure Thanks to the action of the check valve C however the pressure oil is kept from leaking out toward the low pressure side Thus the motor runs stably with the anti cavitation mechanism intact ...

Page 308: ...port P2 Because there is no enough oil flow from P1 cavitation occurs at P1 and M1 The anti cavitation mechanism works to avoid this Until the counterbalance valve returns to its original state P1 is connected with the oil passage A In this condition the hydraulic oil flows in this route oil passage M2 counterbalance throttle C oil passage C check valve C oil passage A port P1 and oil passage M1 I...

Page 309: ...U25 3 WSM Hydraulic system Mechanism section IV M 58 4 Motor stop The anti cavitation function keeps on until the oil passage A and port P1 are shut off as shown in the figure below at the indicated positions ...

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Page 311: ...U20 3 U25 3 WSM Hydraulic system Mechanism section IV M 59 I Hydraulic circuit diagram a U20 3 Fixed undercarriage ...

Page 312: ...U20 3 U25 3 WSM Hydraulic system Mechanism section IV M 60 b U20 3 Retractable undercarriage ...

Page 313: ...U20 3 U25 3 WSM Hydraulic system Mechanism section IV M 61 c U25 3 ...

Page 314: ... L Pilot value R Pilot filter Change valve Control valve Swivel motor Rotary joint Travel motor L Travel motor R Change valve for sp 1 way 2 way Travel lock cylinder Hydraulic oil tank Oil cooler Boom cylinder Arm cylinder Bullcket cylinder Swing cylinder Dozer cylinder Upper roller Track rollers Grease tension cylinder Idler No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 ...

Page 315: ...rain measurement IV S 36 d Measurement of block performance IV S 38 e Operating speed IV S 39 f Straight travel performance IV S 41 g Control and Traveling lever operating force IV S 41 h Control and Traveling lever stroke IV S 41 i Cylinder natural fall amount IV S 42 j Control and Traveling lever operating force IV S 42 k Lever stroke IV S 42 D Disassembling and Assembling IV S 43 a Pump IV S 43...

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Page 317: ... to stop The engine rpm is not stable Emission is whitish or bluish Emission is blackish or dark grayish The output power is short Too much oil is consumed Fuel gets mixed with the oil Water gets mixed with the oil The oil pressure is too low The oil pressure is too high The engine gets overheated The glow lamp fails to light up The charge lamp fails to light up The charge lamp fails to go out The...

Page 318: ...r oil or combustion line The engine cover is poorly lined with thermal insulation The operator runs the machine in the wrong way The attachment is not as specified for the job The hydraulic system is in trouble Cover mounting bolts are nuts are loose A pipe or hose is in contact with its nearby part Unusual noise is heard from a pin or bushing Unusual noise is heard from the engine Unusual noise i...

Page 319: ...aged if the boom bucket and right travel mechanism fail too Overhaul or replace the pump The swing dozer and swivel mechanism fail or respond too slow or too weak 1 Main relief valve P3 not at specified pressure Check the main relief valve P3 and readjust as required 2 P3 line pump internal parts seized or damaged Overhaul or replace the pump The boom alone fails or responds too slow or too weak 1...

Page 320: ...erhaul the cylinder and replace the sealing The bucket cylinder and arm cylinder allow too much gravity fall 1 Overload relief valve not at specified pressure Check the overload relief valve and repair as required 2 Control valve spool scratched or spring broken Check the spool and repair as required 3 Bucket cylinder or arm cylinder rod packing broken Overhaul the cylinder and replace the sealing...

Page 321: ...ump 3 Unusual noise or unusual vibrations occur cavitation phenomenon 1 Air or water mixed in hydraulic oil 2 Suction strainer clogged 3 Suction pipe clogged or throttled 4 Attached pump in trouble if provided 5 Piston shoe poorly crimped 6 Pump loosely mounted 7 Coupling defective 1 Retighten the circuit connections the suction pipe in particular Replace if water is mixed in 2 Clean or replace th...

Page 322: ...he pipe connections Poor valve timing due to wrong disassembling reassembling procedures Disassemble and reassemble again for good valve timing Oil leak Oil seal scratched or worn Replace the oil seal Repair or replace if the shaft seal contact surface is scratched or worn Loose bolt or plug resulting in oil leak at joints from O ring Tighten the bolt and plug to their specified torques See also i...

Page 323: ...nd replace 10 Control valve internal parts damaged Overhaul clean and replace 3 No enough power Too slow motion 2 Pilot valve spool malfunctioning Check the performance Overhaul and clean 3 Control valve spool stick malfunctioning Check the performance Overhaul and clean 4 Pilot secondary pressure unspecified Measure the pressure 6 Brake valve pressure unspecified Measure the pressure Overhaul cle...

Page 324: ... malfunctioning Check the performance Overhaul and clean 7 Anti void valve malfunctioning valve seat defective Check the performance Overhaul and clean 6 Brake valve pressure unspecified Measure the pressure Overhaul clean and readjust 8 Motor drain too much Measure the drain amount Problem Cause Correction ...

Page 325: ...mbers given in the figure below correspond to those in the troubles at a glance 4 If the trouble is found in either direction reverse the right and left hoses and see if the trouble occurs in the other direction 5 If the hoses have been reversed and the trouble found in the other direction it means that the trouble spot is upstream If still in the same direction the trouble spot is downstream 6 Ho...

Page 326: ... in trouble in either direction reverse the two one touch coupler hoses below the valve See if the trouble happens in the other direction this time 1 See if the swivel section spool moves well 2 If the spool fails to move smoothly check for foreign matters scratches deformation etc For servicing refer to page IV S 60 1 Measure the secondary pressure between the pilot valve and the control valve 2 ...

Page 327: ...move the bucket by hand using your reaction force Make sure the swivel mechanism starts and the brake gets applied when it gets locked For measuring and servicing refer to pages IV S 35 and IV S 78 respectively 1 Measure the brake valve pressure Before the measurement bring the bucket end in contact with something fixed 2 Make sure the pressure is as specified 3 Readjust the relief valve or disass...

Page 328: ...rench that is 45 mm or so tall For servicing refer to page IV S 78 1 Remove the steps 2 The drain hose is between the swivel motor and drain pipe Disconnect this hose from the drain pipe alone Plug one end of a 30 cm or so long spare hose and connect the other end to the drain pipe 3 Do and lock the swiveling with the bucket end in contact with something fixed and measure their respective drain am...

Page 329: ...vel lever linkages out of alignment Readjust the linkage 2 Right and left control valve spools out of alignment Overhaul and clean the control valve Replace as required 3 Internal leak in rotary joint on one side Overhaul the rotary joint Replace the seal 4 Counterbalance valve spool stuck Overhaul and clean the counterbalance valve Replace as required 5 Too much difference between right and left ...

Page 330: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 15 1 Travel mechanism check points ...

Page 331: ... valve refer to IV S 63 2 Remove the cap and spool Check and clean them up 3 Clean up the filter in the cap too Checking the counterbalance valve and high low speed selector valve 1 For disassembling and reassembling the valves refer to IV S 102 2 Remove the plug and spool Check and clean them up 3 Checking the counterbalance valve and high low speed selector valve travel motor ...

Page 332: ...to the openings 3 Raise the pump pressure and make sure the main relief pressure reaches the specified level 1 Make sure there is nothing unusual between the pump and rotary joint 2 Disconnect the marked hoses as shown at left Put plugs to the openings 3 Raise the pump pressure and make sure the main relief pressure reaches the specified level A Two speed B Dozer lower bottom C Dozer upper rod D T...

Page 333: ... load pressure P1 P2 Main relief pressure MPa kgf cm2 21 6 220 21 6 220 P3 Main relief pressure MPa kgf cm2 20 6 210 17 2 175 Pilot primary pressure MPa kgf cm2 3 9 40 3 9 40 Theoretical discharge capacity P1 P2 Main pump cc rev 10 5 10 5 12 0 12 0 P3 Pp pump cc rev 5 8 2 7 8 0 2 7 Theoretical discharge capacity at rated load P1 P2 Main pump L min 21 5 24 5 21 5 24 5 27 5 30 5 27 5 30 5 P3 Pp pump...

Page 334: ... Turning speed Turning direction 83 84 P4 ISO VG46 or equivalent 50 5 C 2 200 rpm Clockwise 5 8 cc rev 2 7 cc rev 4 1 MPa Measuring conditions Oil used Oiltemperature Turningspeed Turningdirection 83 84 P4 ISOVG46orequivalent 50 5 C 2 400 rpm Clockwise 8 cc rev 2 7 cc rev 4 1 MPa Q P1 P2 l min 0 0 100 200 300 400 480 2 4 6 8 10 12 14 16 18 20 22 0 2 4 6 8 10 12 14 16 18 20 22 Discharge Capacity q ...

Page 335: ... relief valve c Swing anti void valve d Overload relief valve e P1 P2 main relief valve No Valve location Operating work Unit U20 3 U25 3 Remarks 1 P1 Main relief valve Bucket crowd MPa kgf cm2 21 6 220 21 6 220 U20 3 at 29 L min U25 3 at 29 L min 2 P2 Main relief valve Arm crowd or dump MPa kgf cm2 21 6 220 21 6 220 U20 3 at 29 L min U25 3 at 29 L min 3 P3 Main relief valve Swing Left or Right MP...

