HELI CPC 20 Manual Download Page 72

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9.Hydraulic System

Truck model

2t,2.5t

3.5t,3.8t

Main

pump

Control

valve

Lifting

cylinder

Tilting

cylinder

Model

Type

Displacement

Model

Type

Setting pressure

Flow divider

Pressure

Flow rate

Type

Bore dia.

Stroke

Type

Bore dia.

O.D. of piston rod

Stroke

CBH

-F28.2-AL

(

CBH

-F28.2(F31.5)-AL

(L)

Gear type

28.2ml/r

28.2

(31.5ml/r)

ml/r

CDB-F15

Twin-pool type with relief valve, flow divider and
tilt valve

17.5MPa

10 MPa

11 l/min

Single-action piston type with cut-off valve and
flow regulator valve

50mm

56mm

63mm

1495mm (only for lift height of 3m and standard
mast of two stage) (variable with mast type and
required lifting height)

Double action type

70mm

80mm

32mm

35mm

167mm (only for tilting angles of forward 6°and
backward 12°of mast) (variable with tilting angles
of mast)

9.1 General Description

The hydraulic system consists of main pump, control valve, lift cylinder, tilt

cylinder and hydraulic lines. The main pump is driven directly by the PTO device of

the engine.

9.2 Main Pump

The main pump is a gear pump consisting mainly of a pump body, a cover, a pair

of gears, and bushings. This pump uses pressure-balance type bearings and a special

-70-

Summary of Contents for CPC 20

Page 1: ...8t forklift truck are described in this manual in order to guide the operators to use and maintain the truck properly The rules and notices in the manual should be abided seriously by all of relative person to enable trucks in optimized working state for long period and bring the highest efficiency ...

Page 2: ...ons of Forklift Truck III Description of Main Parts of Forklift truck IV Construction Principle Adjustment and Maintenance of Forklift Truck 1 Power system 2 Clutch and clutch pedal 3 Transmission reduction gear and differential 4 Hydraulic powered transmission torque converter 5 Drive axle 6 Steering system 7 Steering axle with lateral positional cylinder 8 Brake system 9 Hydraulic system 10 Lift...

Page 3: ... when hoisting up the forklift truck 2 Storage of Forklift Truck 1 Drain off fuel completely Don t drain off the cooling water containing antifreeze and rustproof agent 2 Apply antirust to the surface of the parts not painted Apply lubrication oil to the lift chain 3 Lowing the mast to the lowest position 4 Apply the parking brake 5 Wedged up the wheels 3 Precautions before Operation 1 Don t check...

Page 4: ...nly Don t pick the loads with one fork tip 5 The starting turning driving braking and stopping of the truck should be done smoothly When steering on the humid or low friction road the truck should be decelerated 6 Travel with loads as low as possible and tilted backward 7 Be careful when traveling on a slope When climbing grade with a slope more than 10 the truck should travel forward and when des...

Page 5: ...radiator cap when the engine is warm 20 Don t adjust the control valve and relief valve at will to prevent the damage of hydraulic system and its components because of excessive pressure passing them 21 Tyres should be inflated according to the pressure valve specified in the mark plate of Tyre pressure 22 According to the measure method specified in JB T 3300 Max noise at the outboard of the truc...

Page 6: ...g system in good condition Change it once a year If the coolant is bad in less than one year change it when necessary When changing the coolant clean the interior of the cooling system The freezing point of the coolant should be at least 10 lower than the lowest environment temperature 3 Replenish the coolant with HELI exclusive one only when the engine is cool when necessary avoiding engine damag...

Page 7: ...in Place the coolant drained from the truck in a special container and deal with environmental rules 6 Oil for Forklift Truck Name Gasoline oil Diesel oil Lubricating oil Hydraulic oil Torque converter oil Gear oil Brake fluid Grease Brand for home users RQ 85 Selection according to manual for diesel engine or light diesel oil No 10 to 35 in winter and No 0 in summer in GB 252 81 Selection accordi...

Page 8: ...7 Lubrication Chart 6 ...

Page 9: ...II Specifications of Forklift Trucks See Table 1 External View of Forklift Trucks 7 L L1 B F C D 1040 1150 2 45 2 7 5 3 20 3 4 5 2100 3 8t 2195 ...

Page 10: ...9 20 19 8 9 12 1 18 18 20 19 20 19 8 9 14 7 18 23 20 19 20 19 9 8 11 3 20 15 20 19 20 19 9 8 14 20 18 20 19 20 19 10 11 3 20 15 20 19 20 19 10 14 20 16 5 20 19 20 19 11 7 15 20 15 20 19 20 19 11 20 20 20 Model Parameters Rated Capacity Load Center Standard Lift Height Free Lift Height Mast Tilt Angle Lifting Speed mm s Travel Speed km h Mechanical Hydraulic Max Drawbar Force kN Gradeability Min Tu...

