Chevrolet DB90 Series Service Manual Download Page 2

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1972

CHEVROLET

HEAVY DUTY TRUCK

(SERIES 70, 80, and 90)

SHOP MANUAL

SUPPLEMENT

FOREWORD

This supplement has been prepared for use with the

1970 Heavy Duty Truck Shop Manual and the 1971
Heavy Duty Truck Shop Manual Supplement. It covers

additional service information peculiar to 1972 Chev
rolet Heavy Duty Trucks.

Summaries of new or revised Specifications for

truck components are included at the end of each major

section.

All information, illustrations and specifications

contained in this literature are based on the latest prod

uct  information  available  at  the  time  of  publication
approval.  The  right  is  reserved  to  make  changes  at  any
time  without  notice.

CHEVROLET MOTOR DIVISION

G e n e ra l M otors C o rporation

D ETR O IT, M IC H IG A N

SERVICE SECTION INDEX

6 C

6D
6K

6 M

General Motors Corporation

Printed in U .S .A .

LUBRICATION

CABS AND

BODY MOUNTINGS

FRAME

FRONT SUSPENSION

REAR SUSPENSION

.BRAKES

GASOLINE ENGINES

SERIES 5 ^ and 71

DIESEL ENGINES

ENGINE MOUNTINGS

ENGINE COOLING SYSTEM

ENGINE FUEL SY5TEM

AIR COMPRESSOR

AND GOVERNOR

ENGINE ELECTRICAL

TRANSMISSIONS

AND CLUTCHES

FUEL TANK & EXHAUST

STEERING SYSTEM

WHEELS & TIRES

SHEET METAL

CHASSIS ELECTRICAL

AND INSTRUMENTS

RADIATOR AND

SURGE TANK

SPECIAL TOOLS

; :'^Vv

;v*' ■

Summary of Contents for DB90 Series

Page 1: ...HEAVY DUTY TRUCK SUPPLEMENT...

Page 2: ...test prod uct information available at the time of publication approval The right is reserved to make changes at any time without notice CHEVROLET MOTOR DIVISION G eneral Motors Corporation DETROIT M...

Page 3: ...plementary information before servicing any unit or system on 70 thru 90 Series trucks SECTION INDEX SECTION PAGE 0 Lubrication 1 1 Cab and Body Mountings 13 2 Fram e 21 3 Front Suspension 23 4 Rear S...

Page 4: ...2 13 2 14 2 F070 F090 F120 17121 17221 18121 18221 19221 285V 282V 387V 5652 5752C WIT40 AT540 TV70 6V 53N 14 2 F070 F090 F120 17221 19121 19221 5752C MT41 WM80 401M 13 2 13 2 F090 F120 34DSC SLHD 56...

Page 5: ...90 F120 18221 19221 408V FB90 8V 903 14 2 F120 19121 RT910 FC90 NHCT270 NTC335 14 2 14 2 15 2 2 F120 19121 R170 RT910 RT09513 FH90 8V 71N 14 2 151 2 2 F120 19121 R170 RT910 RT09513 FI90 6 71N 14 2 F12...

Page 6: ...6 71 6 cyl In Line Detroit Diesel M V 6 Gasoline N 6 cyl 230 or 250 Cummins Diesel P 12V 71 12 cyl V Detroit Diesel V 6V 53 6 cyl V Detroit Diesel W 6V 71 6 cyl V Detroit Diesel ASSY PLANT CODE V Po n...

Page 7: ...e conditions for MT Series only Drain while fluid is at operating temperature 160 F minimum MT Series Transm ission 1 Remove bolt nut and strap which secure filter cover to oil pan 2 Carefully remove...

Page 8: ...Sec 0 2 LUBRICATION Figure 1 Lubrication Chart Conventional Cab M odels...

Page 9: ...in and refill GO 12 000 21 Transm ission Spicer d ES 6 000 Drain and refill ES 12 000 21 Transmission Auxiliary d ES 6 000 Drain and refill ES 12 000 21 Transmission Automatic d S19 6 000 Drain and re...

Page 10: ...Sec 0 4 LUBRICATION CHEVROLET SERIES 70 90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT...

Page 11: ...ttery Terminals Keep coated S3 6 000 17 Transmission Shift Rod U Joint 1 fitting each joint MPG 6 000 18 Clutch R elease Cross Shaft 1 fitting each e n d MPG 6 000 19 Power Steering Cylinder Ends d 2...

Page 12: ...Sec 0 6 LUBRICATION CHEVROLET SERIES 70 90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT...

Page 13: ...ry Trans Shift Levers d 2 fittings 6 000 24 Transm ission Shift Rod U Joints d 1 fitting each joint MPG 6 000 25 Hand Brake B ell Crank d 1 fitting MPG 6 000 26 Steering Gear Housing To level of fille...

Page 14: ...Sec 0 8 LUBRICATION CHEVROLET SERIES 70 90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT...

Page 15: ...fitting MPG 6 000 19 Prop Shaft U J o ln ts 1 fitting each joint MPG 6 000 20 Steering Gear H ousing To level of filler plug Remove rubber c o v e r SG 6 000 21 Battery Term inals Post T y p e Keep co...

Page 16: ...ing each 6 000 6 Brake Shoe Roller Pins c Apply 20 000 7 Wheel Bearings d Hand pack or use lubricator MPG 20 000 a 8 Axle Shift Unit 2 or 3 Speed c To level of filler plug S7 12 000 9 Equalizer Beam R...

Page 17: ...ilter c Clean and in s ta ll 6 000 7 Distributor c Y 2 turn of cam lubricator 12 000 a Breaker pivot 1 d ro p 6 000 Rotor felt 4 d r o p s 6 000 No lubrication required 9 Starter See instructions E 10...

Page 18: ...h are intended for Service Designations MS and DM SE CC New A P I Designation NOTE Supplement 1 engine oils based upon now obsoleted MIL L 2104A have been super seded by MIL L 2104B engine oils Howeve...

Page 19: ...oosening it with a 5 16 inch hex wrench The bolt fore and aft adjustment is ob tained by use of shim spacers located between the bolt washer and the base 8 After proper adjustments have been com plete...

Page 20: ...t with One Piece Cushion Cab rear mounts are of the sem i sheer type and are serviced only as an assem bly The sem i sheer type rear mounts are bolted to the cab sill and the frame side rail as shown...

Page 21: ...able for service WIPER BLADE REPLACEMENT Refer to Figure 8 1 Hold fillister head screw with screwdriver and remove lock nut Remove screw which is threaded into wiper arm and remove blade Re verse proc...

Page 22: ...ecial retaining nut at the transm ission shaft forward of cowl MOTOR REPAIR Key numbers in text refer to figure 9 For all internal repairs it is necessary to remove valve head assem bly 26 If necessar...

Page 23: ...14 12 Gear 13 Body 14 Gasket 15 End Plate 16 Screw 17 Spacer 18 Nut 19 Screw 20 Retainer 21 Felt Washer 22 Valve Stop Unit Assy 23 Piston Packing 24 Gear Rack A ssy 21 20 19 25 Piston 26 Valve Head A...