Page 336: ...21 1 215 17 6 180 4 Pilot primary pressure All pilot lines MPa kgf cm2 4 1 0 5 42 5 4 2 0 5 43 5 No Valve location Operating work Unit U20 3 U25 3 Remarks 5 Control valve Boom up Boom down MPa kgf cm2 24 245 24 245 at 29 L min 6 Control valve Bucket crowd 7 Control valve Arm dump Arm crowd 8 Control valve Dozer down 9 Control valve Dozer up MPa kgf cm2 24 245 24 245 at 18 L min 10 Swivel motor Swi...

Page 337: ... at 18 4 L min Brake valve pressure MPa kg cm2 19 6 200 16 2 165 Drain amount at lock L min Drain amount while rotating L min Swivel speed rpm 8 9 8 9 pinion swivel teeth 3 times rotation swivel speed sec 20 2 19 5 Swivel block performance at engine stop mm min 0 0 Swivel block performance at engine running mm min 130 140 Bucket empty Capable swivel rotation angle deg 23 7 21 5 Bucket crowded Play...

Page 338: ...2 U25 3 at 27 6 L min Relief valve pressure Mpa kg cm2 21 6 213 21 6 213 Climbing ability deg 30 30 Max traction force 1F KN kgf 15 5 1580 20 3 2070 Slip 70 theoretical torque Oil temp 50 5 C 2F KN kgf 8 1 826 9 7 990 Relief 60 theoretical torque Traveling block performance mm 10min 300 300 10 min engine stop Testing angle 20deg Traveling speed Rubber Iron 1F km h 2 2 2 5 2F km h 4 2 4 5 10m trave...

Page 339: ...oke Bucket cylinder Dump sec 1 8 2 4 2 9 1 8 2 4 2 9 Swing cylinder Left Canopy sec 4 8 5 8 7 0 4 1 5 1 6 1 Cylinder full stroke Cabin sec 4 8 5 8 7 0 4 1 5 1 6 1 Swing cylinder Right Canopy sec 4 6 5 6 6 7 4 6 5 6 6 7 Cabin sec 4 6 5 6 6 7 4 6 5 6 6 7 Dozer cylinder Up sec 2 3 2 9 3 5 2 0 2 6 3 1 Cylinder full stroke Dozer cylinder Down sec 3 0 3 6 4 4 2 3 2 9 3 5 A New machine reference value B ...

Page 340: ...747 76 Piston screw size mm M30 M30 Width for tightening by spanner mm 50 50 Bucket Tube I D Rod O D mm 60 35 60 35 Stroke mm 416 416 Max retraction length mm 679 741 Seal Kit No RB411 71791 RB511 71791 Piston tightening torque N m kgf m 735 75 462 47 Piston screw size mm M27 M27 Width for tightening by spanner mm 41 41 Swing Tube I D Rod O D mm 60 35 60 35 Stroke mm 420 420 Max retraction length ...

Page 341: ...5 80 39 36 Arm mm 48 48 40 40 40 65 80 39 36 Bucket mm 48 48 50 50 35 60 75 36 36 Swing mm 38 38 35 35 35 60 75 34 36 Dozer mm 45 45 50 50 40 80 96 39 39 Unit A B C D E F G H J Port screw size Remarks Boom mm 48 48 45 50 40 70 85 39 39 Arm mm 48 48 40 40 40 70 85 48 48 Bucket mm 48 48 50 50 35 65 80 36 36 Swing mm 38 38 35 35 35 60 75 34 36 Dozer mm 45 45 50 50 45 90 108 44 42 ...

Page 342: ... 2 M30 2 Set screw 6 9 0 7 16 2 1 7 M6 1 M8 1 25 Tightening torque Thread size Adhesive U20 3 U25 3 U20 3 U25 3 Cylinder head 343 35 0 382 39 0 M72 2 M77 2 Three bond 1901 Piston 644 65 7 747 76 2 M30 2 M30 2 Set screw 16 2 1 7 16 2 1 7 M8 1 25 M8 1 25 Tightening torque Thread size Adhesive U20 3 U25 3 U20 3 U25 3 Cylinder head 304 31 0 343 35 0 M67 2 M72 2 Three bond 1901 Piston 735 75 0 462 47 1...

Page 343: ... 855 87 2 M33 2 M36 3 Set screw 16 2 1 7 16 2 1 7 M8 1 25 M8 1 25 Tightening torque Thread size Adhesive U20 3 U25 3 U20 3 U25 3 Cylinder head 304 31 0 304 31 0 M67 2 M67 2 Three bond 1901 Piston 470 48 0 470 48 0 M27 2 M27 2 Set screw 6 86 0 7 6 86 0 7 M6 1 M6 1 Tightening torque Thread size Adhesive U20 3 U25 3 U20 3 U25 3 Cylinder head 304 31 0 M67 2 Three bond 1901 Piston 333 34 0 M24 2 Set sc...

Page 344: ...ssure to the pump discharge side Measure the discharge rate at the specified rpm to check the volumetric efficiency 1 The pump s volumetric efficiency is proportional to the pump rpm and inversely proportional to the load pressure During the test keep the engine at its maximum rpm 2 The volumetric efficiency is the ratio of the discharge rate per pump turn cc rev to the theoretical discharge rate ...

Page 345: ...he pilot filter Set the pressure gauge 3 Start the engine Take the reading at the maximum speed Take 3 measurements and take the average Keep the oil temperature at 50 5 C 2 Pilot secondary pressure in moving up the boom 1 Remove the steps and swivel cover 2 There is the hose between the pilot valve and control valve Disconnect this hose from the control valve alone 3 Attach the T joint and set th...

Page 346: ...left P3 Swivel swing and dozer 2 Start the engine Check the circuit to be measured for oil leak 3 With the engine running at maximum rpm operate the lever to relieve the cylinder 4 Repeat the pressure measurement 3 times obtain the average and adopt it as measured value Measure the pressure at oil temperature of 50 5 C Left pilot valve Right pilot valve Left pilot valve Right pilot valve Back Back...

Page 347: ... Travel right 11 Boom 12 Bucket 2 Adjusting procedure 1 Loosen the lock nut of the relief valve 2 Turn the adjusting screw with a hex wrench to set the pressure and tighten the lock nut after setting Clockwise turning increases the pressure and counterclockwise turning decreases it 3 With the engine running at maximum rpm operate the lever and check the set pressure P3 3 P2 P1 ...

Page 348: ... cm2 higher than that of the overload relief valve 3 With the engine running at maximum rpm tuck in the arm relieve the cylinder and measure the set pressure 4 Repeat the pressure measurement 3 times obtain the average and adopt it as measured value 5 After the measurement return the pressure of the main relief valve to the original set value Measure the pressure at oil temperature of 50 5 C Contr...

Page 349: ...e the lever and check the set pressure 3 After the measurement return the pressure of the main relief valve to the original set pressure 1 Measuring procedure 1 Remove the adaptor plug P3 discharge of main pump discharge side and connect thereto a pressured gauge 2 Support the bucket with a strongly built stand 3 Operate the swivel lever slowly and measure the brake valve relief pressure while ope...

Page 350: ...ion and measure the pressure 3 Repeat the pressure measurement 3 times obtain the average and adopt it as measured value Measure the pressure at oil temperature of 50 5 C 1 Measuring procedure 1 Stop the engine disconnect the travel two speed selector hose of the selector valve using the vacuum pump and set the pressure gauge 2 With the engine running at maximum rpm step on the two speed pedal and...

Page 351: ...e will do to the travel motor drain port Photo Left travel motor U25 3 3 Lift up the crawler and bring it into measurable posture 4 With the engine running at maximum rpm rotate the crawler for 1 minute and measure the amount of hydraulic oil collected in a container 5 Repeat the pressure measurement 3 times obtain the average and adopt it as measured value Caution Be very careful not to put your ...

Page 352: ...sconnected 3 Dismount the vacuum pump 4 Bring the front attachment into travel posture and hold up the bucket 1 m above the ground 5 With the engine running at maximum rpm do the swiveling for 1 minute and measure the amount of oil collected in a container 6 Repeat the pressure measurement 3 times obtain the average and adopt it as measured value Caution Pay full attention to the surrounding durin...

Page 353: ...ure the displacement generated for 1 minute 4 Start the engine unlock the lever while idling and start the measurement 5 A bucket load should be JIS crowded x specific gravity 1 8 6 Conduct the measurement at hydraulic temperature of 50 5 C Allowable range 1 Measuring procedure 1 Park the machine on a 20 degree slope and bring the front attachments into traveling posture 2 Mark the lower travel fr...

Page 354: ...cket 72 kg 2 Fully retract the arm cylinder and fully extend the bucket cylinder 3 Adjust the bucket bottom approx 1 m above the ground 4 Mark the boom arm and bucket cylinder rods 5 Measure the amount of gravity fall 10 minutes later using a measuring scale Hydraulic oil temp 50 5 C 1 Fully retract the arm cylinder and bucket cylinder 2 Operate the engine at maximum rpm 3 Measure the time require...

