Komatsu Service Manual D20A, P, S, Q-6, D21A, P, S & Q-6 Volume 1 of 2 Service Manual THIS IS A MANUAL PRODUCED BY JENSALES INC. WITHOUT THE AUTHORIZATION OF KOMATSU OR IT S SUCCESSORS. KOMATSU AND IT S SUCCESSORS ARE NOT RESPONSIBLE FOR THE QUALITY OR ACCURACY OF THIS MANUAL. TRADE MARKS AND TRADE NAMES CONTAINED AND USED HEREIN ARE THOSE OF OTHERS, AND ARE USED HERE IN A DESCRIPTIVE SENSE TO REFER TO THE PRODUCTS OF OTHERS. KOM-S-D20AP+
CONTENTS 10 ENGINE 12 TESTING AND ADJUSTING.... 13 DISASSEMBLY AND ASSEMBLY.... No. of page 12-1 13-1 20 POWER TRAIN 21 STRUCTURE AND FUNCTION............................................... 21-1 22 TESTING AND ADJUSTING... 22-1 23 DISASSEMBLY AND ASSEMBLY... 23-1 24 MAINTENANCE STANDARD.... 24-1 30 UNDERCARRIAGE 31 STRUCTURE AND FUNCTION.... 31-1 33 DISASSEMBLY AND ASSEMBLY... 33-1 34 MAINTENANCE STANDARD.... 34-1 60 HYDRAULIC SYSTEM 61 STRUCTURE AND FUNCTION............................................... 61-1. 62 TESTING AND ADJUSTING........................... 62-1 63 DISASSEMBLY AND ASSEMBLY... 63-1 64 MAINTENANCE STANDARD.... 64-1 70 WORK EQUIPMENT 71 STRUCTURE AND FUNCTION :.............................................. 71-1 73 DISASSEMBLY AND ASSEMBLY... 73-1 74 MAINTENANCE STANDARD... 74-1 80 ELECTRICAL SYSTEM 81 STRUCTURE AND FUNCTION.......................... 81-1 00-2 020,21-6
ENGINE.2 TESTING AND AD~USTING Testing and adjusting data................. 12-2 Tool list for testing and adjusting........... 12-3 Adjusting valve clearance... 12-4 Measuring exhaust gas color............... 12-5 Measuring compression pressure........... 12-6 Measuring blow-by pressure............... 12-7 Adjusting fuel injection timing.............. 12-8 Testing and adjusting fan belt tension....... 12-9 A A A A When carrying out testing, adjusting or troubleshooting, stop the machine on level ground, apply the lock levers and block the tracks. When working in groups, use agreed signals and do not allow unauthorized persons near the machine. When checking the water level in the radiator, wait for the water to cool. Do not remove the radiator cap while the water is hot. Boiling water may spurt out. Be careful not to get caught in rotating parts. 020,21-6 12-1 CD
ENGINE 13 DISASSEMBLY AND ASSEMBLY 8T ARTING MOTOR Removal and Installation............... 13-2 ALTERNATOR Removal and Installation... " 13-2 WATER PUMP Removal and Installation............... 13-2 FUEL INJECTION PUMP Removal and Installation............... 13-4 NOZZLE HOLDER Removal and Installation............... 13-4 CYLINDER HEAD Removal and Installation............... 13-6 RADIATOR GUARD Removal and Installation............... 13-8 RADIATOR Removal and Installation............... 13-10 THERMOSTAT Removal and Installation............... 13-10 ENGINE Removal............................. 13-12 Installation... 13-14 020.21-6 13-1 ;2
POWER TRAIN %1 STRUCTURE AND FUNCTION General (020-6).................. 21-2 General(021A,P,S,Q-6,021P-6A)... 21-4 General (021 E-6, 021 P-6B, 021 S-6A)... 21-6 Power train hydraulic system (021A,P,S,Q-6,021P-6A)... 21-8 Power train hydraulic circuit diagram (021 A, P, S, Q-6, 021 P-6A)... 21-9 Power train hydraulic system (021E-6,021P-6B,021S-6A)... 21-10 Power train hydraulic circuit diagram (021 E-6, 021 P-6B, 021 S-6A)......... 21-11 Main clutch (020-6)... 21-12 Main clutch control (020-6)... 21-17 Tramsmission (020-6)... 