Komatsu PC78UU-6 PC78US-6 Hydraulic Excavator Shop Manual PDF

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Komatsu PC78UU-6 PC78US-6 Hydraulic Excavator Shop Manual SEBM025119 – PDF DOWNLOAD

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Komatsu PC78UU-6 PC78US-6 Hydraulic Excavator Shop Manual SEBM025119 – PDF DOWNLOAD 

Language : English
Pages : 1090
Downloadable : Yes
File Type : PDF

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TABLE OF CONTENTS:

Komatsu PC78UU-6 PC78US-6 Hydraulic Excavator Shop Manual SEBM025119 – PDF DOWNLOAD 

MACHINE MODEL        SERIAL NUMBER
PC78UU-6                        22832 and up
PC78US-6                        4001 and up
PC78US-6                        4809 and up (For Norway & EU)

COVER 1
CONTENTS 2
LIST OF REVISED PAGES 3
SAFETY 9
SAFETY NOTICE 9
FOREWORD 11
GENERAL 11
HOW TO READ THE SHOP MANUAL 12
HOISTING INSTRUCTIONS 13
METHOD OF DISASSEMBLING, CONNECTING PUSH-PULL TYPE COUPLER 14
COATING MATERIALS 16
STANDARD TIGHTENING TORQUE 18
ELECTRIC WIRE CODE 21
CONVERSION TABLE 22
UNITS 28
01 GENERAL 29
SPECIFICATION DIMENSIONS DRAWING 30
WORKING RANGE DRAWING 32
SPECIFICATIONS 34
WEIGHT TABLE 46
LIST OF LUBRICANTS AND COOLANT 50
10 STRUCTURE, FUNCTION AND MAINTENANCE STANDARD 51
PTO 52
COOLING SYSTEM 54
POWER TRAIN SYSTEM 56
SWING CIRCLE 58
SWING MACHINERY 60
TRACK FRAME AND IDLER CUSHION 64
IDLER 66
TRACK ROLLER 67
CARRIER ROLLER 69
SPROCKET 70
TRACK SHOE 71
ARRANGEMENT OF HYDRAULIC COMPONENTS 76
HYDRAULIC TANK AND OIL FILTER 79
CENTER SWIVEL JOINT 81
TRAVEL MOTOR 83
WORK EQUIPMENT CYLINDER 91
SOLENOID VALVE 96
MULTI-CONTROL VALVE 103
ACCUMULATOR FOR BRAKER 104
HYDRAULIC PUMP 105
CONTROL VALVE 130
CLSS 170
SWING MOTOR 208
WORK EQUIPMENT AND SWING PPC VALVE 216
TRAVEL PPC VALVE 222
OFFSET PPC VALVE (PC78UU-6)
ATTACHMENT PPC VALVE (PC78US-6)
BLADE PPC VALVE (PC78UU, PC78US-6) 226
WORK EQUIPMENT 230
DIMENSIONS OF EACH PART OF WORK EQUIPMENT 236
AIR CONDITIONER PIPING (OPTIONAL) 242
ELECTRIC CONTROL SYSTEM 245
SYSTEM COMPONENTS 302
MONITOR SYSTEM 315
SENSORS 321
20 TESTING AND ADJUSTING 325
STANDARD VALUE TABLE 326
STANDARD VALUE TABLE FOR ENGINE 326
STANDARD VALUE TABLE FOR CHASSIS 329
STANDARD VALUE TABLE FOR ELECTRIC PARTS 338
TESTING AND ADJUSTING 349
LIST OF DEVICES FOR TESTING, ADJUSTING, & TROUBLESHOOTING 350
MEASURING ENGINE SPEED 351
MEASURING EXHAUST GAS COLOR 352
ADJUSTING VALVE CLEARANCE 353
MEASURING COMPRESSION PRESSURE 354
MEASURING BLOW-BY PRESSURE 356
TESTING AND ADJUSTING FUEL INJECTION TIMING 358
MEASURING ENGINE OIL PRESSURE 362
ADJUSTING ENGINE STOP SOLENOID 364
ADJUSTING FUEL CONTROL LINKAGE 366
ADJUSTING ENGINE SPEED SENSOR 368
TESTING AND ADJUSTING HYDRAULIC PRESSURE IN WORK EQUIPMENT, SWING, AND TRAVEL CIRCUITS 370
MEASURING LS DIFFERENTIAL PRESSURE AND ADJUSTING LS VALVE 373
ADJUSTING PC VALVE 375
TESTING TVC-EPC SOLENOID OUTPUT PRESSURE 375
MEASURING CONTROL CIRCUIT PRESSURE 378
MEASURING PPC VALVE OUTPUT PRESSURE 379
TESTING SOLENOID VALVE OUTPUT PRESSURE 380
ADJUSTING WORK EQUIPMENT VALVE AND SWING PPC VALVE 382
TESTING TRAVEL DEVIATION 383
TESTING PARTS WHICH CAN CAUSE HYDRAULIC DRIFT OF WORK EQUIPMENT 385
MEASURING OIL LEAKAGE FROM SWING AND TRAVEL MOTORS 386
RELEASING RESIDUAL PRESSURE FROM HYDRAULIC CIRCUIT 387
TESTING CLEARANCE OF SWING CIRCLE BEARING 388
TESTING AND ADJUSTING TRACK SHOE TENSION 389
BLEEDING AIR FROM HYDRAULIC CIRCUIT 390