Page 24: ...be withdrawn from cylinder body 13 NOTE If necessary tapered motor shaft 8 can be pressed from gear 12 and bushings 10 by removing nut 18 and spacer 17 Note position of shaft arm and teeth of gear ar...

Page 25: ...d fittings kinked tubing or leaks Make sure that all connections are tight NOTE A quick method to check for leaks is to disconnect the line stop up oneendandblow smoke through the other this will reve...

Page 26: ...YS WEAR HEAVY TYPE GLOVES TO PREVENT INJURY WHEN HANDLING GLASS IMPORTANT NEVER SLEEP IN CAB UNLESS ADEQUATE VENTILATION IS PROVIDED IMPORTANT DO NOT DRILL ADDITIONAL HOLES IN FRAME DO NOT WELD HEAT T...

Page 27: ...weld reinforcements across the frame flanges 9 Do not weld within inch of the edge of a frame flange 10 Remove all notches or weld build ups from flange edge when repairing a broken frame 11 Do not we...

Page 28: ...ompany Republic 50 Republic Steel Company Yoloy S Youngstown Steel Tube Company Man Ten U S Steel Medium Manganese Bethlehem Steel Company Tri Ten E U S Steel HIGH PERFORMANCE STEEL Trade Name Source...

Page 29: ...V s V s to 14 F 120 39 27 45 5 45 6 15 TV70 1 30 30 1 30 30 1 15 30 Vi6 to V s a to 4 F 070 39 27 45 7 7 TM80 0 15 30 0 15 30 1 15 30 Vi6 to V s V s to F 090 39 27 45 5 45 6 15 0 15 30 0 15 30 1 15 30...

Page 30: ...ring Knuckle Spindle 2 Steering Knuckle Bushing 3 Kingpin Bushing Upper 4 Kingpin 5 Dust Cap 6 Kingpin Nut 7 Cotter Pin 8 Gasket 9 Lube Fitting 10 Washers or Shims 11 Axle Center 12 Stop Bolt and Lock...

Page 31: ...wo draw keys by placing drift against sm all end of each key NOTE Keys were originally installed from opposite sides of center 6 With axle components properly supported drive the kingpin downward usin...

Page 32: ...be recessed into axle center hole no less than 1 8 inch or more than 3 16 inch NOTE The short key is installed in upper hole and the long key in lower hole IMPORTANT DO NOT INSTALL BOTH KEYS FROM SAME...

Page 33: ...2452871 O D 435 437 O D 498 1 In O o USING POINTED PUNCH STAKE HOLE OVER IN THREE PLACES Select the proper size draw key to obtain the following condition when fully installed Large end of key must be...

Page 34: ...8 1 990 2 010 2 7 32 2 9 32 1 940 I D When Installed 1 2496 1 2526 1 4365 1 4375 1 607 1 610 1 7940 1 7970 1 827 1 830 1 607 1 610 1 999 2 002 STEERING KNUCKLE TO AXLE CENTER CLEARANCE 0 005 0 004 0...

Page 35: ...N When replacing shock ab sorbers check the model number stamped on the unit to make sure it is the same model as the one removed Refer to Speci fications for shock absorber nut torque CAUTION U bolts...

Page 36: ...retightened to torque listed in Specifications after 500 m iles when new or after spring repair or replacement NUTS 40 50 FT LBS TORQUE REAR BRACKET SHACKLE LINK NUTS 110 1 30 FT LBS TORQUE SPRING RE...

Page 37: ...0 FRONT SPRING BRACKET TO All Models except TM80 50 60 FRAME BOLT NUT TM80 35 45 FRONT SPRINGS REAR BRACKET HM80 HV70 40 50 TO FRAME BOLT NUT JM80 JV70 50 60 TM80 35 45 TV70 WM80 55 75 WV70 30 40 HM80...

Page 38: ...w diameter with two raised lines indi cating ADD and FULL as shown in figure 13 for oil level reference A 4 3 8 window diameter to be used mainly on the FL901 front axle It will have a vent hole in th...

Page 39: ...D IFFER EN TIA L CA RRIER TO HOUSING Eaton W 13 Cap Screw 75 85 5 e ll Cap Screw 160 175 Vs IS Stud Nut 220 240 Rockwell V i 20 Stud Nut 92 118 5 s 18 Stud Nut 185 235 Corporation 7 i6 20 Cap Screw 7...

Page 40: ...shifted into LOW range with engine running Engage clutch and transm ission to be sure axle has completed shift into LOW range Apply parking brake place transm ission in neutral and shut off engine Whe...

Page 41: ...rame Bracket 7 Torque Rod 8 Torque Rod Frame Bracket 9 Rebound Bolt 10 Equalizer Beam 11 Saddle Cup 12 Beam Center Bushing 13 Spring and Saddle Assembly 14 Top Pad 15 Saddle Bolts t 9046 Figure 1 Tand...

Page 42: ...MS Control arms as shown in figure 4 are equip ped with replaceable rubber bushings which attach rear axle to frame brackets Control arms are secured to axles by U bolts and anchor plates A Delrin lin...

Page 43: ...and U bolt nuts 6 Tighten both control arm setscrew s ap proximately equal distance and torque to Speci fications 7 Final torque control arm pivot bolts and U bolt nuts to Specifications HM8721B SUSPE...

Page 44: ...ting bolts and remove bracket INSTALLATION 1 Replace any damaged or worn shackle pin or bracket and bolt bracket to frame Torque bolts to Specifications listed at end of this section 2 Align spring ey...

Page 45: ...ve pins attaching spring ends to shac kles as previously directed under Rear Spring Shackle Pin or Bracket Replacement 3 Remove nuts and washers from spring U bolts remove U bolts bottom plate and U b...

Page 46: ...inserted through one side of each radius rod yoke engaging a flat on head of pin Radius rod front bracket eye is integral with rear spring front shackle bracket fig 7 Radius rod rear bracket eye is a...

Page 47: ...UE TYPE OF TORQUE PART FT LBS REYCO SUSPENSION PART FT LBS Nut 190 210 Spring Hanger Bracket To Frame ALL Nut 90 110 Nut 320 350 Spring Center Bolt 65 75 Nut 150 200 Spring to Axle U Bolt Nut 190 210...

Page 48: ...are now in serted in each end of the trunnion see fig 1 This feature helps retain lubricant at the outer bearing area to prevent a drainback of warm more liquid lubricant to the center of the trunnio...

Page 49: ...r pressure to relieve any air lock inside the joint which would prevent lubricant from reaching the bearing area UNIVERSAL JOINTS 58 AND 68WB The Delta Wing bearing of the 58WB and 68WB type universal...

Page 50: ...TE H E H I H N 90 E 18 19000 68WB 68WB 68WB HI 90 E 19000 R 170 1700 1700 1700 HN 90 E 19000 R 170 1700 1700 1700 JE 90 E 34D3 SLHD 68WB 68WB 68WB 68WB JI 90 E 34D3 68WB 68WB 68WB 68WB JI 90 SLHD SQH...