Page 355: ... not included U20 3 U25 3 1 Bring the bucket down to the ground in such a posture that the dozer can be operated at full stroke as shown in the figure 2 Operate the engine at maximum rpm 3 Measure the time required for full stroke of the dozer cylinder U20 3 U25 3 1 Bring the front attachments into the posture as shown in the figure 2 Operate the engine at maximum rpm 3 Measure the time required f...

Page 356: ... measurement with regard to the right and left levers 2 Start the engine move the levers for full stroke and measure the maximum operating force in relief state 3 Repeat the measurement 3 times obtain the average and adopt it as measured value Conduct measurement at oil temperature of 50 5 C 1 Stop the engine 2 Move each of the travel boom arm bucket and dozer control levers from neutral to full s...

Page 357: ...tance after 10 min 1 Stop the engine 2 Measure force of right and left control and traveling levers 3 Start the engine operate the control lever or traveling lever for a full stroke and measure the max operating force 4 Make three measurements and take their average 5 Hydraulic oil temperature must be 50 5 C 122 9 F 1 Stop the engine 2 Move each lever from neutral to full stroke end and measure ea...

Page 358: ...round and stop the engine 2 Open the bonnet remove the bonnet left cover and dismount the muffler 3 Mount a vacuum pump and disconnect the hydraulic hose and suction hose from the pump 4 Remove the two pump mounting bolts Tightening torque of bolt 77 5 90 2N m 7 9 9 2kgf m 5 Pull the pump assembly toward the counterweight separate it from the pump coupling and dismount it ...

Page 359: ...pply an appropriate amount of grease to the spline before mounting the pump CAUTION Do not allow grease onto the rubber parts Rubber may be deteriorated 2 Tightening torque of coupling mounting bolt 48 1 55 9N m 4 9 5 7kgf m CAUTION Do not apply screw LOCTITE Rubber may be deteriorated ...

Page 360: ...Flange suction 1 4 04811 10440 O ring 1 5 01123 61020 Bolt 4 M10 1 5 7T 6 RB201 63881 Elbow pipe joint F3x2 T1 1 P2 7 68311 64321 Straight pipe joint 1 P4 8 RB511 6398Δ T pipe joint 3 3 3 1 P1 9 RB511 6399Δ Elbow pipe joint 3 4 25 1 P1 10 RB511 6397Δ Hydraulic hose 5 8 1 11 RB511 6396Δ Plug G1 2 hose 1 12 RB511 6394Δ Cushion plug 1 13 68551 51251 Cushion 2 14 RB511 6395Δ Collar 2 15 04015 60100 Pl...

Page 361: ...ing 1 7 Shoe 10 27 Pin with hole 1 47 None 67 Collar 1 8 Shoe holder 1 28 None 48 None 68 Hex bolt 2 9 Barrel holder 1 29 None 49 Hex socket plug 5 69 O ring 1 10 Swash plate 1 30 Ball bearing 1 50 None 70 Washer 2 11 Needle 3 31 Needle bearing 1 51 Plug 1 71 O ring 1 12 Rocking pin 2 32 Oil seal 1 52 None 72 O ring 1 13 Packing 1 33 Plate spring 4 53 None 14 Spring C 1 34 Snap ring 1 54 None 15 S...

Page 362: ...semble the pump with care using necessary tools Take proper measures against scratches foreign matters and other troubles 1 Disassembling 1 Dismounting the gear pump Remove the two M8x25 hex bolts 68 2 Removal of hex socket lock screw Loosen the hex nut 61 completely and remove the hex socket lock screw 60 Tools Wrench 13 mm hex wrench 4 mm Preferably record the stretch out distance of this hex so...

Page 363: ...r two temporary bolts and separate the body S kit The body can be separated easily by tapping on the spring inserting part of the body H with a plastic or copper hammer 4 Disassembling the body S kit Take the following parts out of the body S kit in this order spring T 15 spring holder 18 cylinder barrel 4 swash plate 10 rocking pin 12 stopper pin A 25 two plain springs 33 stopper pin B 26 two pla...

Page 364: ... screw 60 is screwed in the hex socket lock screw hole of the body H 2 the spring guide 19 can be taken out 7 Disassembling the cylinder barrel kit Remove the shoe holder 8 to which the piston shoe assemblies 6 and 7 are mounted out of the cylinder barrel kit and dismount the barrel holder 9 and needle valve 11 in this order Then remove the snap ring 35 retainer 24 spring C 14 and retainer 24 in t...

Page 365: ...1 Assembling the oil seal Assemble the shaft 3 kit oil seal 32 and snap ring 34 in this order into the body S 1 Apply a small amount of grease to the lip and outer surface of the oil seal and mount the oil seal using a specific tool and tapping with a hammer At this time replace the oil seal with new one Temporary mounting of the body S 1 on the body H 2 facilitates the work 2 Assembling the cylin...

Page 366: ...and set the spherical portions of the spring holder 18 into the holes of the swash plate 10 5 Assembling the body H kit Photo 12 Mount the spring holder 18 to the body H 2 Then position the valve plate 5 by the spring pin 56 of the body H 2 and gently mount it in place The cylinder barrel 4 slides over the surface of the valve plate having fine grooves Use care not to confuse the mounting directio...

Page 367: ...air or replace the pump 2 Pump oil amount drops extremely Discharge pressure does not rise 1 Engine rpm drop 2 Pump mounting coupling defective 3 Pump internal parts seized or broken 1 Readjust the rpm 2 Repair or replace the pump coupling 3 Repair or replace the pump 3 Unusual noise or vibrations Cavitation 1 Air or water mixed in hydraulic oil 2 Suction strainer clogged 3 Suction pipe clogged or...

Page 368: ... pipe joint 3 3 35 Pipe joint S G3 8 G3 8 Straight pipe joint 3 3 65 Pipe joint L G1 2 G3 8 Pipe joint L G3 G3 Straight pipe joint Pipe joint S F3 8 F1 4 None None None Pipe joint L G1 4 G1 4 Pilot T pipe joint F2 Straight pipe joint 4 4 100 Pipe joint L G3 8 16 Flange faced elbow Pipe joint T G3 8 Pipe joint L G1 2 G3 8 Pipe joint S G3 8 16 Q ty Remarks Remarks No Part No Part name Q ty Remarks N...

Page 369: ...on IV S 54 Rod Rod No Part No Part name Bolt U25 3 EU None Plain washer Bolt Bolt Pin Snap pin Snap pin Rod 190 Rod 130 Plain washer Dozer Snap pin Service port spec Pin Plain washer Rod 130 Plain washer Travel Right Snap pin Snap pin Q ty Remarks ...

Page 370: ...raulic circuit diagram U 20 3 Upper Communi c at i n gval v e Dozer Swing Swivel Service Arm Travel left Travel right Boom Bucket Dump Lower Front Front Low Right Lower Ri g ht Crowd Left Left High Dump Back Back Crowd Upper Model KVSE 36 10 Maker Kayaba Industry Co Ltd Weight Approx 31 kg Tightening torque of tie rod 26 5 29 4 N m ...

Page 371: ...Boom section Component parts 1 Poppet 2 Poppet b5 Overload relief valve A Spring seat B O ring C Spring seat D Spring Component parts 3 Poppet 4 Anti drift valve b1 Overload relief valve b2 Overload relief valve A Spring seat B O ring C Spring seat D Spring I O ring 5 Poppet Spring Spacer O ring Backup ring ...

Page 372: ...valve 1 Plug assembly 2 Piston 3 Spring 4 Plug 5 Spool 6 Sleeve 7 Poppet 8 Spring seat 9 Spring Tightening torque of plug assembly 1 69 78 N m Reassembling precautions The spool 5 is directional Do not confuse its inserting direction Component parts E Cap screw F Spring G Wiper H O ring I O ring 6 Poppet spring ...

Page 373: ...aulic system Service section IV S 58 4 Inlet section Component parts a1 Main relief valve 1 O ring Component part of main relief valve 1 Adjuster washer 6 Spring 2 Nut 7 Piston 3 Spring 8 Sleeve 4 Pilot poppet 9 Cap 5 Plug ...

Page 374: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 59 5 Travel left section Component parts E Cap screw F Spring G Wiper H O ring I O ring 7 Poppet spring ...

Page 375: ...Swivel section Component parts 8 Poppet b3 Overload relief valve b4 Overload relief valve A Spring seat B O ring C Spring seat D Spring E O ring Component parts 9 Poppet 10 Poppet E Cap screw F Spring G Wiper H O ring Component parts 11 Poppet A Spring seat B O ring C Spring seat D Spring I O ring ...

Page 376: ... S 61 9 Swing section 12 Poppet spring Component parts 13 Poppet 14 Anti void valve E Cap screw F Spring G Wiper H O ring I O ring Component parts of anti void valve 1 Cap 2 Sleeve 3 Spring 4 Spring 5 Plug Tightening torque of anti void valve 69 78 N m ...