PROCEDURE FOR ADJUSTING INSTALLATION OF LONG ARM 392
TESTING AND ADJUSTING HOOD CATCH 393
REPLACEMENT PROCEDURE OF POTENTIOMETERS 395
PROCEDURE FOR TESTING DIODE 396
Pm-CLINIC SERVICE 397
TROUBLESHOOTING 401
POINTS TO REMEMBER WHEN TROUBLESHOOTING 402
SEQUENCE OF EVENTS IN TROUBLESHOOTING 403
PRECAUTIONS WHEN CARRYING OUT MAINTENANCE 404
CHECKS BEFORE TROUBLESHOOTING 412
CONNECTOR TYPES AND MOUNTING LOCATIONS (PC78US-6 Serial No : 4001 – 5500) 414
CONNECTOR ARRANGEMENT DIAGRAM (PC78US-6 Serial No : 4001 – 5500) 416
CONNECTOR TYPES AND MOUNTING LOCATIONS (PC78US-6 Serial No : 5501 – 6500) 419
CONNECTOR ARRANGEMENT DIAGRAM (PC78US-6 Serial No : 5501 – 6500) 422
CONNECTOR TYPES AND MOUNTING LOCATIONS (PC78US-6 Serial No : 6501 and up) 425
CONNECTOR ARRANGEMENT DIAGRAM (PC78US-6 Serial No : 6501 and up) 428
CONNECTOR TYPES AND MOUNTING LOCATIONS (PC78UU-6 Serial No : 22832 – 23500) 431
CONNECTOR ARRANGEMENT DIAGRAM (PC78UU-6 Serial No : 22832 – 23500) 434
CONNECTOR TYPES AND MOUNTING LOCATIONS (PC78UU-6 Serial No : 23501 and up) 437
CONNECTOR ARRANGEMENT DIAGRAM (PC78UU-6 Serial No : 23501 and up) 440
CONNECTION TABLE FOR CONNECTOR PIN NUMBERS 444
EXPLANATION OF FUNCTIONS OF ELECTRIC SYSTEM CONTROL MECHANISM 468
DISPLAY AND SPECIAL FUNCTIONS OF MONITOR PANEL 472
TVC VALVE CURRENT ADJUSTMENT TABLE 491
HOW TO READ JUDGMENT TABLE 493
CONTENTS AND PROCEDURE OF TROUBLESHOOTING 498
TROUBLESHOOTING OF COMMUNICATION SYSTEM (N MODE) 499
N-1 Defective communication 500
TROUBLESHOOTING FOR CONTROLLER (GOVERNOR CONTROL SYSTEM) (E MODE) 503
PRECAUTIONS FOR TROUBLESHOOTING FOR CONTROLLER (GOVERNOR CONTROL SYSTEM) 504
ACTION TAKEN BY CONTROLLER WHEN TROUBLE OCCURS AND PROBLEMS ON MACHINE 506
JUDGMENT TABLE FOR CONTROLLER (GOVERNOR CONTROL SYSTEM) AND ENGINE 512
E-1 Controller power supply is defective (LED of controller is turned off) 516
E-2 [E321] (Short circuit in motor drive relay) is displayed 519
E-3 [E323] (Short circuit in accelerator relay system) is displayed 520
E-4 [E325] (Short circuit in decelerator relay system) is displayed 523
E-5 [E328] (Stall of motor) is displayed 528
E-6 [E227] (Trouble in engine speed sensor) is displayed 534
E-7 [E306] Trouble in governor motor feedback potentiometer is displayed 536
E-8 [E308] Trouble in fuel control dial system is displayed 537
E-9 One-touch slow-down mechanism does not work 539
E-10 Engine does not start 542
a) [E304] Short circuit in engine stop solenoid relay system is displayed 542
b) [E314] Disconnection in engine stop solenoid relay system is displayed 542
c) Engine stop solenoid system 545
d) Starting System 550
E-11 Engine does not stop 557
TROUBLESHOOTING FOR CONTROLLER PUMP CONTROL SYSTEM (C MODE) 561
PRECAUTIONS FOR TROUBLESHOOTING FOR CONTROLLER (PUMP CONTROL SYSTEM) 562
ACTION TAKEN BY CONTROLLER WHEN TROUBLE OCCURS AND PROBLEMS ON MACHINE 564
JUDGEMENT TABLE FOR CONTROLLER (PUMP CONTROL SYSTEM) AND HYDRAULIC EQUIPMENT 570
ELECTRIC CIRCUIT DIAGRAM OF C MODE SYSTEM 574
C-1 [E232] Trouble in TVC-EPC solenoid system 585
C-2 [E233] Trouble in TVC-EPC solenoid system 585
C-3 [E203] Trouble in swing holding brake solenoid system 588
C-4 [E213] Trouble in swing holding brake solenoid system 588
C-5 [E206] Trouble in 2nd travel speed selection solenoid system 591
C-6 [E216] Trouble in 2nd travel speed selection solenoid system 591
C-7 [E403] Trouble in boom angle sensor correction (Only PC78UU-6) 594