Page 51: ...brake systems or parts ________________________________ BRAKE PEDAL PUSH ROD ADJUSTMENT IMPORTANT If any doubt exists relative to push rod adjustment remember it is better to have push rod too short t...

Page 52: ...allation 1 Position m aster cylinder assem bly at sup port bracket and guide push rods into pistons Make certain that push rod boot is in place on push rod and on support bracket Attach cylinder with...

Page 53: ...length of time the exhaust valve remains open and the amount of water and contaminants ejected depends upon the sump pressure and the reservoir pressure drop that occurs each time air is used from th...

Page 54: ...3 R oller 4 Wedge Retainer W asher 5 Wedge Return Spring 6 Return Spring Washer 7 Cotter Pin 8 Wedge 3 Plunger Guide Wherever the term plunger guide or guide is used it should be changed to read adju...

Page 55: ...re the sam e except reference to the retaining washer is to be removed See figure 6 BREATHER AND FILTER ASSEMBLIES Figures 7 and 8 illustrate three different breather and filter assem blies Figure 7 l...

Page 56: ...mber 3 600 Hrs lOO 000 M iles 1 Year Remove disassemble clean inspect Anchorlok Brake Chamber Stopmaster Brake Chamber 2 Months 25 000 Miles Check operation and air lines Fail Safe Brake Chamber Annua...

Page 57: ...HV 70 JM 80 JV70 TE MB MC JB HC HE HH HI HN JC JE JH Jl JN MH 90 and all 90 TV 70 RM WM TM 80 WV 70 HM 80 REAR BRAKES SIZE TYPE M O D ELS 15x6 15x7 15x7 16 1 2x7 Wedge Wedge Cam Cam HM JM80 HV 70 JV...

Page 58: ...S The air com pressor is the source of supply for the vehicle braking system Faulty operation of the com pressor will result in improper function of brakes CHEVROLET SERIES 70 90 HEAVY DUTY TRUCK SHOP...

Page 59: ...valve partially plugged Blow by close to capacity of valves Check the valves Tester hose kinked or blocked Reposition or clean hose Crankcase not sealed properly Check tester plugs and other seal off...

Page 60: ...ion valves which are screwed into threaded ports in cylinder heads NOTE One valve is used in each cylinder head on V6 engines and two valves are used in each cylinder head on V8 engines Use socket wre...

Page 61: ...pulley or hub onto front end of crankshaft Assem ble special installer typically shown in figure 5 and turn nut with wrench to force pulley firmly into place on crankshaft 4 Remove installer then refe...

Page 62: ...enly to 10 to 15 foot pounds torque Overtightening the bolts will distort the oil pan flange IMPORTANT Make sure the sleeves 18 on oil inlet tube assem bly 6 are in good condition and not distorted or...

Page 63: ...ve socket in pump shaft 2 Set oil pump assembly in position at cylin der block and turn pump as necessary to engage the pump drive shaft with drive socket at distrib utor 3 Align mounting bolt holes i...

Page 64: ...ing cap shaded area in figure 7 Oil the cap bolt threads and washers with S A E 10 engine oil Insert 5 8 11 bolts with washers into holes in bearing cap and start bolts into threads but do not tighten...

Page 65: ...At engine idle speed with vacuum line disconnected and plugged No load speed is approximately 300 rpm higher than full load speed V8 GASOLINE ENGINE TUNE UP CHART ENGINE MODEL 637 TIMING POINTER T 903...

Page 66: ...n 85 105 Oil Filter Housing to Cylinder Block Bolt 26 36 Oil Filter Center Stud B o l t 40 50 Oil Pan to Cylinder Block B o l t 10 15 Oil Pan Drain Plug 20 30 Valve Lifter Cover Bolt 4 5 Rocker Arm Co...

Page 67: ...icable to engines used in vehicles covered by this supplement except for subjects indicated by the Index above The in formation under each of the subjects either supplements or replaces information in...

Page 68: ...ntinue to tighten these bolts as the head is lowered into position on the cylinder block 6 Install the balance of the bolts and stud nuts and tighten them according to the procedure out lined in Servi...

Page 69: ...attaching bolts and withdraw the governor high speed spring retainer cover fig 3 2 Loosen lock nut and back out the buffer screw IMPORTANT The buffer screw must be ad justed with caution since it con...

Page 70: ...g cover and gasket being sure that throttle shaft pin engages differential lever fork and that the stop lever will release the control rack to NO FUEL position Install four cover screw s and washers b...

Page 71: ...K CONTROL LEVER SCREWS 53 AND 71 DIESEL ENGINES Overtightening of the injector rack control lever screw s can cause damage to the injector control tube The recommended torque for these screw s is 24 t...

Page 72: ...with the proper timing mark on the crankshaft gear The crankshaft gear is stamped IL A and A VR on the left and right side of the triangle timing mark fig 1 For Standard Timing the triangle on the cra...

Page 73: ...e crankshaft opposite the direction of rotation between 1 16 and 1 8 of a turn 6 Select a dial indicator with 0 001 gradu ations and with a spindle movement of at least 1 inch Use suitable mounting at...

Page 74: ...with particular engine as shown on En gine Timing Chart fig 7 19 After completing the timing check remove the dial indicator Remove the shipping caps from the injector and install the injector fuel li...

Page 75: ...ck of power uneven running excessive vi bration stalling at idle speed and hard starting may be caused by either low compression faulty injection in one or more cylinders or lack of suf ficient air Si...

Page 76: ...ure on the other cylinders until the faulty one has been located 6 Provided the injector operating mechanism of the faulty cylinder is functioning satisfactorily remove the fuel injector and install a...

Page 77: ...ral causes a Piston rings may be stuck or broken To determine the condition of the rings remove the air box cover and inspect them by pressing on the com pression rings with a blunt tool fig 15 A brok...

Page 78: ...l oil Install the shell and element 3 Remove and fill the secondary fuel filter shell and element with fuel oil as in Step 2 4 Start the engine Check the filter and strain er for leaks NOTE In som e i...

Page 79: ...to Fuel P ressure chart opposite Uneven running excessive vibration stalling when idling and a loss of power may be caused by an insufficient fuel supply to injectors due to one of the following cond...

Page 80: ...late gaskets 9 Excessive exhaust back pressure ENGINE OIL PRESSURE TEST Refer to Figure 18 To check operating oil pressure connect the pressure gauge to the oil gallery or into oil line from gallery t...

Page 81: ...cleaner An obstruction in the air inlet system or dirty or damaged air cleaners will result in a high blower inlet restriction The air inlet restriction may be checked with a water manometer connected...

Page 82: ...er temperatures The maximum ex haust back pressure no load is shown in the fol lowing chart NOTE Due to variations in exhaust system s horizontal or vertical stacks the above chart is typical EXHAUST...

Page 83: ...r 1 psi m 27 7 water 1 psi u 2 036 mercury OIL FUEL AND COOLANT LEAK TROUBLESHOOTING A Troubleshooting procedure to be used to disgnose leaks within the engine fuel or cooling system is as follows HEI...

Page 84: ...ving cylinder heads for leakage c Cylinder Head may be checked as previ ously described d Engine Block may cause leakage of oil in water if cracked between pressurized oil passage and water jacket Eng...