Page 11: ...hang C Forks Fork Spacing adjustable Underclearance at mast Service Weight with water oil Dimensions Front Q1 Rear Q2 Length L1 Width Thickness 3646 1150 2070 4030 1600 970 970 482 494 1070 100 45 245 1020 110 3680 3752 1225 2090 4250 1700 1000 970 487 495 1070 125 45 250 1090 135 4270 3763 1225 2090 4250 1700 1000 970 498 495 1070 125 50 250 1090 135 4700 3962 1225 2090 4265 1900 1000 970 497 495...

Page 12: ...aulic Transmission Reduction Gear Differential Drive Axle Steering System Steering Axle Lifting System Operation of Brake and Clutch Pedals Clutch type truck Operation of Brake and Inching Pedals Torque converter type truck Parking Brake Operation of Accelerator Operation of Choke Hydraulic System Electric System Operating System 10 ...

Page 13: ...provided by diesel engine Xinchang A490BPG 76 Xinchang C490BPG 200 or Quanchai QC490GP DachaiCA498 97 and 3 8 ton capacity is provided by diesel engine Xinchang A4965BPG Quanchai QC495G or Dachai CA498 97 Refer to relevant manual for the details of operation and maintenances for the engine 1 2 Fuel System The fuel system is composed of a tank fuel volume sensor and fuel meter see Fig 1 1 Fig 1 1 F...

Page 14: ...f fuel into voltage See Fig 1 2 The sliding type resistor made of alloy steel wire is linked with float As the float moves up and down resistance is changed With electro magnetic fuel meter the remaining amount of fuel in the fuel tank can be read off the meter panel 1 2 3 Maintenance Once every 100 working hours it is required to maintain the fuel system according to the following methods Once ev...

Page 15: ...nce of the filter proceedings are as follows See Fig 1 3 a Once a 100 working hours it is required to remove the cartridge cover by specific tools and then take out the filter element b Once a 600 hours operation it is required to replace the filter assembly c After the re fitment of filter check it for leaks d Check overflow valve 1 for correct working Fig 1 3 Fuel filter 2 Cleaning of fuel tank ...

Page 16: ...counter clockwise the slide lead screw in the upper of the transmission to let the driving shaft go into the transmission See Fig 3 1 3 Remove six mounting bolts on the pressure plate case to cause the flywheel apart and remove the old friction piece right away 4 When a new friction piece is installed notice the hub See part 5 in Fig 2 1 with the longer spline boss being toward the transmission 5 ...

Page 17: ...e lever 10 Release bearing 11 Release bearing block 12 Bolt 13 Lock nut 14 Release yoke 15 Cover Fig 2 1 Clutch 6 After making certain that the driving shaft end has entered the middle bearing of the flywheel tighten the slide lead screw to the torque of 107 119N m 10 9 12 1kgm 7 Install the pressure plate case on the flywheel 15 ...

Page 18: ...lt a 2 Using stopper bolt a to get a pedal height from the floor of 111mm Spare travel is 30 40mm 3 Detach the spring at the end of the clutch pedal and loosen the nut b 4 Press the clutch pedal about 30 to 40mm At this time pull the release yoke forward When resistance is felt turn spherical nut b until it comes into contact with release yoke and then lock with lock nut c 5 Install the pedal spri...

Page 19: ...sists mainly of a driving shaft an output shaft a main shaft and an idler shaft each having gear s of different sizes on it The gear s can be shifted with the aid of the synchromesh mechanism installed on the main shaft by operation of the shift handle The power from the output shaft is transmitted through the reduction gear differential and half shafts to the drive shaft 3 2 1 Driving shaft and s...

Page 20: ...ger gear of the cluster gear normally meshes with the input gear and high speed gear while the smaller gear with the low speed gear The output gear normally meshes with the forward gear or reverse idler gear 3 2 3 Main shaft The high and low speed reverse and forward gears are all installed on the main shaft through needle bearings As they normally mesh with the cluster gear idler gear and input g...

Page 21: ...er bearing 21 Shim 22 Roller bearing 23 Thrust washer 24 High speed gear 25 Cluster gear 26 Low speed gear 27 Needle bearing 28 Reverse gear 29 Idler gear 30 Needle bearing 31 Idler shaft 32 Ball 33 Forward gear 34 Bearing case 35 Ball bearing 36 Output gear 37 Spacer 38 Shim 39 Nut 40 Lock washer 41 Clutch case 42 Lock nut 43 Tapered roller bearing 44 Ventilator duct 45 Breather 46 Key 47 Rotatin...

Page 22: ...ck ring Mesh sleeve 1 Block ring spline 2 Block ring 3 Spline of gear 11 4 Synchromesh cone 5 Mesh sleeve 6 Mesh sleeve spline 7 Inserter 8 Spring 9 Clutch hub 10 Shift arm 11 Constant mesh gear 12 Gear teeth of gear 11 13 Constant mesh gear 14 Gear teeth of gear 13 Fig 3 3 Synchromesh mechanism 20 ...