21-18 Oamper and universal joint (021A,P,S,Q-6,021P-6A)... 21-22 Oamper and universal joint (021 E-6, 021 P-6B, 021 P-6A)......... 21-23 HYOOROSHTFT transmission (021A, P, S, Q-6, 021 P-6A)... 21-24 HYOOROSHIFT transmission (021 E-6, 021 P-6B, 021 S-6A)......... 21-30 Transmissoion control (021 A, P, S, Q-6, 021 P-6A)... 21-36 Transmissoion control (021 E-6, 021 P-6B, 021 S-6A)... 21-37 HYOOROSHIFT transmission hydraulic system (021A,P,S,Q-6,021A-6A)... 21-38 HYOOROSHIFT transmissoin hydraulic circuit diagram (021 A, P, S, Q-6, 021 P-6A)... 21-39 HYOOROSHIFT transmission hydraulic system (021 E-6, 021 P-6B, 021 S-6A)......... 21-40 HYOOROSHIFT transmission hydraulic ciucuit diagram (021 E-6, 021 P-6B, 021 S-6A). 21-41 Transmission control valve (021A,P,S,Q-6,021P-6A)... 21-42 Transmission control valve (021 E-6, 021 P-6B, 021 S-6A)......... 21-44 Transmission pump (021-6)... 21-51 Bevel gear shaft and steering clutch... 21-52 Steering control... 21-55 Steering hydraulic piping (020-6)... 21-56 Steering hydraulic piping (021-6)... 21-57 Steering hydraulic system (020-6)... 21-58 Steering hydraulic circuit diagram (020-6).. 21-58 Steering hydraulic system (021-6)... 21-59 Steering hydraulic circuit diagram (021-6).. 21-59 Main clutch and steering pump (020-6)... 21-60 Steering main relief valve (020-6)... 21-61 Steering control valve................. 21-62 Steering booster cylinder... 21-65 Steering brake...,..., 21-66 Final drive................................ 21-68 020,21-6 21-1 J:!
POWER TRAIN Z2 TESTING AND AD~USTING Standard for testing and adjusting.......... 22-2 Testing and adjusting tool list ~...,... 22-4 Measurng oil pressure..................... 22-5 Measuring oil temperature... 22-7 Testing travel... 22-8 Measuring operating force... " 22-10 Adjusting fuel control lever... 22-12 Adjusting main clutch control linkage... 22-13 Adjusting inching control linkage... 22-14 Adjusting gear shift lever control linkage... 22-16 Adjusting steering control linkage... 22-17 Adjusting brake control linkage............. 22-18 Troubleshooting.......................... 22-19 A When carrying out testing, adjusting or troubleshooting, stop the machine on level ground, install the safety pins and block the tracks. A When working in groups, use agreed signals and do not allow unauthorized persons near the machine. A When checking the water level in the radiator, wait for the water to cool. Do not remove the radiator cap while the water is hot. Boiling water may spurt out. A Be careful not to get caught in rotating parts. 020,21-6 22-1 CD
POWER TRAIN 23 DISASSEMBLY AND ASSEMBLY MAIN CLUTCH (D20-6) Removal and Installation............... 23-2 Disassembly.......................... 23-4 Assembly... ~. 23-10 TRANSMISSION (D20-6) Removal and Installation............... 23-16 Disassembly.......................... 23-18 Assembly......... 23-24 DAMPER (D21-6) Removal and Installation............... 23-32 HYDROSHIFT TRANSMISSION (D21-6) Removal... 23-34 Installation... 23-38 Disassembly (D21 A,P,S,Q-6, D21 P-6A)... 23-42 Assembly (D21 A,P,S,Q-6, D21 P-6A) 23-58 Disassembly (021 E-6, D21 P"-6B, D21 S-6A)..... 23-76 Assembly (D21 E-6, D21 P-6B, D21 S-6A)..... 23-90 TRANSMISSION PUMP (D21-6) Removal... 23-106 Installation... 23-110 MODULATING VALVE (D21-6) Removal and Installation.............. 23-114 Disassembly and Assembly... 23-116 STEERING PUMP (D20-6) Removal and Installation.............. 