Page 85: ...f an in jector spray tip should be done with a brass wire buffing wheel and not a steel wire wheel The best motor speed for maximum brush life and the best polishing effect is 3 000 rpm The hardness o...

Page 86: ...h 1 484 dimension instead of J 1853 as used on all other injectors Note 1 No load governed speed is approximately 150 RPM more than full load speed 8V 71N 8V 71NE 12V 71 ENGINE TYPE 2 Stroke Cycle FIR...

Page 87: ...ts and Washers 11 Bolt Lock Wire 12 Bracket to Plate Bolt 13 Lock Wire 14 Bracket at Crossmember T 9063 torque 60 70 ft lbs 6 torque 70 80 ft lbs 1 Support Bolts 6 Mounting Bolt w Flat 2 Mounting Bolt...

Page 88: ...gine Bracket Assy Welded 2 Bolts with Plain Washers 3 Mounting Bolt Nuts 4 Plain Washers 5 Insulator 6 Mounting Bolts 7 Plate 8 Frame Member T 9067 V torque 220 240 ft lbs FRONT CROSSMEMBER UPPER AND...

Page 89: ...bracket and mounting assem bly to crossm em ber or engine then remove bracket and mounting assem bly 3 Separate and inspect mounting components Replace as required NOTE On some vehicles if engine fron...

Page 90: ...f trans m ission it will be necessary to disconnect attach ing parts to permit rear of transm ission to be raised for engine rear mounting replacement Re fer to applicable portion of TRANSMISSION ON V...

Page 91: ...M BOLT FT LBS a GM 300 M BOLT FT LBS NUT TORQUE FT LBS 1 4 20 28 5 16 18 24 3 8 16 24 7 16 14 20 1 2 13 16 9 16 12 18 5 8 11 18 3 4 10 16 7 8 9 14 1 8 14 q BOLT HEAD 1U IDENTIFICATION 20 25 25 30 40...

Page 92: ...t Inspect engine front and rear mountings as part of regular engine maintenance program Be sure to keep bolts and nuts tightened to torque values specified on chart CHEVROLET SERIES 70 90 HEAVY DUTY T...

Page 93: ...est of pressure cap and cooling system 1 Testing Radiator Cap CAUTION The radiator cap should not be removed while the engine is at normal operating temperature If it is necessary to remove the cap wh...

Page 94: ...ended due to plugging problems throughout various areas of the cooling system NOTE Refer to Standard Cooling System Capacities Chart at the end of this section for system capacities COOLING SYSTEM COR...

Page 95: ...stallation of 12V 71 D iesel engine on the left side of the engine There are four thermostats two in each side Pages 6K 9 and 6K 10 in Service Manual ST135 70 describes operation and checks When repla...

Page 96: ...or new fan drive belt is 255 to 265 pounds as indicated on gauge dial NOTE Tension for used fan drive belt after 1 hour or 50 m iles of running is 235 to 245 pounds 4 When belt has been adjusted to co...

Page 97: ...moved take out the retaining ring 5 Support the hub front face up on wooden blocks high enough to allow the bracket to be re moved Tap the fan shaft with a plastic hammer to free the fan shaft and bra...

Page 98: ...haft using a deep socket wrench remove nut 2 which attaches fan blade hub 1 to shaft assem bly 6 Using puller tool force hub from shaft Remove drive key 3 NOTE Retainer ring 4 need not be removed in o...

Page 99: ...IN G SYSTEM Manual ST135 70 page 6K 17 through 6K 20 ex cept that it is important when removing the im peller to protect the ceram ic insert from damage at all tim es during pump overhaul ALWAYS lay t...

Page 100: ...90 74 61 MC90 65 54 DP90 NOTE Optional Engines or Cooling System May Increase System Capacities 99 82 ENGINE THERMOSTATS ENGINE NUMBER USED MEAN TEMP F STARTS TO OPEN F FULL OPEN F V6 Gasoline Except...

Page 101: ...ir cleaner also acts as a flame arrester in the event the engine backfires Because backfiring may cause fire in the engine compartment the air cleaner should be installed at all times unless temporary...

Page 102: ...nts or attempt to clean by beating or rapping the element Dry element thoroughly Mechanical dryers can be used but heated air must be circulated and must be less than 180 After cleaning and drying and...

Page 103: ...of rod end assem bly A into relay lever NOTE If additional adjustment is required adjust position of rod end assem bly B on cable assem bly accordingly Minimum allowable thread engagement at either r...

Page 104: ...Is most important to use equal pressure on both screwdrivers when prying off the plastic caps to pre vent the idle mixture screw s from being bent If Idle mixture screw is bent during removal of plast...

Page 105: ...k out screw s until engine runs smoothly with highest vacuum gauge reading NOTE If vacuum gauge is not available adjust idle mixture screw s to give highest idle speed Turning idle mixture screw s in...

Page 106: ...b Adjust the plunger with a 3 8 inch open wrench until the face of the plunger hex contacting FLOAT LEVEL ADJUSTMENT 1 Remove air cleaner and disconnect choke and accelerator linkage and fuel line fr...

Page 107: ...9 TM WM80 401M or 478M 690120 RM80 401M or 478M 687116 381314 23 250 HM80 478SN 674795 381299 23 243 with Allison MT40 Transmission BENDIX STROMBERG CARBURETOR SPECIFICATIONS GM PART NO 685993 687115...

Page 108: ...GINE GOVERNED SPEED FULL LOAD Location At Engine Oil Pump 401M Engine 3400 RPM Type Centrifugal Pre set 478M Engine 3200 RPM SLAVE UNIT 478SN Engine 637 Engine 3200 RPM 2800 RPM Location Carburetor Th...

Page 109: ...ities Fuel filter elem ents on these engines should be replaced at regular intervals established by the operator Servicing of V12 71 fuel filters is same as described in Service Manual ST135 70 page F...

Page 110: ...e end freely enters at A Tighten lock nut then install pull back spring E ALUMINUM TILT CAB MODELS Refer to Figure 5 The cab mounted components of the acceler ator control mechanism are identical with...

Page 111: ...to 5 to 8 foot pounds 2 Rotate lever assem bly B to full throttle position and adjust stop D to contact accelerator Tighten stop bolts E V12 71 EMERGENCY STOP LINKAGE ADJUSTMENT FIG 6 NOTE Emergency s...

Page 112: ...r ties in the selection of D iesel fuels for optimum combustion and minimum engine wear Engine speed load and atmospheric tem per ature influence the selection of the fuel with re spect to distillatio...

Page 113: ...de overtravel and tighten lock nut D Replace spring E MB MODELS Refer to Figure 2 1 Adjust accelerator pedal stop G to 1 50 dimension from floor to head of bolt as shown Remove spring F 2 Loosen lock...

Page 114: ...SEL ENGINE 3 Loosen lock nut G Remove nut and re ator pedal is against pedal stop A by pushing move rod E at lever D Make sure acceler accelerator rod F rearward Adjust slip joint CHEVROLET SERIES 70...