Page 23: ... ring spline 1 3 Inserter There are three inserters included Their center projections are fitted in the inner annular groove of the mesh sleeve spline respective two ends in three notches of the block ring These inserters are pressed against the top of mesh sleeve spline by two springs 8 to keep the block ring in position The operation of synchromesh mechanism is completed in six steps below take ...

Page 24: ...turn makes the block ring turn an angle and the side of the notches of the block ring contact with the side of inserters The mesh sleeve and the block ring turn an angle and the side on the notches of the block ring keeps in position at this time 4th Step See Fig 3 7 While the completing the 3rd step the mesh sleeve shifts over a distance of Z and the chamfer 15 of the block ring comes into contac...

Page 25: ...esh sleeve to pass through the block ring smoothly 6th Step See Fig 3 9 and Fig 3 10 While passing through the block ring the mesh sleeve shifts by a distance of Y shown in Fig 7 and the chamfers of the mesh sleeve spline 6 come into contact with the chamfer of the spline 6 See Fig 3 9 Due to the contact of chamfers the torque Tc turns the gear 11 over an angle relative to the mesh sleeve and mesh...

Page 26: ...g shaft Input gear Cluster gear High or low speed gear Synchromesh mechanism Main shaft Synchromesh mechanism Reverse or forward gear Output gear Output shaft Power flow in forward 1st speed gear position 1 2 3 4 11 10 8 9 12 16 15 17 18 5 21 Power flow in forward 2nd speed gear position 1 2 3 6 7 8 9 12 16 15 17 18 5 21 Power flow in reverse 1st speed gear position Power flow Driving shaft Output...

Page 27: ...piral bevel gear on the output shaft and a pinion shaft splined with a big spiral bevel gear Both ends of the pinion shaft are supported by tapered roller bearing Several shims are installed between the case and bearing covers to adjust the clearances between them Fig 3 12 Reduction gear differential 1 Ring gear 2 Bolt 3 Bearing seat 4 Ball bearing 5 Thrust washer 6 Tapered roller bearing 7 Bearin...

Page 28: ...shaft Ⅰ and ring gear 1 are fixed to the differential case respectively with knock pin and bolt The power from the transmission is transmitted through the reduction gear differential half shaft gear and half shaft to driving wheels 3 5 Removal of Shift Forks The figures from 3 13 to 3 20 show the removal procedures of the shift forks in the drive unit which has been removed from the truck The proc...

Page 29: ...from forward gear to backward gear or vide versa to let the front end of the shift rod leave the transmission housing Fig 3 16 5 Remove the shaft arm See Fig 3 17 6 Remove the clip ring placed at the outer end of the rotating rod with a pair of pliers SeeFig 3 18 Fig 3 15 Fig 3 16 Fig 3 17 Fig 3 18 27 ...

Page 30: ...ounting should be done in a clean place to prevent dust and foreign matters from going into the transmission 2 Check all parts for wear and damage and replace the parts excessively worn or damaged 3 As a rule each of O ring and other seals removed should be replaced with new ones The remounting procedures of the shift forks are as follows a Place the spring and the steel ball into the hole of the ...

Page 31: ...forks and the direction shift lever into the transmission See Fig 3 22 c Properly fix the shaft arm See Fig 3 23 and notice the position of the shift rod See Fig 3 24 d Two mounting bolts should be tightened to a torque of 28 4 44N m 2 9 4 5kgm before tightening the stop screw at the end of the shaft arm See Fig 3 25 Fig 3 21 Fig 3 22 Fig 3 23 Fig 3 24 Fig 3 25 29 ...

Page 32: ... torque of 3 7 23 5N m 1 4 2 4kgm See Fig 3 26 Fig 3 27 f Place the rotating rod and O ring into the transmission case See Fig 3 28 and fix them with a clip ring See Fig 3 29 g Put the transmission cover and its gasket on the case and tighten all bolts to a torque of 20 6 34 3N m 2 1 3 5kgm See Fig 3 30 Fig 3 26 Fig 3 27 Fig 3 28 Fig 3 29 Fig 3 30 30 ...

Page 33: ... as to improve the durability of friction pair 3 Both on way overrun clutches in the torque converter are used to increase the efficiency for power transmission 4 High quality of oil filters is helpful to increasing the life of the torque converter Torque converter Type Torque ratio Set pressure Charging pump Type Flow rate Transmission Type Speed ratio FWD BWD Hydraulic clutch Friction piece O D ...