C-8 [E406] Trouble in arm angle sensor correction (Only PC78UU-6) 594
C-9 [E411] Trouble in offset boom angle sensor correction (Only PC78UU-6) 594
C-10 [E441] Trouble in interference prevention (front) correction (Only PC78UU-6) 596
C-11 [E442] Trouble in interference prevention (side) correction (Only PC78UU-6) 596
C-12 [E443] Trouble in depth indication correction (Only PC78UU-6) 597
C-13 [E258] Short circuit in 5V system of sensor power supply (Only PC78UU-6) 598
C-14 [E224] Trouble in pump pressure sensor is displayed 601
C-15 [E401] Trouble in boom angle sensor system(Only PC78UU-6) 603
C-16 [E402] Trouble in boom angle sensor system (Only PC78UU-6) 603
C-17 [E404] Trouble in arm angle sensor system(Only PC78UU-6) 604
C-18 [E405] Trouble in arm angle sensor system (Only PC78UU-6) 604
C-19 [E407] Trouble in offset angle sensor system (Only PC78UU-6) 605
C-20 [E408] Trouble in offset angle sensor system (Only PC78UU-6) 605
C-21 [E421] Short circuit in boom raise EPC system is displayed (Only PC78UU-6) 606
C-22 [E422] Disconnection in boom raise EPC system is displayed (Only PC78UU-6) 607
C-23 [E423] Short circuit or grounding fault in arm-in EPC system is displayed (Only PC78UU-6) 608
C-24 [E424] Disconnection in arm-in EPC system is displayed (Only PC78UU-6) 609
C-25 [E425] Short circuit or grounding fault in offset left EPC system is displayed (Only PC78UU-6) 610
C-26 [E426] Disconnection in offset left EPC system is displayed (Only PC78UU-6) 611
C-27 [E431] Short circuit or grounding fault in PPC basic pressure lock solenoid system is displayed (Only PC78UU-6) 612
C-28 Boom does not stop automatically at normal position but interferes when it is raised (Only PC78UU-6) 615
C-29 Arm does not stop automatically at normal position but interferes when it is moved in (Only PC78UU-6) 616
C-30 Offset does not stop automatically at normal position but interferes when it is moved to left (Only PC78UU-6) 617
C-31 Work equipment stops far or near (Only PC78UU-6) 618
C-32 Buzzer sounds for 7 seconds while emergency work equipment operation switch is not turned ON (Only PC78UU-6) 619
C-33 Boom raise end cushion does not work at all or normally (Only PC78UU-6) 622
C-34 Arm-in end cushion does not work at all or normally (Only PC78UU-6) 623
C-35 Offset end cushion does not work at all or normally (Only PC78UU-6) 624
C-36 Work equipment stops after or before set height (Only PC78UU-6) 625
C-37 When depth display is reset, 0 0 m is not indicated at GL (Only PC78UU-6) 626
C-38 Work equipment still moves after work equipment lock lever is set to LOCK 627
C-39 Machine does not swing 632
C-40 Travel speed does not rise 635
C-41 Gear speed does not change automatically 636
C-42 Trouble in controller power supply system (LED of controller is turned OFF) 636
TROUBLESHOOTING FOR CONTROLLER (INPUT SIGNAL SYSTEM) (F MODE) 637
F-1 Bit pattern 1023-(4) Swing pressure switch does not light up 638
F-2 Bit pattern 1023-(3) Travel pressure switch does not light up 640
F-3 Bit pattern 1023-(6) Boom RAISE pressure switch does not light up 642
F-4 Bit pattern 1023-(5) Arm IN pressure switch does not light up 644
F-5 Bit pattern 1026-(1) Deceleration switch of left knob does not light up 646
F-6 Bit pattern 1026-(4) 2nd travel speed selection switch (pedal) does not light up (US with blade specification and UU) 648
F-7 Bit pattern 1021-(3) Compressor signal does not light up 649