Page 115: ...ual however the engine mounted compon ents differ according to engine type To adjust the linkage on all vehicles refer to figure 4 and the following instructions NOTE Hand throttle must be in OFF p os...

Page 116: ...nd storage facilities 3 Make necessary adjustments or repairs to accelerator linkage 4 Before stopping engine allow engine to idle three to five minutes 5 Turbo charged engine when started should be r...

Page 117: ...MENT Drive belt must be kept at proper tension A loose or broken belt w ill affect operation of the com pressor A drive belt that is too tight will place excessive strain on bearings All belt driven c...

Page 118: ...3 W M R 12 Water Belt None 90 SERIES N 6000 H M R 12 Air Belt None HE JE or 281415 B W 12 Air Belt Paper HH JH MH 282928 B W 12 Water Gear None HI Jl 282626 B W 12 Water Gear None TE N 6000 K M R 12 A...

Page 119: ...n Chart 149 Generating System Specifications 150 NOTE Refer to applicable wiring diagrams in Section 12 of ST135 70 for electrical circuits and connections for standard and optional equipment used on...

Page 120: ...tach one end of one jumper cable to the positive terminal of the booster battery identified by a red color or P on the battery case post or clamp and the other end of sam e cable to positive terminal...

Page 121: ...Sec 6Y 115 BATTERY BATTERY TEST PROCEDURE NOTE Chart No 1 is in Specifications T 803i CHEVROLET SERIES 70 90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT...

Page 122: ...listed at given temperature when battery is subjected to proper load for 15 seconds and is 1 200 specific gravity at 80 F or more C H A R T N O 1 V O L T A G E A N D T E M P E R A T U R E C H A R T El...

Page 123: ...normally closed contact points within the starter control relay With windings energized switch contacts will close to complete circuit to starter solenoid When engine is started current from R termin...

Page 124: ...ground through volt age sensing relay operating coil causing normally Figure 5 Circuit For Checking Motor Free Speed closed contact points to open thus breaking the circuit between the battery and ma...

Page 125: ...7000 Pinion Clearance 0 010 0 140 0 010 0 140 23 64 1 32 0 010 0 140 23 64 1 32 23 64 1 32 Includes Solenoid STARTER SOLENOID Model 1114356 1114359 1119848 1115510 1119862 1119879 Rated Voltage 12 12...

Page 126: ...SYSTEM in ENGINE ELECTRICAL SEC 6Y in Service Manuals ST135 70 and ST332 71 except as follows On the V6 401M engine set timing to 7 u be fore upper dead center BUDC with engine running atQ 525 rpm On...

Page 127: ...is used on vehicles covered by this supplement Information applicable to the non integral type alternating current generating system remains the same as covered under ALTERNATING CURRENT GENERATING S...

Page 128: ...unction within the charging system is used on steel tilt cab models An ammeter or voltmeter type charge indicator is available on all vehicles covered by this supplement Figure 1 illustrates a schemat...

Page 129: ...atic diagram of the generating system used on Series RM80 equipped with the 1119507 regulator and the 1115827 separate field relay unit is shown in figure 6 NOTE Schematic diagrams of generating sy s...

Page 130: ...d Relay Field Relay F Terminal No 2 Terminal No 3 Terminal No 4 Terminal T 8157 Figure 7 Vibrating Point Type Regulator Typical erator frame or that form s the generator fram e The rotor revolves with...

Page 131: ...a tor fig 7 On 62 amp generating system s except PLUG REMOVE TO ADJUST VOLTAGE SETTING NEG Figure 9 Full Transistor Type Regulator Model 9000590 Typical with 1117756 or 1117781 generator voltage is co...

Page 132: ...l system com ponents disconnect negative lead from the battery to prevent accidental shorting at generator and regulator term inals where battery voltage is avail able NOTE Replace voltage regulator w...

Page 133: ...lt tension on vehicles equip ped with the 8V 71 D iesel engine and Poly V drive belt should be adjusted to 84 94 pounds on a new belt or 64 74 pounds on a used belt GENERATING SYSTEM TROUBLE SYMPTOMS...

Page 134: ...to ground 3 Operate engine at slightly above idle speed and observe voltmeter If reading is 5 volts or above and lamp fails to go out replace the generator tell tale relay 4 If voltmeter reading is b...

Page 135: ...ector No 4 terminal 2 Connect the other test prod to ground on regulator base then turn ignition or con trol switch on and observe the voltmeter If voltmeter registers less than 3 volts the resistor i...

Page 136: ...g at idle speed check for an open relay or an open regula tor field circuit as follows a Connect a jumper lead between regulator base and a good ground If ammeter shows a slight charge the regulator i...

Page 137: ...regulator Connect a jumper lead between F term inal and No 3 terminal as shown in figure 13 4 Connect negative battery cable to battery Figure 14 Testing Field Relay Two Unit Regulator IMPORTANT With...

Page 138: ...r from regulator No 4 term inal to ground Turn ignition switch to ACC posi tion If reading is zero resistor is open FIELD RELAY CHECK If indicator lamp fails to go out with the gen erator in operation...

Page 139: ...s on the regulator a Turn ignition or control switch on and re cord the voltage drop b Make connections as shown in View B Part 2 figure 15 and record the voltage drop NOTE Voltmeter positive lead is...

Page 140: ...RATOR FIELD CIRCUIT USING VOLTMETER W I R I N G H A R N E S S VIEW C CHECKING GENERATOR FIELD CIRCUIT USING OHMMETER VIEW D CHECKING FOR EXCESSIVE RESISTANCE T 1547 Figure 17 Using Adapter J 2 1600 to...

Page 141: ...nce in the field winding or in wiring between regulator FLD terminal and generator FI terminal d If ohmmeter reads low the winding is shorted or grounded NOTE Since the reading is taken through the ad...

Page 142: ...bient tem per ature which is the temperature of the air measured at a distance of inch from the regulator cover Check and adjust voltage setting as follows 1 Insert a test prod into wiring harness con...

Page 143: ...an improved battery condition after a service per iod of reasonable length If necessary repeat the above procedure for a higher or lower setting SERVICE OPERATIONS GENERATOR REPLACEMENT Due to variati...

Page 144: ...r 4 Remove brush holder brushes and brush Armature Stop Feeler Gauge 1 0 Figure 21 Adjusting Field Relay Contact Points ITwo Unit Type Regulator springs from generator end frame NOTE If brushes are 1...

Page 145: ...s and locked in position 4 Connect negative battery cable to battery REGULATOR REPAIR MODEL 1119507 OR 1119515 While most regulator adjustments are made on the vehicle as outlined under On Vehicle Mai...

Page 146: ...it board heat sink and terminal assem bly from the regulator base 4 Note the insulation between the output tran sistor and heat sink and the insulators separating the heat sink from the panel board fi...

Page 147: ...solder the specific connections at points shown in figure 27 FILTER CAPACITOR PART 8 Fig 27 If both ohmmeter readings are zero the cap acitor is defective Visually inspect for open sold ered connectio...