Page 34: ...2 Shift arm 23 Transmission case cover 24 Shift arm shaft 25 O ring seal 26 Half round key 27 Clip ring for hole 28 29 Single row radial ball bearing 30 O ring seal 31 Clip ring 32 O ring seal 33 Idler 34 Oil filter Ⅰ 35 Output gear 36 Idler shaft 37 Single row radial ball bearing 38 Nut for bearing 39 Single row tapered roll bearing 40 O ring seal 41 Oil seal 42 Single row tapered roll bearing 43...

Page 35: ... stator that the value of output torque is more than that of input torque by the value of the reaction torque When the turbine speed keeps on increasing up to near speed of the impeller the change rate of the flow angle slows down and the value of the output torque keeps on decreasing until the liquid flows into the leaves of the stator in opposite direction When original reaction torque acts in t...

Page 36: ... clutch through a control valve to achieve the forward or the backward travel of the truck All of gears in the transmission are normally meshed Every clutch consists of four five 3 8t spacers 24 and four friction pieces 25 assembled alternately and a piston On the inner and the outer circles of the piston are seal rings for sealing the piston In the neutral the piston is still and the spacers and ...

Page 37: ...re oil Backward clutch pressure oil Lubrication oil Fig 4 3 Hydraulic clutch 1 Seal ring A 2 Bearing 3 Thrust ring B 4 Forward driving gear 5 Snap ring 6 Snap ring 7 Spring seat 8 O ring 9 Input shaft 10 Seal ring B 11 End plate 12 Snap ring A 13 Backward driving gear 14 Bearing 15 Seal ring A 16 Seal ring A 17 Seal ring A 18 Thrust ring B 19 Needle bearing 20 Snap ring A 21 Snap ring 22 Check val...

Page 38: ...ce the shock from the engagement of either clutch 4 4 4 Relief valve The relief valve connected with the transmission case keeps the oil pressure in the torque converter within 0 5 0 7MPa to prevent air corrosion 4 4 5 Inching valve It is fixed in the outside of the transmission Its spool is connected with a connection rod of the inching pedal When the pedal is stressed the spool moves to right an...

Page 39: ...l inlet cover and the dip stick are all fixed at the top of the case cover 4 6 Charging Pump See Fig 4 6 The charging pump between the torque converter and the input shaft of the transmission is a gear pump driven by the turbine shaft concluding a pair of inner meshed gears for the purpose of feeding the oil to the torque converter and the transmission 1 Snap ring 2 O ring 3 Inching valve rod 4 Sn...

Page 40: ...perate the hydraulic clutches is divided into two circuits through the pressure valve set pressure of 1 1 1 4MPa one circuit flowing to the torque converter via a relief valve set pressure of 0 5 0 7MPa and another to the Oil sealing Pump body Oil discharging hole Driven gear Driving gear Oil inlet hole O ring Torque converter oil inlet hole Relief valve Backward clutch Forward clutch Oil filter O...

Page 41: ...using corresponding clutch come to work When a clutch is at work another must stop working i e its spacers and friction pieces must be disengaged each other and be lubricated and cooled When the inching valve is operated through stressing the inching pedal a part or most of the oil in the clutches flows into the oil tank through the inching valve rod The oil circulation for the torque converter th...

Page 42: ...construction See 3 3 3 4 4 9 Towing Disabled Truck The followings should be done when the torque converter type truck to be repaired is towed by other truck 1 Remove the half shaft from the front wheel 2 Shift lever should be placed in the neutral 4 10 Positions of Connection Ports for Hydraulic Oil See Fig 4 8 40 ...

Page 43: ...eel drive type truck axle body rigidly connected to truck frame fully floated halfshaft Truck capacity Single wheel type Twin wheel type Tyre size Rim size Tyrepressure Single wheel type Single wheel type Twin wheel type Single wheel type 1 Tapered nut 2 Rim 3 Stud 4 Brake drum 5 Wheel hub 6 Operation cylinder 7 Housing 8 Clip ring for oil seal 9 Oil seal 10 Tapered roll bearing 11 Tapered roll be...

Page 44: ...ly the torque transmitted to the hubs In the inside of the hub are oil seals to prevent water and dust from entering and oil leakage The rim for 2 2 5ton truck is splited The 3 3 8 ton truck is provided with wide tyre and 2 3 8ton truck with two tyres Refer to Fig 5 2 Fig 5 2 5 2 Maintenance of Drive Axle The remounting of the hubs of the drive axle is done in following procedure 1 Grease the tape...

Page 45: ...l hub be able to be rotated freely 3 Screw down the nut for the half shaft to a torque of 96 111N m 9 8 11 3kgm 4 Screw down the wheel nut to a torque of 470 550N m 5 Screw down the nut for the brake drum to a torque of 206 225N m 43 ...

Page 46: ...of the column to the handwheel can be adjusted within 4 5 in line of driver s body The powered steering unit can transmit the pressure oil from the flow divider by metering to the steering cylinder in terms of the rotating angle of the handwheel mm mm mm mm Rear wheel steering powered 2t 2 5t 3t 3 5t BZZ1 125 Φ70 Φ50 198 Φ415 3 8t 3 3 Steering system type Truck capacity Cycloid gear type powered s...