23-120 STEERING MAIN RELIEF VALVE (D20-6) Removal and Installation.............. 23-1 20 STEERING VALVE Removal and Installation... 23-122 Disassembly and Assembly... 23-122 STEERIGN CLUTCH Removal... 23-1 24 Installation... 23-128 Disassembly... 23-132 Assembly... 23-134 BEVEL GEAR SHAFT AND BEVEL GEAR Removal... 23-138 Installation... 23-142 FINAL DRIVE Removal and Installation... 23-150 FINAL DRIVE FIRST PINION Removal and Installation:... 23-152 FINAL DRIVE Disassembly......................... 23-154 Assembly... 23-158 SELECTOR AND INCHING VALVE (D21-6) Removal and Installation........ 23-114 Disassembly and Assembly... 23-118 D20,21-6 23-1 ~
POWER TRAIN 24 MAINTENANCE STANDARD Main clutch (020-6)... 24-2 Main clutch and steering pump (020-6)... 24-5 Transmisson (020-6)... " 24-6 Oamper and universal joint (021-6)......... 24-9 HYOOROSHIFT transmission (021A, P, S, 0-6, 021 P-6A)... 24-10 HYOOROSHIFT transmission. (021 E-6, 021 P-6B, 021 S-6A)......... 24-12 Transmission control valve (021A,P,S,O-6,021P-6A)... 24-14 Transmission control valve (021 E-6, 021 P-6B, 021 S-6A)......... 24-16 Transmission and steering pump (021-6).,. 24-18 Bevel gear shaft... 24-1 9 Steering clutch... 24-20 Steering main relief valve (020-6)... 24-22 Steering control valve... 24-23 Steering booster cylinder............... 24-24 Steering brake............................ 24-25 Final drive................................ 24-26 020,21-6 24-1
UNDERCARRIAGE 3I STRUCTURE AND FUNCTION Track (dry type track link) (020,21 A, E, P-6)... 31-2 Track (lubricated track link) (021, 21A, E, P-6)... 31-3 Track (dry type track link) (020,215,0-6)... 31-4 Track (lubricated track link) (020,215,0-6)... 31-5 Track group (020, 21A, P, 5, Q-6, 020, 21 P-6A}... 31-6 Track group (021 E-6, 021 P-6B, 021 5-6A, 020,21 Pl-6, 021 PLl-6).............. 31-7 Idler.... Idler cushion.... Track roller.... Carrier roller.... Main frame and suspension.... 31-8 31-9 31-10 31-10 31-11 D20.21-6 31-1
UNDERCARRIAGE 33 DISASSEMBLY AND ASSEMBLY TRACK FRAME Removal and Installation............... 33-2 RECOIL SPRING Removal and Installation............... 33-4 Disassembly and Assembly... 33-6 IDLER Removal and Installation............... 33-6 CARRIER ROLLER Removal and Installation............... 33-8 TRACK SHOE (020,21,A,E,S,Q-6, 020,21 P-6A,B) Removal and Installation............... 33-1 (020,21 P,PL-6) Removal and Installation................ 33-12 020,21-6 33-1
UNDERCARRIAGE 34 MAINTENANCE STANDARD Track (dry type track link) (020. 021 A. E. P-6)...,.... 34-2 Track (lubricated track link) (020. 21 A. E. P-6).......... 34-4 Track (dry type track link) (020. 21 S. Q-6)... 34-6 Track Uubricated track link) (020. 21 S. Q-6)... 34-8 Track frame... 34-10 Idler cushion... 34-11 Idler.................................... 34-1 2 Track roller... 34-14 Carrier roller...,...,............... 34-1 5 D20,21-6 34-1