Page 377: ...arts of overload relief valve 1 Adjuster nut washer 6 Spring 2 Spring 7 Piston 3 Pilot poppet 8 Poppet 4 Plug 9 Sleeve 5 Spring 10 Cap Tightening torque of overload relief valve 69 78 N m Check the seats of the poppets 3 and 8 carefully for dust deposits or metal chippings If there is dent or scratch on the seat face repair or replace Component parts 16 Poppet E Cap screw F Spring G Wiper H O ring...

Page 378: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 63 12 Communicating valve Component parts a2 Main relief valve A Spring seat B O ring C Spring seat D Spring ...

Page 379: ...part should be toward the lever Bring the stepped part of the nut to the opposite side of the grip and fit the projection of the rubber bellows securely to the stepped part 2 Play of lever Less than 2 mm 3 Control lever mounting dimension Refer to the left figure 517 mm reference value 1 Tightening torque of hydraulic adaptor G1 4 24 5 29 4 N m 2 5 3 0 kgf m 2 Check the fitting part of the quick a...

Page 380: ... L P V 1 2 3 4 ports 5 RD411 61761 Pipe joint S G1 4 8 4 3 B S made R L P V P port L P V T port 6 68728 76151 Adaptor 1 R P V T port 7 RP201 61872 Pipe joint 1 R P V T port 04811 00110 O ring 14 For 1 4 Left P V Right P V Back Front Front Front Back Back Position for Use Color of Hose Tape Position for Use Color of Hose Tape 1 Bucket crowd Pink 1 Swivel left Red 2 Boom down Sky blue 2 Arm dump Blu...

Page 381: ... 47 1 2 9 Checkpoints Criteria Remarks Leak amount Replace the pilot valve assembly with new one if the oil leak exceeds 1000 cc min with the steering wheel at neutral or 2000 cc min while in operation Conditions Primary pressure 2 95 MPa Oil viscosity 23 mm2 s Spool If the sliding face is worn over 10 μ more than the non sliding one replace the pilot valve assembly with new one This amount of wea...

Page 382: ...take care in loosening and drawing out the joint 301 The plate 151 plug 211 and push rod 212 may pop out together when taking out the joint 6 Remove the plate 151 When the return spring 221 is strong in force Photo 7 7 When the return spring 221 is weak in force Photo 7 8 7 When the return spring 221 is weak in force the sliding resistance of the O ring holds the plug 211 inside the casing 101 Usi...

Page 383: ...ste cloth wipe kerosene away from the parts Do not wipe dirty parts in kerosene from the beginning because otherwise they might get scratched Keep them dipped until dirt fat and grease become loose enough off the parts Be attentive to keep the kerosene clean enough Otherwise the parts may get scratched leading to poor performance when reassembled Do not dry up the parts with compressed air Dust an...

Page 384: ... ring 122 to the casing 101 Photo 7 20 2 Install the port plate 111 with the hex socket bolt 125 and seal washer 121 in between on the casing 101 Photos 7 21 and 7 22 Carefully position the spring pin 126 in the casing hole Replace the seal washer 121 with new one 3 Tighten the hex socket bolt 125 to the specified torque Photo 7 23 Alternately tighten the two bolts 4 Install the washer 2 217 secon...

Page 385: ...33 and 7 34 Photo 7 33 shows the jig in its specified position 12 Fit the disc 302 to the joint 301 Photo 7 35 Screw in the disc until it comes into even contact with the four push rods 212 WARNING Carefully adjust the final position of the disc 302 If it is screwed in too much the secondary pressure with the lever at neutral may be wrongly applied causing the machine to malfunction 13 Apply the a...

Page 386: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 71 Photo 7 1 Photo 7 2 Photo 7 3 Photo 7 4 Photo 7 5 Photo 7 6 ...

Page 387: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 72 Photo 7 7 Photo 7 8 Photo 7 9 Photo 7 10 Photo 7 11 Photo 7 12 ...

Page 388: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 73 Photo 7 13 Photo 7 14 Photo 7 15 Photo 7 16 Photo 7 17 Photo 7 18 ...

Page 389: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 74 Photo 7 19 Photo 7 20 Photo 7 21 Photo 7 22 Photo 7 23 Photo 7 24 ...

Page 390: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 75 Photo 7 25 Photo 7 26 Photo 7 27 Photo 7 28 Photo 7 29 Photo 7 30 ...

Page 391: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 76 Photo 7 31 Photo 7 32 Photo 7 33 Photo 7 34 Photo 7 35 Photo 7 36 ...

Page 392: ...in question Problem Causes Corrections Secondary pressure failure to rise 1 Primary pressure too low 2 Secondary pressure spring 241 broken or worn out 3 Too large a gap between the spool 201 and casing 101 4 Steering wheel too loose 1 Ensure the specified primary pressure 2 Replace the spring with new one 3 Replace the remotely operated valve with new one 4 Disassemble and reassemble the related ...

Page 393: ...left operation panel together with the seat stand 6 Be careful not to bend the pilot hose 7 Disconnect the panel related wire harnesses and cables 8 Remove the bolts which fix the right operation panel and seat stand Tilt the seat stand forward paying attention not to bend the pilot hose Confirm the safety 9 Dismount the seat stand 10 Disconnect the return hose and return pipe running between the ...

Page 394: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 79 13 Remove the 4 motor mounting bolts Tightening torque 103 0 117 7 N m 10 5 12 0 kgf m Apply screw loctite Loctite 271 14 Dismount the motor ...

Page 395: ...alve 4 Brake valve 5 Anti void valve No 1 2 3 4 5 6 Part No RB411 6128 RB511 6128 68881 34933 68191 61831 RC601 63721 RC101 63801 04810 00110 04810 00140 01138 61240 Part name Motor assembly Swivel Motor assembly Swivel Flange based elbow O ring O ring Q ty Remarks U 20 3 Black 613 U 25 Blue Av Bv P T For 1 4P For 3 8 Av M12 1 25 9T Tightening torque of hydraulic adaptor G1 4 24 5 29 4N m 2 5 3 0k...

Page 396: ...lar Ring gear Snap ring for shaft Piston Ring Friction plate Mating plate Spring Front bearing Snap ring for hole Bearing cover Rear bearing Snap ring X ring O ring O ring Hex socket bolt Shaft face seal Geroller Drive Valve plate Valve drive Valve Balancing ring Spring Inner face seal Pin Outer face seal Valve housing assembly Valve housing Steel ball Plug O ring Spring Plug Plug O ring O ring O ...

Page 397: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 82 ...

Page 398: ... Seat 2 4 Piston 2 5 M27 plug 4 M27 6 O ring 4 A40001 24 1BP24 7 Seal set 2 AH0597A 8 Orifice plug 2 φ0 40 9 Orifice plug 2 φ0 35 10 Filter 4 100 mesh 11 Collar 4 12 Spring 2 13 Shim 2 14 Plug 4 A42041 Rc1 8 15 O ring 4 A40001 18 1BP18 16 Hex socket bolt 2 DW0024A 055 M10 L55 17 Nameplate 1 18 Rivet 2 0 Seal kit AH0615A ...

Page 399: ... and dirt off them Also use due care not to give damage or dent to them Replace the seals with new ones Apply grease to the new seals beforehand When disassembling the parts clean around the workshop and prepare plastic cases for keeping the removed parts Before disassembly clean around the ports of the motor and remove paint from the connections using a wire brush Disassembling procedure 1 Dismou...

Page 400: ... valve housing At this time use care not to lose the spring Do not disassemble the valve housing unless necessary 4 Remove the balancing ring valve and valve seat 5 Remove the valve drive and geroller 6 Dismount the drive Do not disassemble the pinion gear unless necessary ...

Page 401: ...e 8 springs 8 Remove the piston The piston will be easily removed by blowing air through the brake release port Keep in mind however that the piston may pop out 9 Remove the ring Remove it with a screwdriver as shown at left Be careful not to scratch the ring 10 Remove the friction plates and mating plates Remove them paying attention to their orders and numbers ...

Page 402: ... IV S 87 11 Remove the snap ring for shaft Bear in mind that the snap ring may pop out 12 Remove the snap ring for hole Bear in mind that the snap ring may pop out 13 Strike out the pinion gear together with the bearing 14 Remove the X ring 60 mm dia ...

Page 403: ...rts after washing and checking them for any damage 15 Apply hydraulic oil to the X ring before mounting 16 Mount the pinion gear and the snap rings for hole and shaft 17 Check the friction plates and mating plates for scratches and dust deposits and assemble them with care not to confuse their orders ...

Page 404: ...sembling 19 Check the outer O ring of the piston for scratches and distortion and apply hydraulic oil to it before assembling 20 Apply grease to the bearing housing before assembling paying attention not to let the spring drop Tightening torque 34 3 N m 35 kgf m Apply LOCTITE No 242 21 Fit the 2 different O rings into the O ring grooves of the flange mounting Insert the drive ...

Page 405: ...ice section IV S 90 22 Mount the geroller Align it with the drain hole 23 Insert the valve drive 24 Fit the 2 different O rings into the O ring grooves of the valve plate Mount the valve plate onto the geroller Align it with the drain hole ...

Page 406: ...tor rotating direction Mount it with care according to the left figure Wrong timing will rotate the motor in the wrong direction which causes danger 27 Fit the spring and pin to the valve housing Fit the outer face seal and inner face seal to the balancing ring Mount the balancing ring with its notch in the pin into the valve housing ...