Page 47: ...k axle 5 Spring piece 6 Joint sleeve 7 Rotor 8 Stator 9 Valve sleeve 2 Steering cylinder See Fig 6 3 The steering cylinder is of double action piston type Both ends of the piston rod are connected with steer knuckles through connection rod Left or right of the truck turning is achieved with the help of the forward or the backward travel of the piston rod driven by the pressure oil from the powered...

Page 48: ...necessary to turn the steering handwheel to right and left until it can t be turned any more to see if they are identical each other and check the operation of the steering handwheel for smoothness during above operation 2 Check the arrangement of hydraulic pipeline and turning direction of the truck for correctness 3 Put up the rear wheels and slowly turn the handwheel over again to exhaust the a...

Page 49: ...xcessive noise Oil leakage 6 3 Steering System Troubleshooting 47 Pump damaged or breaking down Flow divider blocked or damaged Hose or joint damaged or pipeline blocked Too low oil pressure from flowdivider Air in steering oil circuit Steering unit fail to recover due to spring piece damaged or elasticity insufficient Excessive inner leakage in steering cylinder Excessive flow rate for steering S...

Page 50: ... 9DT 860kPa 2 6 50 10 10PR J 5 00F 10 790kPa 7 Steering Axle with Lateral Positioned Cylinder Truck capacity Axle body type Inside wheel Outside wheel In tilting angle Out tilting angle of wheel Size of tyre Size of rim Tyre pressure Total weight Distance between pin axes Turning angle King pin 48 ...

Page 51: ...hub 11 Stop pin 12 Shim 13 Needle bearing 14 Oil seal 15 King pin 16 Knuckle 17 Steer cylinder 18 Steer axle body 19 Tie rod 20 Pin axle The steer axle is of section boxed welded construction type See Fig 7 1 It includes axle body steer cylinder tie rods and steer wheels The front and rear axles of the steer axle are pivoted in the bearing seats bolted to the rear frame thus causing 49 ...

Page 52: ...etween the upper and the lower bushes through two king pins thrust bearings and shims The king pin is locked on the steering knuckle with a lock pin Both ends of the king pin are supported by needle bearings which are pressed into the bushes There are oil seals at two faces of the needle bearing Each king pin is provided with an oil cup placed at the top of it 7 3 Rear Wheel Bearing Pre load Adjus...

Page 53: ...turns 5 Tighten the castle nut and align one of its notches with a cotter pin hole drilled in the steering knuckle 6 Again slightly knock at the hub with a wooden hammer and in this time rotate manually the hub for 3 4 turns to ensure its smooth rotation with a specified torque of 2 94 7 8N m 0 3 0 8kgm 7 If the torque value necessary to rotate the hub is more than the specified one above mentione...

Page 54: ... Master cyl bore Wheel brake type Operating cyl bore Lining size LxWxT Friction surface Inner dia of brake drum Parking brake type Front two wheel braking internal expansion hydraulic type 5 66 19 05mm Duo servo type with parking brake 28 58mm Front two wheel braking internal expansion hydraulic type with a cotter pin 52 ...

Page 55: ...alve flowing through the brake pipeline to the operating cylinder Thus each operating cylinder piston is forced outwards This brings the friction pieces on the brake shoes into contact with the brake drum and slows or stops the truck Meanwhile the cavity caused behind the piston is filled with brake fluid led through the return port and inlet port When the brake pedal is released the piston is for...

Page 56: ...ype consisting of brake shoes springs operating cylinder and adjuster and backing plates Two wheel brakes are provided o each end of the front axle The brake shoe one end of it being connected to the anchor pin and the other to the adjuster is stressed on the backing plate by the spring and spring pull rod The primary shoe is provided with the parking pull rod while the secondary shoe with the adj...

Page 57: ...body 5 Push rod for piston 6 Return spring 7 Push rod 8 Return spring 9 Adjusting lever 10 Secondary shoe 11 Clearance self adjuster 12 Spring 13 Parking cable ass y 14 Spring cover 15 Spring pull rod 16 Parking pull rod 17 Parking push rod 18 Operating cylinder 19 Return spring 20 Primary shoe 55 ...

Page 58: ...19 Clearance self adjuster 20 Pin 21 Backing plate 22 Return spring 23 Parking pull rod 24 Brake cable ass y The braking operation in the truck s forward travel is as follows see Fig 8 4 The primary and secondary shoes are respectively forced by a force equal in value and contrary in direction each other by operation of the operating cylinder to bring the friction piece in contact with the brake d...