Page 148: ...ngs in Step 14 or 14B are infinite or if both readings are very high and identical the transistor is open and must be replaced OUTPUT TRANSISTOR PART 15 Figs 29 and 30 In figure 29 if both readings in...

Page 149: ...replacing the relay 2 To check closing voltage connect a battery 50 ohm variable resistor and voltmeter into circuit as shown in figure 31 Slowly decrease resistance and note voltage at which relay p...

Page 150: ...transistor attaching screw s and separate the transistors and heat sink from the panel board With the transistors separated from the as sembly an ohmmeter may be used to check the transistors and com...

Page 151: ...s infinite or nearly infinite or if both readings are infinite or nearly infinite the resistor is open Figure 37 Checking Regulator Circuits POTENTIOMETER PARTS D AND E Fig 37 If one reading is infini...

Page 152: ...2 14 28 2000 40 5000 42 Delco Remy 10DN 100 Clockwise 2 2 2 6 12 14 33 2000 58 5000 61 Delco Remy 20DN 150 Clockwise 4 1 4 6 12 14 20 1100 55 2500 62 Delco Remy 20DN 250 Clockwise 4 1 4 6 12 14 20 110...

Page 153: ...No 2 a Allowable Range at O Position of Adjusting Screw T E M P E R A T U R E V O L T A G E C H A R T N O 2 Regulator Ambient Temp Deg F 65 85 105 125 145 165 185 Voltage Setting 14 1 14 8 13 9 14 7...

Page 154: ...80 With 62 Amp Generator Model 1117781 Bolt 25 30 With 62 Amp Generator Model 1117787 Bolt 25 30 Generator to Mounting Bracket or Support Bracket Pivot Bolt With 42 Amp Generator Nut 25 30 With 61 Am...

Page 155: ...lid state regulator mounted inside the generator slip ring end frame All regulator components are enclosed in a solid mold This unit is attached to the slip ring end fram e The regulator voltage setti...

Page 156: ...r ating system troubleshooting procedures remains the sam e as covered under Troubleshooting Pro cedures on pages 6Y 51 through 6Y 54 in the 1970 Heavy Duty Truck Service Manual ST135 70 except as fol...

Page 157: ...moved or replaced 3 After transmission has been removed and reinstalled in vehicle 4 When the transm ission is not performing properly WARNING DO NOT START ENGINE WITH SHIFT LINKAGE DISCONNECTED AS SE...

Page 158: ...celerator rod assem bly P from cross shaft lever R c Depress accelerator pedal K to THRU DETENT detent button O com pressed Ample clearance must exist between the pedal and cab floor to assure complet...

Page 159: ...irectly 9 Move TV lever N full clockwise as shown in figure 4 TV lever should be aligned with THRU DETENT line This step is a check to be sure no internal condition exists in the transm ission that wo...

Page 160: ...DETENT Referring to figure 6 TV lever should be aligned with LONG STROKE line on gauge NOTE Any under or over travel in Step 15 indicates faulty or improper linkage components 16 Remove gauge from tra...

Page 161: ...and floor to assure complete movement of the TV linkage to the THRU DETENT position If necessary ad justment of the detent button E is accomplished by relocating the two jam nuts located on the deten...

Page 162: ...o check for full load upshift 5th to 6th Upshift should occur at ap proximately 50 rpm below the engine governed speed 3400 rpm with 401M engine If upshifts do not occur at specified rpm adjust as fol...

Page 163: ...ng a tachometer to accurately check engine rpm with selector lever in N neutral recheck engine idle speed 525 rpm Road test or dynamometer test vehicle to check for full load upshift 5th to 6th Upshif...

Page 164: ...n figure 5 10 With accelerator linkage at IDLE posi tion have assistant position slotted clevis K so upper portion of slot contacts clevis pin M Se cure clevis K to clevis pin M Tighten nut J against...

Page 165: ...ghten jam nut against clevis install clevis pin and secure with cotter pin 6 After completing all adjustments operate vehicle and check operation of the selector lever through all shift ranges Readjus...

Page 166: ...ct spacers approximately equal to this gap 50 60 FT LBS t 031 NOTE The maximum perm issible gap after spacer installation is 1 32 inch Spacers are avail able 1 32 and 1 16 inch thick There may be a di...

Page 167: ...s as shown in figure 2 Be sure all attach ing parts are properly torqued NOTE Shims are U shaped for ease in install ation and are available in three sizes 0 25 0 12 and 0 06 f Check the installed hei...

Page 168: ...ter at rear of the transm ission 8 Disconnect the propeller shaft from trans m ission as described in PROPELLER SHAFTS SEC 4D of the 1970 Heavy Duty Truck Service Manual ST135 70 9 Disconnect the mech...

Page 169: ...fuel tanks special equipment etc on som e vehicles to provide clear TRANSMISSION ON VEHICLE SERVICE ance before the transm ission is removed NOTE Troubleshooting maintenance and overhaul information...

Page 170: ...HILE IN A DRIVE RANGE BE SURE IGNITION SWITCH IS IN THE O FF POSITION B EFO R E PROCEEDING TO THE NEXT S TEP 12 Install spark plugs and connect battery ground strap previously disconnected for safety...

Page 171: ...FRAME t____ CROSS BEAM 90 110 FT LBS 190 210 FT LBS ____ Jfc td__________ r i r i i i i i 4 I u 3 J CUSHION ASSEMBLY 70 80 FT LBS VIEW D REAR MOUNT SPICER 8341 SPACER AUXILIARY TRANSMISSION VIEW E FRO...

Page 172: ...does not have the tapered surface Shown in View F figure 1 2 With transm ission mounted on a suitable dolly or jack move into position under the vehicle Adjust frbnt and rear height as listed in Auxi...

Page 173: ...iodic intervals to per mit full engagement of the clutch Adjustment is necessary when pedal free travel is reduced to le ss than inch Adjust linkage as follows MODELS HV JV70 AND HM JM80 WITH 478M ENG...

Page 174: ...nd 11 2 Lengthen clutch rod by two turns rotate upper adjusting nut until it contacts clutch rod Tighten upper lock nut against upper adjusting nut 3 Disconnect clutch lever return spring from release...

Page 175: ...icer clutches Be sure to first adjust the clutch internally as described in Internal Clutch Adjustment in the 1970 Heavy Duty Truck Service Manual ST135 70 pages 7 4 3 7 4 5 After the internal clutch...

Page 176: ...ng steps the rear idler lever must be held against STOP as shown and the clutch lever return spring discon nected as shown 3 Loosen upper adapter adjusting nut left hand threads and the lower adapter...

Page 177: ...LUTCH LINKAGE ADJUSTMENT Linkage adjustment procedures for the DB FB90 are the same as described in the 1970 Heavy Duty Truck Service Manual ST135 70 pages 7 42 7 45 CLUTCH IDLER LEVER REPLACEMENT SER...

Page 178: ...e as described for Spicer Clutches in the 1970 Heavy Duty Truck Service Manual ST135 70 SETSCREWS DRIVE PIN FLYWHEEL HOUSING PILOT BEARING CLUTCH HOUSING ADJUSTING RING LOCK LEVER RELEASE SLEEVE RETAI...