Page 407: ...O ring grooves of the valve housing Insert a screwdriver or the like from the B port of valve housing and mount the valve housing to the valve while holding the balancing ring in place Align it with the drain hole 29 Tighten the hex bolt 53 N m Tightening torque 59 N m 6 kgf m Apply LOCTITE No 242 ...

Page 408: ...plug to the valve housing Tightening torque 59 N m 6 kgf m Now the swivel motor has been reassembled Before mounting it to the machine check the motor rotating direction Rotating direction as viewed from the pinion shaft side Av port pressurization Clockwise Bv port pressurization Counterclockwise ...

Page 409: ...urn bucket and boom hoses from the control valve 4 Disconnect the travel dozer 2 speed select and drain hoses Disconnect them from the upper side shaft side 5 When disconnecting the travel motor hose from the control valve loosen the return joint 90 degrees It helps disconnect the hose easily 6 Disconnect the 10 hoses including the travel dozer 2 speed select and drain hoses from the bottom ...

Page 410: ...s of the lip 3 When connecting the shaft to the body apply grease to the outer and inner faces 4 Tightening torque of swivel joint assembly and stay 77 5 90 2 N m 7 9 9 2 kgf m Apply screw LOCTITE LOCTITE 271 5 When mounting the plugs PT1 8 PT1 4 tighten them so that they do not stretch out of the shaft end No Part No Part name Q ty Remarks 1 RB411 6232Δ Shaft Swivel joint 1 2 RC411 6234Δ Collar S...

Page 411: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 96 Insert the seal ring using a specific tool Seal inserting tool Tool No KS000 00130 ...

Page 412: ...T 3 35358 27371 Plain spring 4 4 RC601 63721 Pipe joint L G1 4 G1 4 2 A B 5 69254 78491 Pipe joint L G1 4 G1 4 1 C 6 RP201 61812 Pipe joint L G3 8 G3 8 3 D F G 7 68311 64321 Straight pipe joint 1 E 8 RC411 63881 Pipe joint Bushing G1 4 1 H 9 RD401 63951 Elbow pipe joint G4 13 1 H 04810 00110 ring 5 For 1 4 A B C H 04810 00140 ring 4 For 3 8 A B C H 10 06112 52027 Straight pipe joint 2 B C 11 RP301...

Page 413: ...or cover and then remove the high pressure hose and drain hose using a vacuum pump 3 Remove the wheel motor mounting bolt and remove the wheel motor from the track frame Tightening torque of motor track frame sprocket 166 7 196 1 N m 17 0 20 0 kgf m Apply screw LOCTITE LOCTITE No 271 2 Reassembling procedure 1 When installing the wheel motor on the track frame face the port side to the front 2 Fac...

Page 414: ...side E Right forward Right P2 upper side F Left backward Left P2 lower side G Right backward Right P1 lower side H Drain Right Left drain port upper side No Part No Part name Q ty Remarks 1 RB411 1443Δ Drive sprocket 2 111 2 01128 61025 Bolt 18 M10 1 5 9T 3 RB411 6129Δ Motor assembly wheel 2 Fujikoshi made 614 4 01128 61025 Bolt 16 M10 1 5 9T 5 RB411 6394Δ Straight pipe joint 3 3 35 4 A B 6 06112 ...

Page 415: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 100 3 Component parts of wheel motor ...

Page 416: ...il seal 1 5 Swash plate 1 6 Steel ball 2 7 Cylinder block 1 8 Spring seat 1 9 Spring 1 10 Washer 1 11 Snap ring 1 12 Pin 3 13 Retainer holder 1 14 Retainer plate 1 15 Piston assembly 9 19 Piston assembly 2 Part No Name Q ty 20 Spring 2 25 Valve plate 1 26 Pin 1 27 Ball bearing 1 28 O ring 1 29 O ring 3 30 Base plate 1 31 Spool assembly 1 31 1 Spool 1 31 2 Check valve 2 31 3 Spring 2 31 4 Plug 2 31...

Page 417: ...tion using a wire brush or the like 3 Put a marking on each part before disassembling so that it can be put back in place at the time of reassembling 4 Carefully handle the removed parts so that they are not damaged 5 Well wash the removed parts with washing oil etc 6 Check the removed parts for abnormal wear or seizure Remove burrs etc if any 7 The seals and snap rings should be replaced with new...

Page 418: ... spool and spring into the body 1 4 Tighten the plug both sides to which the O ring is fitted Tightening torque of plug 46 51 N m 4 7 5 3 kgf m Take care that the spool and spring are positioned and oriented properly 5 Insert the shuttle spool and needle both sides in to the body 1 ...

Page 419: ...ng torque of plug 12 22 N m 1 2 2 3 kgf m Width across flat of hexagon 5 mm 7 Press fit the bearing and spring pin into the body 1 Then fit the O rings 2 places 8 Press fit the oil seal into the body 2 CAUTION 1 Apply grease to between the lips of the oil seal 2 Press fit the oil seal in the direction shown in the figure below ...

Page 420: ...the parallel pin to the body 2 10 Press fit the bearing onto the shaft CAUTION The bearing cannot be disassembled because it is press fitted 11 Fit the control piston steel ball and shaft to the body 2 CAUTION Take care not to allow the shaft to damage the oil seal ...

Page 421: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 106 12 Fit the swash plate 13 Fit the retainer spring and retainer to the cylinder barrel in this order and fix them with the snap ring ...

Page 422: ... pin at the time of disassembling assembling 15 Fit the retainer holder to the cylinder barrel 16 Using the shoe holder assembly and barrel holder assemble the cylinder barrel assembly CAUTION Apply hydraulic oil to the seven holes in the cylinder barrel 17 Fit the cylinder barrel assembly to the body 2 so that the shoe touches the swash plate ...

Page 423: ...the valve plate 2 Applying grease to the back surface iron surface of the valve plate will prevent it from coming off easily 19 Combine the body 1 and body 2 20 Tighten with the hex socket bolt Tightening torque of M8 bolt 28 4 30 4 N m 2 8 3 1 kgf m Width across flat of hexagon 5 mm When fixing the motor with a vise protect the body with aluminum plates etc ...

Page 424: ...rvice section IV S 109 2 Reassembling the reducer 1 Fit the bearing to the main body 2 Fit the snap ring for hole 3 Fit the bearing 4 Fit the floating seat combined with the O ring If it is difficult to fit it apply grease to the O ring ...

Page 425: ...nd the hydraulic motor and fix them with the snap ring 1 Degrease the seat surface of the floating seat 2 If it is difficult to fit the main body evenly hit the periphery of the main body with a resin hammer to fit it 3 Fit the snap ring while clamping the reducer main body flange and hydraulic motor flange with a squill vise hydraulic press etc 4 Adjust the bearing preload with the thickness of t...

Page 426: ... b1 and needle to the body 2 in this order 8 Fit the thrust plate 1 and fix it with the snap ring CAUTION Fit the plate with the convex surface of the inside diameter side faced upward 9 Fit the gear S1 to the carrier II and fix it with the snap ring 10 Fit the thrust washer to the carrier II ...

Page 427: ... gear b2 and needle to the carrier II in this order 12 Fit the gear S2 13 Fit the thrust plate II and fix it with the snap ring to assemble the carrier II assembly CAUTION Fit the plate with the convex surface faced upward 14 Fit the carrier II assembly to the main body ...

Page 428: ... to the main body 1 Apply grease to the O ring and fit the cover horizontally while taking care not to damage it 2 Align the upper and lower tapped holes G3 8 with the notches in the main body 18 Fit the O snap ring and fix the cover 1 Put a flatblade screwdriver on the end face of the O snap ring and strike it in the circumferential direction ...

Page 429: ...AUTION 1 As shown in the figure below use the flange of the plug to prevent the cover from turning Tightening torque 46 51 N m 4 7 5 2 kgf m Width across flat of hexagon 8 mm 20 Fit the flanged plug G1 8 to which the O ring is fitted CAUTION 1 Tightening torque 12 22 N m 1 2 2 3 kgf m Width across flat of hexagon 5 mm ...

Page 430: ...figure below 1 Floating seal 2 Flange holder 3 Guide jig 2 Fit the floating seal using the mounting jig see the figure below 1 Flange holder 2 Mounting jig 3 Guide jig 2 Place the other floating seal concentrically 1 Floating seal 3 Press fit the angular bearing into the flange holder using the mounting jig see the figure below 1 Angular bearing 2 Flange holder 3 Mounting jig ...

Page 431: ...press fit the housing onto the angular bearing 1 Housing 2 Press fitting jig 6 Tighten the ring nut using the tightening jig When the ring nut is tightened so as to leave no clearance between the ring nut and angular bearing measure the load after turning the housing several turns The load starting load measured at this time is assumed to be F kgf Tighten the ring nut so that the starting load bec...

Page 432: ...plug at two points in order to prevent it from getting loose 9 Put the steel balls in the unit 1 Steel ball Number of steel balls 10 Wind seal tape around the plug and tighten it Tightening torque of plug 0 7 0 9 kgf m 11 Fit the thrust washer planetary gear B bearing roller and collar ...