Page 59: ...8 ton trucks by itself This adjuster however actuates only when the truck in reverse travel is braked When the brake pedal is pressed in the truck s reverse travel the brake shoe are spread As a result of this the secondary and primary shoes come into contact with the brake drum and rotate together until the upper end of the primary shoe comes into contact with the anchor pin As the secondary shoe...

Page 60: ...brake The parking brake is of mechanical internal expansion type and built in the wheel brake It shares the brake shoes and brake drum with the foot brake As the parking brake lever is pulled the parking pull rod is actuated through the brake cables See Fig 8 3E The parking pull rod pushes in turn the parking push rod to the right with the aid of the pin as a fulcrum forcing the secondary shoe aga...

Page 61: ...ight of 111mm 3 With the brake pedal pressed by the idle stroke of 30 40mm pull the push rod out until its front end comes into contact with the master cylinder piston 4 Tighten the push rod lock nut Fig 8 7 Brake pedal adjustment truck with clutch 1 1 5 m m Free travel stroke Stop bolt Pedal Oil tank 59 2 3 8t ...

Page 62: ...oosen the push rod and interlocking bolt 2 Adjust the pedal to the height of 111mm with the stopper bolt 3 Adjust the left side pedal inching pedal for 2 10mm idle travel with the stud 4 Press the right side pedal for 60mm and adjust the stud length until the front end of the push rod get in contact with the master cylinder piston then lock with a lock nut 5 Adjust the interlocking bolt until its ...

Page 63: ... mainly for 2 ton truck s brake the 3 3 8 ton trucks brake is similar to it in general 8 8 1 Wheel brake disassembly 1 Remove the hold down spring of secondary shoe the adjusting lever and push rod and its return spring See Fig 8 9 2 Remove two shoe return springs See Fig 8 10 3 Remove three hold down springs See Fig 8 11 Fig 8 9 Fig 8 10 Fig 8 11 61 ...

Page 64: ...olts and detach the operating cylinder from the backing plate See Fig 8 13 6 Remove the E retainer for securing the parking brake cable to the backing plate Remove the backing plate mounting bolts and detach the backing plate from the drive axle body See Fig 8 14 7 Remove the operating cylinder boot and push all parts out of the cylinder See Fig 8 15 Fig 8 12 Fig 8 13 Fig 8 14 Fig 8 15 62 ...

Page 65: ...r 2 ton trucks 58mm for 3 3 8 ton trucks 4 Check the friction piece for thickness to see if it is excessively worn If necessary replace it Specified thickness 7 2mm for 2 ton trucks 8 0mm for ton trucks Minimum thickness 5 0mm for 2 ton trucks 6 0mm for ton trucks 5 Check the inner surface of brake drum for damage and excessive wear If necessary replace it Standard inner dia of drum 310mm for 2 to...

Page 66: ... 3 Free length L 86mm for 2 ton trucks L 121mm for ton trucks Setting length L 97mm for 2 ton trucks L 137mm for ton trucks Setting load 153N for 2 ton trucks 71 5N for ton trucks 9 Check the ratchet pawl spring for free length and setting load See Fig 8 20 Setting load 14 7N for ton trucks 10 Check the adjuster to see if it is damaged or in good condition and the contact of the adjuster lever for...

Page 67: ... 5N m for ton trucks 3 Install the backing plate on the front axle Torque moment for bolts 120 140N m 4 Apply No 2 calcium base grease on the a b c d and e points indicated in Fig 8 21and Fig 8 22 with care not to contaminate the friction piece with grease a Backing plate bearing surface b Anchor pin parking puller c Anchor pin d Screws of the adjuster and other rotating part e Contact surfaces be...

Page 68: ... seat settles snugly in the shoe and the adjusting lever holes See Fig 8 23 7 Put the spring on the parking push rod and then install the rod on the shoe 8 Install the shoe guide plate on the anchor pin and install the shoe return spring See Fig 8 24 9 Install the clearance self adjuster adjuster spring and push rod and its return spring See Fig 8 25 Pay attention to the following points a Adjuste...

Page 69: ...perating cylinder 11 Measure the inner dia of drum Adjust the adjuster to obtain the difference needed between the drum inner diameter and the friction piece outer diameter Specified difference 0 8 0 9mm for 2 ton trucks 0 5 0 8mm for ton trucks 8 9 Operation Test to Clearance Self adjuster 1 Make the brake shoe diameter approach the specified mounting size and pull the adjusting lever with your f...

Page 70: ...eck to see if the adjusting lever and adjuster gear are correctly arranged See Fig 8 26 for 2 ton trucks and Fig 8 27 for ton trucks If necessary replace them Also check if the adjusting lever is in contact with the gear c Check the push rod return spring and adjuster spring for deterioration and also check the adjuster gear for rotating condition and undue wear or damage of the meshing section 3 ...