Page 179: ...nks Empty the tank and make necessary repairs Reinstall gauge unit and install tank to vehicle Connect lines and wire and when repair area is cool refill tank with fuel to prevent rust formation If ta...

Page 180: ...uge according to position of the float The tank unit rheostat may be checked for accur acy with an ohmmeter With float in EMPTY po sition an ohmmeter connected across the rheostat should indicate 0 to...

Page 181: ...ose temporarily until the entire system has been inspected to determine if there is adequate clear ance between exhaust components and frame mem bers The weight of the exhaust system should be properl...

Page 182: ...STED TRAFFIC TO PREVENT DEADLY EXHAUST GASES FROM EN TERING CAB IMPORTANT Some areas of the country require that an operating vehicle m eets a noise m eter test For assurance of minimum exhaust system...

Page 183: ...following IMPORTANT When installing steering wheel be sure to place special hardened flat washer under the attaching nut STEERING IDLER LEVER BUSHING REPLACEMENT MODEL RM80 All information in the 1971...

Page 184: ...overed in this supple ment will have the side cover attached to the main housing with flange type cap screw s On steering gears 553DV and 555DV the stub end of the steering gear worm shaft fig 4 will...

Page 185: ...sible that the mast jacket clamps and lower steering shaft clamp need adjusting The clunking is caused by up and down movement of upper and lower shaft joints and can be eliminated as follows This dim...

Page 186: ...n Arm Stud Idler Lever Pivot B o lt Idler Link to Idler Lever Stud Idler Lever t Frame Stud Nut 45 50 Bolt 8 10 Nut 8 10 Bolt 20 25 Bolt 20 25 Bolt 8 12 Nut 8 12 Bolt 35 40 Nut 40 50 Nut 35 45 Nut 35...

Page 187: ...cement the entire steering system should be cleaned and flushed out Due to scoring of the pump at tim e of failure the control valve and cylinder should be disas sembled and any particles of metal wip...

Page 188: ...5 70 on page 9 29 is appli cable to models covered by this supplement The following information also applies The 553 DV 554 DV and 568 DV type power steering gear assem blies are basically the same ex...

Page 189: ...Bolt 18 Valve Lower O ring Seal 19 Hydraulic Valve Assembly 20 Valve Upper O ring Seal 21 Worm Upper Thrust Bearing 22 Adapter O ring Seal 23 Valve to Housing Adapter 24 Drain Plug 25 Pitman Shaft Sec...

Page 190: ...235 P 141 Capacity Per Minute Maximum 4 25 gpm of Power Steering fluid at 170 F temperature when operating pump against 50 psi pressure at 1500 R P M Minimum 2 35 gpm of Power Steering fluid at 170 F...

Page 191: ...T 70 80 With F 070 Front Axle F 090 F 120 Front Axle Series T W 70 80 90 D F90 With F 090 Front Axle F 120 F 160 Front Axle Side Axle Axle Axle Axle Axle 16 680 17 936 16 680 19 806 17 936 19 806 25...

Page 192: ...Idler Shaft Clamp Bolt Drag Link to Pitman Arm Stud Conventional Cab Models Drag Link to Idler Lever Stud Series RM 80 Tilt Cab Models Drag Link to Steering Arm Stud R H Drag Link to Idler Arm Stud W...

Page 193: ...hubs by bolts and ball seat type nuts Unique in the dual rear attachment is the inner and outer threaded nut arrangement permitting removal of outside wheel without inter fering with inner wheel WHEE...

Page 194: ...rts wheel shimmy and extreme tread wear Excessive mounting torque can cause damage by stripping studs collapsing spacer bands out of round rim condition or broken studs or cracks in the stud hole area...

Page 195: ...arefully because damage to hub studs or wheel may have been caused by running in this condition Damaged or Sprung Rings Broken or cracked rings as shown in figure 7 are generally caused by rough use o...

Page 196: ...imum load adjust air pressure downward to correspond to the actual load carried Never bleed tires to relieve build up of pressure Tire temperature will increase when the tire is in service and allows...

Page 197: ...rnering Wear When a truck makes an WHEELS AND TIRES extrem ely fast turn the weight is shifted from an even loading on all wheels to an abnormal load on the tires on the outside of the curve and very...

Page 198: ...the tires are not moving in a straight path The sam e thing happens when spread axle tires are dragged or pushed sideways for example while spread axle trailers are being spotted at or pulled away fro...

Page 199: ...the two largest tires on one side of one axle and mount the two sm allest on the opposite side of the sam e axle 5 Mount the four other tires on the other axle in the sam e manner 6 Test run the vehi...

Page 200: ...ar when 1 5 of the tread design is worn off Then match tires on each wheel as already described but with an additionalprecaution the sum of the circum ferences of the four tires for the front of the t...

Page 201: ...ed or folded over at edges should not be used again TUBES AND CASINGS DAMAGED BY FOREIGN MATERIALS IN CASINGS Any foreign m aterial between the casing and tube w ill cause a chafing action In tim e on...

Page 202: ...ap of adequate width to prevent tube pinching As a precaution against flap failure mark the tire and rim size on the flap at the tim e of removal if inspection shows that it is not damaged and can be...

Page 203: ...hammer end of ring into place with rim mallet To disengage lock ring from the gutter insert rim tool in removing notch near split in the ring and push downward If desired a second similar tool may be...

Page 204: ...ing from the gutter insert one rim tool in tool slot of side ring and pry ring upward and outward This operation can be assisted as shown by inserting hooked end tool between the tire and ring prying...

Page 205: ...ull one tool toward center of rim Hold tool in position with one foot and pull second tool toward center of rim Progressively work bead off rim tak ing additional bites if necessary Hold second bead i...

Page 206: ...l free Insert straight end of rim tool in operating notch point B then pull in direction indicated by arrow R e tain pressure with tool and strike ring downward with mallet at point be tween tool slot...

Page 207: ...protective measure is of particular importance with drop center tubeless rim s as the air in the tire is contained by the tire sid e rim surface Remove Rust and Other Foreign Matter Accumulation of su...

Page 208: ...Sec 10 p02 WHEEL AND TIRES Figure 20 Rim and Wheel Safety Precautions CHEVROLET SERIES 70 90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT...

Page 209: ...ng Equipment Fig 20 View H TIRE SPREADER ARMS CAN BE DANGEROUS Keep them closed when the machine is idle and use care in all respects while operating the spreader Face and Eye Protection ALWAYS WEAR G...

Page 210: ...fire are useful in preventing the fire from spreading to vehicle and cargo If possible a steady stjream of water should be placed on the tire until it is cool enough for removal The best protection a...

Page 211: ...3890 4050 4210 4350 4500 9 00 15 F 2950 3150 3330 3500 3660 3830 3980 4140 4290 9 00 18 E 3320 3530 3730 3920 4120 4300 9 00 20 E 3560 3770 4000 4210 4410 4610 9 00 20 F 3560 3770 4000 4210 4410 4610...