Page 433: ...e snap ring to the sun gear and fit the sun gear 14 Attach the spring pin bearing inner bearing roller and planetary gear A to the holder and fit the holder 15 Fit the drive gear 1 Holder 2 Planetary gear A 3 Drive gear 4 Spring pin 5 Bearing roller 6 Bearing inner 16 Fit the thrust plate 1 Thrust plate 17 Apply grease to the O ring and fit it to the cover Fit the cover to the housing so that the ...

Page 434: ...al tape around the plug and tighten it Tightening torque of plug 7 8 1 0 N m 20 Press fit the oil seal into the flange holder using the mounting jig see the figure below 1 Mounting jig 21 Press fit the ball bearing onto the shaft using the press fitting jig see the figure below 1 Shaft 2 Bearing 3 Press fitting jig 22 Press fit the shaft subassembly into the flange holder using the mounting jig se...

Page 435: ... Swash plate 24 Attach the collar spring and washer to the cylinder block and fit the snap ring using the mounting jig see the figure below 25 Apply grease to the pins and fit them into the three holes in the cylinder block 1 Pin 26 Fit the retainer holder retainer plate and piston subassembly Apply hydraulic oil to the nine holes in the cylinder block 1 Retainer plate 2 Retainer holder 3 Piston a...

Page 436: ...inder block subassembly using the spline in the shaft as a guide 28 While pushing the cylinder block by hand check that the spring works Apply hydraulic oil to the sliding part of the cylinder block 1 Cylinder block 29 Fit the O ring and pin to the flange holder Apply grease to the O ring 1 O ring 2 Pin ...

Page 437: ... 30 Press fit the ball bearing into the base plate using the press fitting jig see the figure below 31 Fit the pin and crimp it at two at two points 32 Apply grease to the back surface of the valve plate and fit it to the base plate 1 Valve plate 2 Base plate ...

Page 438: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 123 33 Fit the base plate and tighten the socket head bolt Tightening torque of socket head bolt 37 0 1 9 N m ...

Page 439: ...g torque of plug 27 0 2 45 N m 1 Plunger assembly 36 Fit the plunger assembly to the base plate Fit the plunger assembly while turning it so that it will not bind Apply hydraulic oil to the plunger subassembly 37 Fit the spring sheet and spring 38 Attach the O ring to the cap and fit the cap to the base plate by tightening it Apply grease to the O ring Tightening torque 157 8 N m ...

Page 440: ...ol and fit the spool to the base plate Apply hydraulic oil to the spool and insert it while turning it 40 Attach the O ring to the plug and fit the plug to the base plate Tightening torque of plug 36 8 2 5 N m 41 Fit the O ring to the valve body Apply a small amount of grease to the O ring ...

Page 441: ...ulic system Service section IV S 126 42 Fit the valve assembly to the base plate Tightening torque 15 2 0 8 N m 43 Fit the check valve and spring to the valve body 44 Tighten the plug Tightening torque of plug 36 8 2 5 N m ...

Page 442: ...ug to the base plate Tightening torque of plug 22 6 1 0 N m 1 Cap 2 Plug 46 Inject the specified amount of gear oil see below through the plug screw hole and tighten the plug Wind seal tape around the plug Tightening torque of plug 22 6 1 0 N m 1 Plug Oil type Amount Diamond Hipoid Oil 90 Mitsubishi 0 35L ...

Page 443: ...mbling the boom cylinder 1 Drain oil from the cylinder 2 Fix the cylinder with a vise Support the cylinder tube with a wooden board 3 Straighten the lock washer 3 Hammer 4 Chisel 5 Straighten 4 Remove the cylinder head while loosening the screw on the cylinder head 6 Pipe 7 Hook wrench Supplement ...

Page 444: ... is tightened and punch crimped at two points scrape away the punched portions with a hand drill loosen the setscrew and remove the steel ball How to use the steel ball to prevent the nut from turning By tightening the setscrew fix the steel ball at a position decentered from the nut rod center line by L Fig 1 When the screw is loosened and the nut rod turns the ball turns and moves to dig into th...

Page 445: ...system Service section IV S 130 7 Fix the piston rod with a vise Support the rod with a wooden board 8 Vise 9 Wooden board 8 Set a spanner on the hex nut portion of the piston and loosen the piston 9 Remove the piston IMPORTANT ...

Page 446: ...S 131 10 Remove the cushion bearing and holder 11 Pull out the cylinder head Release the piston rod from the vise 2 Component parts of boom cylinder 1 Cylinder tube 2 Piston rod 3 Piston 4 Cushion bearing 5 Holder 6 Cylinder head 7 Setscrew 8 Steel ball ...

Page 447: ... mm 4 Measuring the wear in the rod and bush 1 Measure the outside diameter of the piston rod and the inside diameter of the bush of the cylinder head section and determine the clearance 5 Measuring the wear in the tube and piston ring 1 Measure the inside diameter of the cylinder tube 2 Measure the outside diameter of the piston ring and determine the clearance Rod size Gap Standard value φ25 40m...

Page 448: ...r High pressure hose Pilot hose Q ty 1 1 1 1 1 1 U25 3 EU U20 3 EU RB411 6321Δ RB411 6322Δ RB411 6323Δ RB411 6324Δ RB419 6325Δ RB419 6326Δ No 1 2 3 Location Between pump and control valve Between pump and control valve Between pump and control valve Between pump and line filter Between line filter and accumulator Between accumulator and control valve Remarks Fixed foot P1 P2 P3 P4 P4 P4 Part No 4 ...

Page 449: ...U20 3 U25 3 WSM Hydraulic system Service section IV S 134 2 Return drain hose 1 Return drain hose routing 2 Return drain hose routing ...

Page 450: ... 25 Low pressure hose Pilot hose 1 2 1 1 BetweenP V right andP V left Between C V and return pipe P V drain Boom lock drain RB411 6334Δ RB411 6356Δ Part No Hydrauic tank Control valve Return pipe Oil cooler Swivel motor Rod Rod Dozer Swing Arm Travel left Travel right Swivel Reserve Rod Rod Rod Bottom Boom Bottom Bucket Backward Backward Left Bottom Bottom Bottom Forward Forward Right Communicatin...

Page 451: ...rvice section IV S 136 3 Blade travel hose 1 Blade swing hose routing 2 Travel hose routing rotary joint upper Important The hydraulic hose for blade swing should be replaced every two years or 400 hours of operation whichever is earlier ...

Page 452: ...8 19 20 21 22 23 24 25 26 27 Location Part No Q ty 1 1 1 1 1 1 1 1 1 1 1 C V R J C V R J C V R J C V R J Between C V and swivel M Between C V and swivel M BetweenC Vandswingcylinderbottom BetweenC Vandswingcylinderrod C V R J C V R J Travelleftforward Travelleftbackward Travelrightforward Travelrightbackward Swivel left Swivel right Swing left Swing right Dozer up Dozer down U 20 3 RB411 6441Δ RB4...

Page 453: ...nd return pipe Boom lock drain RB411 6356Δ Hydraulic hose 1 4 1 430 G1 4 1500 03 G1 4 Nitta made 635 030 11 Between C V and P V right Boom up RB411 6341Δ Hydraulic hose 1 4 1 1820 Gray G1 4 1500 03 Quick 634 010 12 Between C V and P V right Boom down RB411 6342Δ Hydraulic hose 1 4 1 1920 Sky blue G1 4 1500 03 Quick 634 020 13 Between C V and C V Lock valve release RB411 6343Δ Hydraulic hose 1 4 1 ...

Page 454: ...55311 4126Δ Cord band 55311 4126Δ Cord band 55311 4126Δ 1 Cord band 55311 4126Δ Clamp the travel lock hose pilot hose and round bar guide together 1 2 Cord band 55311 4126Δ Clamp at the taping white portion of the hose 2 3 Cord band 55311 4126Δ Clamp the hose and round bar guide front only together 3 Cord band 55311 4126Δ ...

Page 455: ...rque of hex socket bolt 10 3 92 N m 0 4 kgf m Relief valve set pressure 3 9 MPa 40 kgf cm2 Hydraulic circuit diagram Parts list No Part No Part name Q ty Remarks 1 RB411 6191Δ Valve assembly selector 1 2 RC411 63841 Pipe joint T F2 F3 1 P 3 RP201 61892 Pipe joint L G1 4 G1 4 1 B 4 68591 63231 Washer based elbow 2 A B 5 RC101 63831 T pipe joint F2 1 B 6 RB411 6391Δ Elbow pipe joint G3 8 13 1 T 0481...

Page 456: ...wo speed Tape color White C V communicating valve Travel M brake release Line filter Accumulator Accumulator C V communicating valve Pump P4 No Part No Part name Q ty Remarks 1 RB411 6191Δ Valve assembly selector 1 633 2 RP201 61812 Pipe joint L G3 8 G3 8 1 P 3 RP201 61892 Pipe joint L G1 4 G1 4 1 B 4 68591 63231 Washer based elbow 2 A B 5 RP802 61931 Pipe joint cross G1 4 1 B 6 RB411 6391Δ Elbow ...