Page 71: ...or loose bolts 3 Deformed shoe or incorrect installation 4 Worn friction piece 5 Loose wheel bearing 1 Oil contaminated friction piece 2 Maladjustment of brake shoe clearance 3 Malfunctioning operating cylinder 4 Shoe return spring deteriorated 5 Deflected drum 1 Brake fluid leaks from system 2 Maladjustment of brake shoe clearance 3 Air mixed in brake system 4 Maladjustment of brake pedal Repair ...

Page 72: ... and flow regulator valve 50mm 56mm 63mm 1495mm only for lift height of 3m and standard mast of two stage variable with mast type and required lifting height Double action type 70mm 80mm 32mm 35mm 167mm only for tilting angles of forward 6 and backward 12 of mast variable with tilting angles of mast 9 1 General Description The hydraulic system consists of main pump control valve lift cylinder tilt...

Page 73: ...al is press fitted into the pump body to provide oil tightness performance Oil tightness between the pump body and the pump cover is secured with a packing with special shape 9 3 Control Valve Divider See Fig 9 1 The control valve 2 spool type consists of four valve housings two spools one relief valve and one flow divider The four valve housings are assembled together with three stud bolts and nu...

Page 74: ... this time the spool is pushed in to close the mid passage This causes the oil from the main oil inlet to push up the inlet check valve and to flow into the port B The return oil from the port A flows through the low pressure passage to the tank and the spool is restored to its neutral position by the return spring Inlet check valve Main oil inlet Port A Return spring Spool Low pressure passage Mi...

Page 75: ...eck valve and flows into the port A The return oil from the port B flows through the low pressure passage to the tank The spool can be restored to its neutral position by return spring 9 3 2 Relief valve and flow divider See Fig 9 5 Fig 9 5 Oil return port Oil inlet port Main safe valve Flow divider To steering unit 73 ...

Page 76: ...assage If the oil pressure is higher than the spring force the poppet N moves right causing the high pressure oil to flow directly to the low pressure passage via Chamber T and keeping the pressure of the power steering system unvaried The setting pressure is adjusted by adjusting the screw K Poppet L is a balance type spool valve and may move right of left according to the variety of the oil flow...

Page 77: ...engine stops no pressure oil moves the tilt lock valve the port A can t connect the low pressure tank and the tilt cylinder and the mast can t be tilted forward 9 4 Hydraulic System See Fig 9 7 The oil from the main pump cones to the control valve first and there is divided by the flow divider into two parts one being sent to lift cylinder or tilt cylinder and another to the power steering unit in...

Page 78: ...il reaches the front or rear chamber of the cylinder and pushes the piston forward or backward The oil pushed out by the piston returns to the oil tank through the control valve and the mast then tilts forward or backward Fig 9 7 Hydraulic oil circuit T C Tilt cylinder L C Lift cylinder C V Control valve F D Flow divider F V Flow regulator valve C O V Cut off valve P C Power steering cylinder P S ...

Page 79: ...n rod with castled nut and cotter pin is fitted with a Yx type seal snap ring and packing on its outer periphery It moves up along the inner surface of the cylinder by high pressure oil from the cylinder bottom With press fitted bushing and dust seal the cylinder cap is screwed into the cylinder body The bushing supports the piston rod and the dust seal keeps dust off The stroke of the piston can ...

Page 80: ...Set screw 16 Knock out pin 25 Chain wheel 26 Plug 27 Stop plate 28 Set screw 29 Screw plug At the bottom of the lift cylinder is a cut off valve See Fig 9 9 which operates when the high pressure hose bursts for any reason to prevent the load from dropping down abruptly The oil from the lift cylinder flows through small holes in the circumference of the cut off valve spool and produce a pressure di...

Page 81: ...ate Fig 9 9 9 6 Flow Regulator Valve The flow regulator valve located in the lift cylinder circuit to limit the descending speed of loaded forks has the construction as shown in Fig 9 10 When the lift spool is placed in the lift position the oil from the control valve flows through the oil chambers A and B oil holes C D E and F and the chamber G to the lift cylinder without any regulation When the...

Page 82: ...iston piston rod cylinder body cylinder base guide sleeve and seals The piston welded to the piston rod is fitted with two Yx rings and one wear ring on its circumference A bushing press fitted to the inner side of the guide sleeve supports the piston rod The guide sleeve is fitted with dust seal snap ring Yx ring and O ring to prevent oil leakage and keep dust off Fitted with them the guide sleev...

Page 83: ...e front cover 7 and 8 9 10 11 4 Remove bearings 3 4 and gears 5 6 out of pump body 2 If it is difficult to remove the bearings and gears press a gear in to solve it For the convenience of checking it is recommended to place the disassembled parts in this order as shown in Fig 9 18 9 19 9 8 2 Inspection and repair The disassembled parts except rubber parts should be washed with light oil These disa...