HYDRAULIC SYSTEM 61: STRUCTURE AND FUNCTION Hydraulic piping (020,21 A, E-6, 020, 21 P-6A, Bl Hydraulic control (020,21 A, E-6, 020, 21 P-6A, Bl Hydraulic circuit system (020,21 A, E-6, 020, 21 P-6A, Bl Hydraulic circuit diagram (020,21 A, E-6, 020, 21 P-6A, Bl Hydraulic piping (020,21 P, PL, PLL-6l.... Hydraulic control (020, 21 P, PL, PLL-6l.... Hydraulic circuit system (020,21 p, PL, PLL-6l.... Hydraulic circuit diagram (020,21 P, PL, PLL-6l.... Hydraulic piping (020,21 S, 0-6, 021 S-6Al.... Hydraulic control (020,21 S, 0-6, 021 S-6Al.... Hydraulic circuit system (020, 21S, 0-6, 021A-6Al.... Hydraulic circuit diagram (020,21 S, 0-6, 021 S-6Al.... Hydraulic tank and filter.... Hydraulic pump.... Hydraulic control valve 61-2 61-3 61-4 61-5 61-6 61-7 61-8 61-9 61-10 61-11 61-12 61-13 61-14 61-15 (020, 21A, E-6, 020, 21 P-6A, B)... 61-16 Hydraulic control valve (020, 21P,PL,PLL-6}... 61-18 Hydraulic control valve (020, 21S, 0-6, 021S-6A}... 61-20 Hydraulic lever operation (020, 21A, E, P-6). 61-26 Hydraulic lever operation (020,21 S, 0-6).., 61-32 Hydraulic cylinder (020,21 A, E-6, 020,21 P-6A, B)... 61-36 Hydraulic cylinder (020, 21 P, PL, PLL-6)... 61-38 Hydraulic cylinder (020,21 S, 0-6, 021 S-6Al... 61-40 020,21-6 6 1-1
HYDRAULIC PIPING 020, 21 A-6, 021 E-6, 020, 21P-6A, 021P-68 5 I03F06041 1. Hydraulic tank 2. Hydraulic pump 3. Hydraulic control valve 4. Blade lift cylinder 5. Blade angle cylinder 6. Blade tilt cylinder 7. Hydraulic filter OUTLINE The oil in hydraulic tank (1) is sucked up by hydraulic pump (2) installed to the engine, and is sent to hydraulic control valve (3). The hydraulic control valve sets the pressure in the circuit to 155 kg/cm2.lt switches the flow of oil to lift cylinder (4), angle cylinder (5), or tilt cylinder (6) to operate the blade according to the movement of the work equipment control lever. If the hydraulic control valve is at the "HOLD" position, the oil enters hydraulic filter (7) installed to the hydraulic tank and returns to the hydraulic tank. The hydraulic filter is a cartridge type with a filtering precision of 10 J.l, and a maximum filteririg rate of 1 OOX~/min, and the normal pressure is set to 1.5 kg/ cm2 The total capacity of the hydraulic tank is 33 liters, with the amount of oil inside the tank set to 20 litres. 61-2 020,21-6
HYDRAULIC SYSTEM 62- TESTING AND AD'--'USTING Standard for testing and adjusting.......... 62-2 Testing and adjusting tool list... 62-3 Measuring and adjusting oil pressure........ 62-4 Measuring oil temperature............... 62-5 Bleeding air from angle cylinder head circuit................... 62-5 Testing travel... 62-6 Measuring operating force... 62-6 Testing performance of work equipment... 62-7 Measuring hydraulic drift of work equipment... 62-9 Troubleshooting.......................... 62-11 A When carrying out testing, adjusting or troubleshooting, stop the machine on level ground, install the safety pins and block the tracks. A When working in groups, use agreed signals and do not allow unauthorized persons near the machil)e. A When checking the water level in the radiator, wait for the water to cool. Do not remove the radiator cap while the water is hot Boiling water may spurt out. A Be careful not to get caught in rotating parts. A Bleeding air from hydraulic cylinder. After replacing or installing hydraulic cylinders or hydraulic piping, bleed the air from the hydraulic cylinders as follows: 1. Start the engine and run at idling for about 5 minutes. 2. Run the engine at low idling, and raise and lower the work equipment 4-5 times. * Stop the piston rod about 100 mm from the end of the stroke. Never operate it to the relief position. 3. Run the engine at full throttle and repeat the above procedure. Then run the engine at low idling and operate the piston rod to the end of the stroke to relieve the circuit. 020,21-6 62-1,.