Page 457: ...ion The incision should be oriented correctly 4th P Filter Selector valve No Part No Part name Q ty Remarks 1 RB419 6281Δ Accumulator 1 2 RB419 6385Δ Pipe joint accumulator 1 3 01133 61025 Bolt 2 4 RP201 6181Δ Pipe joint L G3 8 G3 8 1 5 RB419 6383Δ Straight pipe joint G3 1 6 RD119 6283Δ Valve assembly check 1 7 68311 6432Δ Straight pipe joint 2 8 RB419 6325Δ Hydraulic hose 3 8 P4 2 1 1 9 RB419 632...

Page 458: ... 1 way circuit to reduce the back pressure IMPORTANT When the equipment auger crusher telescopic arm which need 2 way circuit will be used position the lever to the CLOSED position No Part No Part name Q ty Remarks 11 RB419 9258Δ Hydraulic hose 1 2 third line 1 12 RD418 9640Δ Valve assembly third line 1 13 RD418 9642Δ Bolt 1 14 RB419 9255Δ Plate third line 1 15 01123 60820 Bolt 2 16 RB419 9261Δ Ho...

Page 459: ...0 XQFWLRQ RI PDLQ FLUFXLW 9 0 D DWWHU FLUFXLW 9 0 E 6DIHW 5HOD FLUFXLW XWRPDWLF UHOHDVH IXQFWLRQ 9 0 F XWR JORZ FLUFXLW 9 0 G XHO FRQWURO FLUFXLW 9 0 H QJLQH RLO SUHVVXUH VHQVRU FLUFXLW 9 0 I RUQ FLUFXLW 9 0 J DE RUNLQJ ODPS FLUFXLW 9 0 K 0HWHU SDQHO 9 0 L HDWHU FLUFXLW 9 0 M 7UDYHO KL VSHHG FRQWURO FLUFXLW 9 0 ...

Page 460: ......

Page 461: ...ox Key switch Work lamp switch Meter panel Power outlet relay Horn relay Cab relay Earth Horn Main harness Hi low switch Glow relay Auto release relay Slow blow fuse Travel hi low solenoid Unload solenoid Engine oil switch Engine harness Alternator Auto release stabilize relay Or Power outlet Battery Water temp sensor Gauge Safety lock relay B Light relay Y Check relay Er Starter motor Engine stop...

Page 462: ...ied through the above circuit all the time 2 A 60A fuse is added close to the alternator because otherwise part of the harness may get short circuited due to the alternator s current generated while the engine is running In this way the devices and har ness can be protected against burn out M 1 AC 3 Key SW Stater motor Alternator OFF 60A 50A Battery ...

Page 463: ...lternator has reached the specified rpm N 1 in the figure below the auto release controller is activated to turn off by the auto release relay 2 With the auto release relay off the starter motor current is interrupted to stop the starter motor 3 In this way the starter motor can be protected against seizure even if the key switch fails to get back ...

Page 464: ...s turned on again to light up the glow lamp 4 As indicated in Fig 3 Timer curve the pre glow time glow lamp on time t is compensated depend ing on the water temperature 5 Once the current flows to the relay coil the battery voltage starts flowing to the glow plug Reference NOR logic circuit The NOR logic circuit is a composite circuit of OR gate and NOT gate Water temp sensor signal Key SW ST sign...

Page 465: ... Water temp C Thermistor resistance Ω Pre glow time sec 140 58 2 55 100 155 2 73 80 277 2 95 60 530 3 37 40 1100 4 22 20 2525 5 85 10 3997 7 12 0 6544 8 77 10 11123 10 81 20 19716 12 00 30 36630 12 00 40 71770 12 00 Key Switch Glow lamp Glow relay Pre glow time t SEC Water temp C Sensor Open Fig 3 Timer curve ...

Page 466: ...sensor has a thermistor When the sensor is well below the fuel level the resistance value is high enough to allow no current to the warning lamp If the fuel level has dropped below spec ified however the thermistor gets exposed to the air and becomes smaller in resistance This allows the current to flow to the warning lamp that will light up 2 11 3 2 E F AC ST B OFF 10A IG IG 6P 12P METER METER FU...

Page 467: ...ger Now the fuel injection pump is ready to get the engine started Being attracted upward the plunger pushes and opens the contact which discontinues the cur rent flow to the pull in coil With the current still flowing to the holding coil the plunger stays in this position Turn the key switch to the OFF position and the current flow to the holding coil is also interrupted By the force of the retur...

Page 468: ...gf cm2 5 Insulation resistance 3MΩ or more 1 In normal condition When the engine lube oil pressure goes up the contact of oil switch 6 opens to turn off the lamp 2 In trouble When the above pressure comes down the con tact of oil switch 6 closes to turn on the lamp Operating pressure of oil switch Ref value 0 5 kgf cm2 7 1 psi 0 05 MPa 1 Terminal 5 Contact rivet 2 Insulator 6 Contact 3 Spring 7 Bo...

Page 469: ...nction Shown above is the horn drive circuit When the horn switch is pressed current flows to the horn relay to get its contact P1 closed The current from the battery now flows directly through the horn coil and the contact P2 which magnetizes the core and attracts the moving plate Then the contact P2 opens itself and the current is interrupted The magnetic force then disappears and the spring loa...

Page 470: ...r information 1 Function of diode Prevention of horn switch by absorbing the surge current Inductive type of load such as solenoid valve generates arc spark at switch point This diode installed parallel to solenoid valve let the surge current energy flow back to coil to consume as a joule heat In this way surge current won t flow to horn switch 4 3 2 1 6 9 5 7 8 Diode Switch Relay Horn ...

Page 471: ...Horn SW is off position When horn switch is off current doesn t flow through relay So relay remains off condition and horn doesn t sound When horn switch is on position current flows through relay magnetizes it and acti vates horn Horn SW Diode GND Horn Horn SW GND Diode Horn ...

Page 472: ...mp circuit M Ac Light SW Light Relay Heater relay Heater Heater SW Beacon SW Wiper SW Working light left Working light right Wiper Washer Room Lamp Radio Beacon Spare Spare Spare Main Harness Cabin Harness B Lo Hi Working Light B OFF Start 5A 10A 50A 15A 10A 20A 15A Battery 5A ...

Page 473: ...mps go out 3 During usual operation the indicator lamps are ready to light up according to their respective circuits Let s take some examples The glow lamp stays on while the current is flowing to the glow plug The AI lamp is kept on during the AI function The charge lamp lights up if the charge voltage drops below the specified level The fuel level lamp lights up if the fuel runs short 12p connec...

Page 474: ...witch still on and the heater motor usually keeps turning by inertial force and generates electricity Since the relay terminal is always grounded however the self generated current causes an inverse electromagnetic action which interrupts the motor quickly This process is called electromagnetic braking 3 Purpose of relay Without the relay the above mentioned self generated current at a stop of the...

Page 475: ...nal 1 3 Turn on and off the travel hi speed switch and check the continuity and discontinuity 4 Check the continuity of the travel hi speed solenoid coil and measure its resistance 5 If there is no problem with the above steps it means the electrical system functions Now go to the hydraulic system 6 Possible troubles with the hydraulic system include stuck solenoid spool poorly performing pilot pu...

Page 476: ......

Page 477: ...e section V S 1 V Electrical system Service section A Wire harness installation S 2 a Front S 3 b Engine S 4 c Swivel frame S 5 d Around seet S 7 B Troubleshooting S 10 a Engine S 10 b Meter panel S 11 c Others S 13 d Check instructions S 14 ...

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Page 479: ... together with the fuel hose 3 Securely connect the coupler terminal etc so that they will not be disconnected when pulled by some force 4 Securely clamp the harness at the clamping position 5 Harness fixed clamp 1 Anchor type Insert to the engaging section 2 Screw type Insert to the bottom of threaded portion 3 Plug in type Insert until locked The harness should not protrude from the corrugate sl...

Page 480: ...U20 3 U25 3 WSM Electrical system Service section V S 3 a Front ...

Page 481: ...stem Service section V S 4 b Engine 1 Nut tightening torque for connecting cable to starter terminal 5 9 11 8N m 0 6 1 2kgf m From front Grommet Glow plug Fuel pump Engine stop SOL Water temperature sensor Water temperature sensor ...

Page 482: ...U20 3 U25 3 WSM Electrical system Service section V S 5 c Swivel frame ...

Page 483: ...U20 3 U25 3 WSM Electrical system Service section V S 6 Around battery ...

Page 484: ...e light switch Connect it to the key switch Connect it to the horn switch Connect it to the panel Orange tape Yellow tape Black tape Slow blow fuse To fuel sensor and working light harness Red tape Grommet Connect the engine harness to the main harness Horn relay Automatic release stabilization relay 3 3 3 3 3 3 Green coupler Cabin specification only heater Blue coupler Brown tape Green tape ...

Page 485: ... for installation of starter switch 4 0 5 0 N m 0 4 0 51 kgf m 3 Hold the starter switch in the starting position and check that the starter stops immediately after engine startup automatic release Lever lock switch Lever lock SOL Travel two speed SOL To travel two speed switch horn Cabin heater Projection backside Cover upper right RB419 4476Δ Slot Starter switch RC411 5346Δ ...