Page 84: ...craping trace becomes longer than 1 2 long of the inner periphery replace the pump body 2 Bushing inspection See Fig 9 13 9 14 Fig 9 13 Fig 9 14 It is desired as an ideal condition that the inner sliding surface of the bushing is smooth and about the half portion toward the inlet side presents lustrous contact surface If any one of the following conditions is found replace the bushing a The whole ...

Page 85: ...xcessively replace the gears as well as the bushings The service limit of the bushing is as follows See Fig 9 14 Inner diameter 19 123mm Overall length 26 411mm 3 Gear inspection As long as clean hydraulic oil is used the gear shaft and gear face will not get damaged If the gear shaft and gear face feel rough with your nail or flaws in gear face are found or the gear surface is very unevenly worn ...

Page 86: ...e reassembling the pump c Packing rings 10 and 11 Check for wear or breakage 9 8 3 Reassembly See Fig 9 17 Fig 9 17 1 Clean disassembled parts 2 Apply a thin coat of clean grease on the lips of packing ring 8 9 10 11 and 14 3 Put pump body 2 on a plain stand with cover 1 upward Put clean hydraulic oil on the inner surface of the pump body 4 Hold bushings 3 and 4 properly in the pump body Notice no...

Page 87: ...cking rings 8 9 10 and 11 11 Install the rear cover 1 12 Install the lock washer 13 and bolts 12 and tighten up the bolts with a 0 26 0 25 torque of 47 N m 4 7 kgm 0 0 Check the gear pump for completeness and correctness and then clamp down its driving shaft with a vice to check the pump to see if it is easy to be rotated If it is hard to be rotated recheck the pump Check the gear pump for the ass...

Page 88: ... to 2 to 3MPa 2 or 20 to 30kg cm and run the pump for five minutes Then increase the pressure to maximum with loading the relief valve Each circuit works for five minutes and then renew or clean the element of return filter During the increase of the pressure observe the change of oil temperature and pump body surface temperature and working voice If the oil temperature or pump body surface temper...

Page 89: ...Oil tank Tilt cylinder right Main pump Steering cylinder To flow regulator Control valve Steering unit Tilt cylinder left Fig 9 18 Hydraulic pipeline sketch 87 ...

Page 90: ...al temperature Concentric mounted gear pump Find out causes and correct them Replace Lower oil level in oil tank Blocked suction pipeline or oil ilter f Worn bushing 3 and 4 or broken down packing 9 10 or 11 Misadjusted relief valve Air entering into the pump Twisted suction nose or caviation incurred by oil filter blocked Air entering in resulting from loose suction connections Too high oil stick...

Page 91: ...nner mast Cross section of outer mast Roller Main roller 1 Φ 119 2 3 8t Roller 2 Φ 109 7 Retaining roller Φ 80 Side roller Ⅰ Φ 80 Side roller Ⅱ Φ58 Side roller Φ91 5 3 3 8t Lifting chain ISO LH 1234 2t 2 5t LH 1623 3t LH 1634 3 5t 3 8t Lifting system of the fork mast Hydraulic Fork spacing adjustment Manual Φ 123 3 8t Φ 123 Φ 46 3 8t Φ 50 89 2 3 5t 3 8t ...

Page 92: ...nd side rollers to sustain the longitudinal and transverse load the inner mast can operate smoothly 10 3 Carriage The carriage is a welded part It moves up and down smoothly along the channel of the inner mast with main rollers and clearance adjustable side rollers sustaining the longitudinal and transverse loads For the carriage for 2 to 3 5ton trucks three groups of main rollers and two groups o...

Page 93: ...oil return pipe and the clearance between the sealing parts and other parts if the cylinder is not used for a long time And thus the piston rod and inside of the cylinder barrel will be corroded and the exterior of the cylinder will become rusty Once the cylinder gets rusty it will be no longer serviceable Rust protection and maintenance measures 1 Rust protection of the piston rod exposed outside...

Page 94: ...er and etc 4 Lighting and signal devices They include some lighting and signal devices horn and buzzer Front big lamp 35W Front combination lamp for turning width indicating 21W 8W Rear combination lamp for width indicating braking reversing 8W white 21W red 21W red 11 2 Description on Operation of Meters 1 Preheating starting switch Turn the switch to 1st step to turn on meters and ignition coil ...

Page 95: ...everse of the truck is required position the change over lever to the reverse step the reverse lamp lights up and the back buzzer sounds 7 Displaying for charging signal When right turning the key switch to 1st step the charging indicator lights up and after the engine starts it goes out automatically If it lights up during the engine running this indicates the charging circuit goes out of order I...

Page 96: ...ed to indicate 60 to 80 the green area to indicate 80 to 110 normal working temperature of the engine and the red area to indicate 110 to 145 When the meter pointer reach at the red area stop the truck until it returns to the green area 11 Hour meter It is used to indicate the sum of working hours of the engine 94 ...

Page 97: ...Fig 11 1 Electric system 95 ...

Page 98: ... 96 ...

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