HYDRAULIC SYSTEM 63 OISASSEMBL Y AND ASSEMBLY HYDRAULIC PUMP Removal and Installation............... 63-2 HYDRAULIC CONTROL VALVE Removal and Installation............... 63-2 Disassembly (020,21 A,E-6, 020,21 P-6A,B) 63-4 Assembly (020,21 A,E-6, 020,21 P-6A,B) 63-6 Disassembly (020,21 P,PL-6) 63-8 Assembly (020,21 P,PL-6)... 63-1 Disassembly (020,21 S,0-6)........... 63-12 Assembly (020,21 S,0-6)... 63-14 BLADE LIFT CYLINDER Removal and Installation............... 63-16 BLADE ANGLE CYLINDER Removal and Installation............... 63-16 BLADE TILT CYLINDER Removal and Installation............... 63-1 B BUCKET LIFT CYLINDER Removal and Installation... ;. 63-20 BUCKET DUMP CYLINDER Removal and Installation............... 63-20 HYDRAULIC CYLINDER Disassembly.......................... 63-22 Assembly............................ 63-24 020,21-6 63-1 C~)
HYDRAULIC SYSTEM 64 MAINTENANCE STANDARD Hydraulic control velve (020,21A,E-6, 020, 21 P-SA, B)... 34-2 Hydraulic control valve (020,21 P, PL, PLL-61... ~.... 34-4 Hydraulic control valve (020, 21 S, 0-6, 021 S-6A)... 34-6 Hydraulic cylinder (020, 21 A, E, P-61... 34-8 Hydraulic cylinder (020,21 S, 0-6, 021 S-SA)... 34-10 Hydraulic pump........................... 34-11 020,21-6 64-1
WORK EQUIPMENT 71. STRUCTURE AND FUNCTION Power angle and tiltdozer (020, 21 A, E-6, 020, 21 P-6A, B)....... 71-2 Strainght tiltdozer (020, 21 P, PL, PLL-6)... 71-4 Bucket and link (020,21S,Q-6,021S-6A).71-6 D20,21-6 71-1
WORK EQUIPMENT 73 DISASSEMBLY AND ASSEMBLY WORK EQUIPMENT Removal and Installation... ;.... 73-2 BLADE Removal and Installation... :.... 73-4 WORK EQUIPMENT Removal and Installation...,....... 73-6 BUCKET Removal and Installation................ 73-6 020,21-6 73-1 ~
WORK EQUIPMENT 74 MAINTENANCE STANDARD Power angle and tiltdozer (020,21A,E-6,020, 21P-6A,Bl..... 74-2 5trainghttiltdozer (020, 21 P, PL, PLL-6l... 74-4 Bucket and link (020,215, 0-6, D215-6Al. 74-6 D20,21-6 74-1
ELECTRICAL SYSTEM 81 STRUCTURE AND FUNCTION Wiring dyagram... 81-2 020.21-6 81-1