Page 486: ...U20 3 U25 3 WSM Electrical system Service section V S 9 3 Around selector valve ...

Page 487: ...rmal Check or replace 2 The starter runs but the engine does not start 1 Turn On the key switch and check if fuel overflows into the tank Check visually 2 Turn On the key switch and check by hand if the fuel pump is running Replace 3 Check the fuel pump fuse for blowouts Replace 4 Check if a voltage is applied to the Fuel pump coupler 1 and 2 Repair or replace Fig 9 Fig 10 5 Disconnect the stop so...

Page 488: ...amp for blowouts Replace 3 The oil lamp does not go on 1 Check the fuse 10A for blowouts Replace 2 Check the coupler of the oil switch for disconnection Repair or replace Fig 21 3 Check if a voltage is applied to the coupler of the oil switch Repair or replace Fig 22 Fig 23 4 Disconnect and body earth the harness terminal of the oil switch and check if the lamp goes on Fig 22 5 Measure the engine ...

Page 489: ...s not function 1 Check the fuse 10A for blowouts Replace 2 Check the water temperature gauge coupler for disconnection Repair or replace 3 Check the meter side coupler for disconnection Repair or replace 4 Check if a voltage is applied to the water temperature gauge coupler Repair Fig 26 27 5 Check if the water temperature sensor is normal Repair Fig 28 8 The fuel remaining amount alarm lamp does ...

Page 490: ...pler and lever lock solenoid coupler Repair or replace Fig 34 4 Check if a voltage is applied to the 2nd speed solenoid coupler and switch coupler Replace Fig 39 Fig 40 5 Check the solenoid valve Replace 6 Check if the 2nd switch is normal Replace 3 The horn does not sound in spite of the horn switch being pressed 1 Check the fuse 10A for blowouts Replace 2 Check the harness from the grip horn swi...

Page 491: ...f the fuse 10A to see if the fuse is blown Fig 2 FUSES Replacing Fuses 1 Remove the cover of the fuse box 2 Replace the burnt out fuse with a fuse having the same capacity Fuse Capacities and Circuits No Capacity Circuit 1 15A Cabin equipment 2 15A Power source 3 5A Lever lock 4 10A Horn 5 5A Glow 6 10A Heater fan 7 20A Work lamp 8 5A Relay 9 10A High speed Alternator 10 5A Auto release 5A 10A 15A...

Page 492: ...of the battery and measure the voltage Fig 3 10 5 V or higher The battery is normal Lower than 10 5 V Charge or replace the battery 3 Automatic release relay Interchange the automatic release relay and light relay and start the engine Starting The automatic release relay is faulty Not starting The wire is broken the key switch is faulty or the starter is faulty ...

Page 493: ...ulty or the wire is broken Photo 1 5 Starter motor 1 Check the B terminal of the starter motor for looseness Check the starter coupler CN37 for disconnection Photo 2 1 2 Voltage check Fig 6 1 From the back connect the lead of a tester to the CN37 coupler terminal 1 connected to the starter motor 2 Set the key switch to the starting position and check if a voltage is applied to the CN37 coupler ter...

Page 494: ... continuity between 2 and 3 Continuity The key switch is normal No continuity The key switch is faulty 7 Fuel pump coupler 1 Measuring the voltage of the fuel pump coupler Fig 9 2 Disconnect the fuel pump coupler CN24 2 Key switch ON 2 Measure the voltage between 1 and 2 of the coupler CN24 12 V The fuel pump is faulty Other than 12 V Check for continuity Fig 10 2 Continuity check Fig 10 2 Key swi...

Page 495: ...inuity between the solenoid coupler CN36 2 and relay coupler CN339 2 3 Check for continuity between the 10A fuse and relay coupler CN338 2 9 Glow relay 1 Checking the operation of the glow relay Fig 13 1 Lightly touch the glow relay with your hand 2 Key switch ON 3 Check if the glow relay operates with a click Clicking The glow relay is normal Check the glow plug voltage Not clicking Measure the v...

Page 496: ...pection of glow plug Fig 16 2 Remove the plate between the cylinders 2 Measure the resistance of the glow plug alone 1Ω or less Normal More than 1Ω Faulty 5 Inspection of glow relay Fig 17 1 Measure the glow relay alone 2 Apply 12 V between 1 and 2 of the glow relay and check for continuity between 3 and 4 Continuity Normal No continuity Faulty 6 Measuring the voltage of the meter coupler Fig 18 2...

Page 497: ...heck for continuity between the glow relay coupler CN17 2 and coupler CN331 9 4 Check for continuity between the 5A fuse and coupler CN330 9 8 Continuity check Fig 19 2 2 Key switch OFF 2 Disconnect the coupler 1 Check for continuity between the meter coupler CN1 9 and glow control coupler CN300 3 2 Check for continuity between the coupler CN331 3 and glow relay coupler CN17 3 3 Check for continui...

Page 498: ...22 2 Disconnect the oil switch coupler CN28 1 2 Key switch ON 1 Measure the voltage of the oil switch coupler CN28 1 12 V Normal Measure the engine pressure Other than 12 V Check for continuity 2 Body earth the oil switch coupler CN28 1 Oil switch lamp Light up The oil switch is faulty Not light up The harness is broken Check for continuity 4 Continuity check Fig 23 2 Disconnect the meter coupler ...

Page 499: ...ne and measure the voltage generated during the operation of the alternator Measure the voltage between the B terminal of the alternator and the body earth If the measured voltage is about 14 V alternator generated voltage the alternator is normal If the measured voltage is equal to the battery voltage about 12 V the alternator main body or regulator is faulty 7 Inspection of alternator tester wit...

Page 500: ...er coupler Key switch OFF 1 Check for continuity between the water temperature gauge coupler CN313 1 and relay coupler CN331 6 2 Check for continuity between the meter coupler CN2 6 and relay coupler CN330 6 3 Inspection of water temperature gauge Fig 28 Performance Values in parentheses are for reference Measurement should be made with the coupler connected Temperature 7V 55f gauge Resistance Cur...

Page 501: ... V Normal Inspect the sensor Other than 12 V Measure the voltage of 2 3 Continuity check 1 Measure the voltage between the sensor coupler CN23 3 and CN23 1 2 Measure the voltage between the sensor coupler CN23 3 and body earth 4 Continuity check Fig 31 Key switch OFF Disconnect the meter coupler CN1 and CN2 1 Check for continuity between the sensor coupler CN23 2 and meter coupler CN1 11 2 Check f...

Page 502: ...olenoid valve 1 Check the lever lock coupler and lever lock switch coupler for disconnection Fig 33 Yellow for two speed Green for lever lock 2 Interchanging of lever lock coupler Fig 34 Interchange the lever lock coupler and two speed coupler Engine start While pressing the two speed pedal check if the machine runs Running The solenoid valve is faulty The lever lock switch is faulty Not running T...

Page 503: ... 2 6 Measure the voltage between the right lever lock coupler CN10 2 and body earth 12 V 1 3 and 5 are normal Inspect the solenoid valve Other than 12 V Check for continuity 2 4 and 6 Inspect the lever lock switch 4 Continuity check Fig 36 1 Check for continuity between the solenoid valve coupler CN12 2 and body earth 2 Check for continuity between the solenoid valve coupler CN12 1 and CN00 2 3 Ch...

Page 504: ... solenoid valve and two speed switch coupler Disconnect the coupler Key switch ON 1 Measure the voltage between the solenoid valve coupler CN13 1 and 2 2 Measure the voltage between the solenoid valve coupler CN13 2 and body earth 3 Measure the voltage between the two speed switch coupler CN15 1 and 2 4 Measure the voltage between the solenoid valve coupler CN15 2 and body earth 8 Continuity check...

Page 505: ... ON OFF the horn switch and check if the pointer of the tester shakes Shaking Normal Not shaking Faulty 3 Inspection of horn Fig 43 Apply 12 V between the horn terminals and check if the horn sounds Sounding Normal Not sounding Faulty 4 Continuity check Fig 44 Disconnect the coupler Key switch OFF 1 Check for continuity between the horn coupler 1 and body earth 2 Check for continuity between the h...

Page 506: ...ck Disconnect the terminal Key switch OFF Check for continuity between the working light terminal 1 and 2 3 Continuity check Disconnect each coupler Key switch OFF 1 Check for continuity between the working light terminal CN100 and CN55 coupler 1 2 Check for continuity between the working light terminal CN100 and CN55 coupler 2 3 Check for continuity between the light switch coupler CN301 5 and 10...

Page 507: ......

Page 508: ...OHIKE HIRAKATA CITY OSAKA JAPAN EDITOR CONSTRUCTION MACHINERY MANUFACTURING DEPT SERVICE SECTION HIRAKATA PLANT 1 1 1 NAKAMIYA OHIKE HIRAKATA CITY OSAKA JAPAN PHONE 81 72 840 1195 FAX 81 72 840 1195 Code No 97899 60740 Printed in Japan 0308 AK e 05 KUBOTA Corporation ...

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Kubota U20-3, Workshop Manual

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