F-8 Bit pattern 1026-(3) Emergency work equipment operation switch does not light up (Only PC78UU-6) 651
TROUBLESHOOTING FOR HYDRAULIC AND MECHANICAL SYSTEMS (H MODE) 653
TABLE OF HYDRAULIC FAILURE MODES AND THEIR CAUSES 656
H-1 Speed or power of 2 or more systems of work equipment (boom, arm, bucket), travel, swing, and blade is low 658
a) Speed or power of work equipment (including blade), travel, and swing systems is low 658
b) Speed or power of all work equipment (excluding blade) and travel is low 659
c) Speed or power of swing and blade is low 659
d) Speed or power of travel and blade is low 660
e) Speed or power of all work equipment (excluding blade) is low 660
f) Speed or power of travel and swing is low 661
g) Speed or power of all work equipment and swing is low 661
H-2 Engine speed lowers extremely or engine stalls 662
H-3 2 or more systems of work equipment (boom, arm, bucket), travel, swing, and blade do not move 664
a) All work equipment (including blade), travel, and swing systems do not move 664
b) All work equipment (excluding blade) and travel systems do not move 665
c) Swing and blade systems do not move 665
d) Travel and blade systems do not move 666
e) All work equipment (excluding blade) does not move 666
H-4 Abnormal sound comes out (from around pump) 667
H-5 Fine controllability or response is low 668
H-6 Hydraulic drift is large (all work equipment and blade) 669
H-7 Boom speed or power is low (other work equipment is normal) 670
a) Boom RAISE speed or power is low 670
b) Boom LOWER speed or power is low 671
H-8 Arm speed or power is low (Other work equipment is normal) 672
a) Arm IN speed or power is low 672
b) Arm OUT speed or power is low 675
H-9 Bucket speed or power is low (Other work equipment is normal) 676
a) Bucket CURL speed or power is low 676
b) Bucket DUMP speed or power is low 677
H-10 Offset speed or power is low (other work equipment is normal) (Only PC78UU-6) 678
a) Offset left speed or power is low 678
b) Offset right speed or power is low 679
H-11 Boom does not move 680
a) Boom does not rise 680
b) Boom does not lower 681
H-12 Arm does not move 682
a) Arm does not move in 682
b) Arm does not move out 683
H-13 Bucket does not move 684
a) Bucket does not curl 684
b) Bucket does not dump 685
H-14 Offset boom does not move (Only PC78UU-6) 686
a) Offset boom left does not move 686
b) Offset boom right does not move 687
H-15 H-16 Hydraulic drift of boom is large 688
H-16 Hydraulic drift of arm is large 688
H-17 Hydraulic drift of bucket is large 689
H-18 Hydraulic drift of offset is large (Only PC78UU-6) 689
a) Hydraulic drift of offset to left is large 689
b) Hydraulic drift of offset to right is large 689
H-19 Time lag is large (When engine speed is low) 690
H-20 Part loaded more moves slower in compound operation of work equipment 690
H-21 Boom RAISE speed is low in compound operation of swing and boom RAISE 691
H-22 Travel speed lowers extremely in compound operation of travel and boom RAISE 691
H-23 Speed is low in compound operation of work equipment relief and swing, work equipment relief and other work equipment 691
H-24 Work equipment does not move or its speed is low in compound operation of travel and work equipment 692
H-25 Travel deviation is large 693
a) Travel deviation is large during ordinary travel 693