Page 212: ...0 4780 4990 5190 11 00 20 G 4100 4330 4560 4780 4990 5190 5390 5590 5780 11 00 22 F 4350 4600 4840 5080 5300 5520 11 00 22 G 4350 4600 4840 5080 5300 5520 5730 5940 6140 11 00 24 F 4620 4890 5140 5390...

Page 213: ...acket Remove the extension assem bly 3 Separate the metal brace rods from exten sion Note the number of shim washers at lower end of brace rod INSTALLATION A ssem ble and install extension assem bly i...

Page 214: ...ly repaired after sanding down then using plastic filler FIBERGLASS HOOD ALIGNMENT On Models HH JH HC and JC the hood as sembly is adjustable fore and aft right and left after loosening the hood hinge...

Page 215: ...NOT use regular copper wire in place of this resistance wire On vehicles equipped with the V8 637 gasoline engine a 1 35 ohm resistance wire is used in the engine wiring harness to connect the IGN te...

Page 216: ...ar connectors in the wiring harness be cleaned and lubricated with a multi purpose grease whenever the connector is separated or whenever difficulty caused by corrosion has been encountered The lubric...

Page 217: ...onnector to R H Front D irectional Lamp 16 Blk BZ L H DIRECTIONAL LAMP From Spliced Connection From Instrum ent Panel H arness 8 Way C o n n e c to r 18 Blue W ht Cr Tr To 2 W ay Connector To L H Fron...

Page 218: ...side pinel between the door pillar and back of cab The junction block cover must be removed for access to junction term inals NOTE On some models the wiring connec tions are made by use of mating con...

Page 219: ...hassis junction block fig 3 is located under completed through a 6 term inal junction block left hand step riser panel and is accessible when The tabulation which follows lists each term left door is...

Page 220: ...EMPERATURE GAUGE From Water Tem perature Gauge 18 Dk Grn To Water Tem perature Sender 16 Blk AMMETER From A m m e t e r 18 B lk W ht S tr To 4 Am p Fuse in Fuse H o ld e r 14 Blk R H CHASSIS JUNCTION...

Page 221: ...r Code 1 TAIL LAMPS TRAILER From L H Junction Block 1 J u n c t io n 12 Brn To 6 W ire S em i T railer Plug 14 Brn To 7 W ire S em i T railer P l u g 12 Brn 2 L H DIRECTIONAL LAMP TRAILER From R H Jun...

Page 222: ...E GAUGE From Multiple Connector From Tem perature Gauge 16 To Rear E lectrical Equipment Panel Junction Block 4 Junction 16 6 jOIL GAUGE From Multiple Connector From Oil Gauge 16 To 5 Junction on Rear...

Page 223: ...top Lamp Switch TRL 16 Red To 6 W ire S em i T railer P l u g 14 Red To 7 W ire S em i T railer P l u g 12 Red 5 TRAILER I C C MARKER LAMPS From Marker Lamp Switch O N 16 Blk To I C C M arker L a m p...

Page 224: ...sticks closed the defective circuit breaker must be replaced Circuit breakers must be installed so the feed or battery w ire is connec ted to the Battery or short terminal and the wire or wires carry...

Page 225: ...ts to each term inal C ircuit Breaker No Am ps 1 10 15 15 15 15 Wire C ircuit Size LIGHT SWITCH From Battery Junction B l o c k 12 To Multiple Connector to Light S w i t c h 14 STOP LIGHTS From Igniti...

Page 226: ...h 12 20 DIRECTIONAL AND HAZARD WARNING AND CIGAR LIGHTER From Battery Bus Bar To Flasher Term inal X 12 To Cigar L ig h t e r 12 5 GAUGE AND INSTRUMENT LAMPS From Light Switch No 2 T e r m in a l 16 T...

Page 227: ...e Manual ST135 70 except a schem atic diagram of the horn control circuit fig 8 has been added to clarify procedures used in checking the horn circuit If the horn fails to operate use a jumper lead to...

Page 228: ...as covered under Instruments and Gauges in CHASSIS ELECTRICAL AND IN STRUMENTS SEC 12 pages 12 117 through 12 23 in Service Manual ST135 70 except as follows HI BEAM TELl TAlE GRN WHT CR 1K J FOUR UNI...

Page 229: ...12 13 14 15 16 1 Temperature Gauge 2 Differential Lock T ell tale 3 Speedometer 4 Fuel Gauge 5 Hi Beam T ell tale 6 Air P ressure Gauge Vacuum Gauge Voltmeter or Ammeter 11 12 13 14 7 Tachometer 8 Eng...

Page 230: ...into back of cluster Series 7 0 t h r o u g h 9 0 TILT CAB MODELS Information applicable to the instruments and gauges used on steel tilt cab models remains the same as covered under Instruments and...

Page 231: ...ASSIS ELECTRICAL AND INSTRUMENTS DIRECTIONAL AND HAZARD WARNING LIGHTS Information applicable to Directional Signal Lights and the Hazard Warning System remains the sam e as covered under Lighting Sys...

Page 232: ...d Front Directional and Side Marker Light 1156 32 Side Marker Light 1895 2 Front Marker Lights 1155 1641 4 STOP TAIL AND DIRECTIONAL LIGHT 115 32 BACK UP LIGHT 1156 32 LICENSE LIGHT 67 4 INSTRUMENT AN...

Page 233: ...r Electrical Equipment Panel Chock and Starter Relay Switch 30 Amp On Rear Electrical Equipment Panel Stop and Tail Lamp 15 Amp On Front Electrical Equipment Panel Ignition 15 Amp On Front Electrical...

Page 234: ...Engine Harness at Fire Wall SERIES 70 90 TILT CAB MODELS Heater 15 3AG or AGC In Fuse Block Inside Cab Directional and Hazard Warning 20 SAE In Fuse Block Inside Cab Stop Back up Lamps 20 SAE or AGC I...

Page 235: ...engthened or shortened by moving ad justing nuts up or down and then torque nuts to 15 to 20 foot pounds Figure 1 Stabilizer Rod IM odels HC JC HH and JH 90 DC FC90 with NTC 335 Engine When properly a...

Page 236: ...lift radiator assem bly into position in vehicle NOTE Be sure to install upper cushion on radiator support fig 3 2 Install washers and cushions on two bolts fig 3 Install bolts through radiator suppor...

Page 237: ...radiator support 8 Attach a lifting sling or chain to each rad iator upper mounting bracket 9 Remove any other tubes brackets or lines that would interfere with vertical removal of radiator 10 With a...

Page 238: ...cock in supply line at air tank 6 Carefully install air conditioning andpower steering cooling coils power steering reservoir and receiver dehydrator if removed 7 Connect or install all other item s t...

Page 239: ...a defective cooling system incorrect ignition timing dragging brakes under inflated tires and improper use of trans m ission gears can cause overheating 2 Keep water pump and fan drive belts at proper...

Page 240: ...TION 4B REAR SUSPENSION Tool No Tool Name J 2619 Slide Hammer Adapter SECTION 5B AIR BRAKES N A Nylon Tubing Fitting Installer Kit Includes various size mandrels SECTION 6A GASOLINE ENGINES A C Type C...

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Chevrolet DB90 Series, Service Manual

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