b) Travel deviation is large when machine starts (but normal during ordinary travel) 694
H-26 Travel deviation is large in compound operation of travel and swing, travel and work equipment 695
H-27 Travel speed or power is low (Work equipment, swing, and blade operations are normal) 696
H-28 Machine cannot be steered sharply or steering force is insufficient 698
H-29 Travel speed does not change at all or does not change quickly 699
H-30 Machine does not travel 700
H-30 Supplement 701
H-31 Overrun of travel is large 702
H-32 Travel hydraulic drift is large 702
H-33 Fine controllability or response is low 703
H-34 Swing speed or power is low (Work equipment, travel, and blade operations are normal) 704
H-35 Machine does not swing (Work equipment, travel, and blade operations are normal) 707
a) Swing speed or power is low in both directions 707
b) Swing speed or power is low in either direction 708
H-36 Swing acceleration is low 709
a) Swing acceleration is low in both directions 709
b) Swing acceleration is low in either direction 709
H-37 Overrun of swing is large 710
a) Overrun of swing is large in both directions 710
b) Overrun of swing is large in either direction 710
H-38 Large shock is made when machine stops swinging 711
H-39 Large abnormal sound is made when machine stops swinging 711
H-40 Swing hydraulic drift is large 712
H-41 Fine controllability or response of swing is low 713
H-42 Blade speed or power is low (Work equipment, travel, and swing operations are normal) 714
H-43 Blade does not move (Work equipment, travel, and swing operations are normal) 715
a) Blade does not rise 715
b) Blade does not lower 716
H-44 Hydraulic drift of blade is large 717
H-45 Fine controllability or response of blade is low 718
H-46 Monitor panel displays error code and boom RAISE, arm IN, and offset LEFT operations stop just before interference (Only PC78UU-6) 719
H-47 Machine does not stop boom RAISE, arm IN, and offset LEFT operations automatically but interferes (Only PC78UU-6) 719
TROUBLESHOOTING FOR MACHINE MONITOR SYSTEM (M MODE) 721
ACTION TAKEN BY CONTROLLER WHEN TROUBLE OCCURS AND PROBLEMS ON MACHINE 722
ELECTRIC CIRCUIT DIAGRAM OF M MODE SYSTEM 724
M-1 [E101] (Error history data are abnormal) is displayed 730
M-2 [E108] (Engine coolant temperature is 105 °C) is displayed 732
M-3 [E112] (Wiper forward output is shorted) is displayed 732
M-4 [E113] (Wiper reverse output is shorted) is displayed 732
M-5 [E114] (Contact with washer output of 24 V) is displayed 732
M-6 [E115] (Wiper does not start wiping in 10 seconds) is displayed 732
M-7 [E116] (Wiper is not retracted in 10 seconds) is displayed 732
M-8 When starting switch is turned to ON position, monitor panel segments do not light up for 3 seconds 733
a) Monitor panel segments do not light up at all (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22832 and up) 733
b) Some monitor panel segments do not light up (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22832 and up) 733
a) Monitor panel segments do not light up at all (PC78US-6 Serial No : 6501 and up) 734
b) Some monitor panel segments do not light up (PC78US-6 Serial No : 6501 and up) 734
M-9 When starting switch is set to ON position, all monitor panel segments light up but do not go off 735
M-10 While preheating is not executed, “Preheater monitor” lights up 735
M-11 When starting switch is set to ON position and engine is started, basic check items flash 736
a) Alternator system (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22832 and up) 736
a) Alternator system (PC78US-6 Serial No : 6501 and up) 737
b) Engine oil system (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22832 and up) 738
b) Engine oil system (PC78US-6 Serial No : 6501 and up) 739
M-12 When starting switch is set to ON position (but engine is stopped), caution items and emergency stop items (excluding battery and engine oil) flash 740
a) Alternator system (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22832 and up) 740
a) Alternator system (PC78US-6 Serial No : 6501 and up) 741
b) Engine oil pressure sensor system (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22832 and up) 742
b) Engine oil pressure sensor system (PC78US-6 Serial No : 6501 and up) 743
M-13 When starting switch is set to ON position and engine is started, caution items and emergency stop items flash (When there is not abnormality in inspection items and engine before troubleshooting, however) 744
a) “Engine oil” flashes 744
b) “Charge level” flashes 744
c) “Coolant temperature” flashes (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22832 and up) 745
c) “Coolant temperature” flashes (PC78US-6 Serial No : 6501 and up) 746
d) “Fuel level” flashes (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22832 and up) 747
d) “Fuel level” flashes (PC78US-6 Serial No : 6501 and up) 748
M-14 When starting switch is set to ON position (but engine is stopped), buzzer does not sound for 1 second
While caution item is flashing, buzzer does not sound 749
M-15 Monitor plane lamp for nighttime is not turned on (LC display is normal) 751
M-16 Coolant temperature gauge does not rise 753
M-17 Coolant temperature gauge is not displayed (Gauge does not rise to 1st line during operation) 755
M-18 Fuel level gauge always displays full 757
M-19 Fuel level gauge is not displayed 759
M-20 While engine is running, service meter does not advance 761
M-21 Trouble in fuel level sensor 762
M-22 Trouble in coolant temperature sensor 764
M-23 Wiper does not operate or operates while wiper switch is turned off 765
a) Wiper does not operate (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22832 and up) 765
b) Wiper operates while wiper switch is turned off (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22832 and up) 765
a) Wiper does not operate (PC78US-6 Serial No : 6501 and up) 766
b) Wiper operates while wiper switch is turned off (PC78US-6 Serial No : 6501 and up) 766
M-24 Washer motor does not operate or operates while washer switch is turned off 770
a) Washer motor does not operate 770
b) Washer operates while wiper switch is turned off 770
M-25 Depth set 0 mode and height mode cannot be selected and set (Only PC78UU-6) 773
30 DISASSEMBLY AND ASSEMBLY 775
METHOD OF USING MANUAL 776
PRECAUTIONS WHEN CARRYING OUT OPERATION 777
SPECIAL TOOL LIST 781
COUNTERWEIGHT ASSEMBRY 789
REMOVAL (PC78US-2 Serial No : 4001 – 6500 PC78UU-2 Serial No : 22001 and up) 789
INSTALLATION (PC78US-2 Serial No : 4001 – 6500 PC78UU-2 Serial No : 22001 and up) 789
REMOVAL (PC78US-2 Serial No : 6501 and up) 790
INSTALLATION (PC78US-2 Serial No : 6501 and up) 790
INJECTION PUMP ASSEMBLY 791
REMOVAL (PC78US-6 Serial No : 4001 – 5500 PC78UU-6 Serial No : 22001 – 23500) 791
INSTALLATION (PC78US-6 Serial No : 4001 • 5500 PC78UU-6 Serial No : 22001 • 23500) 792
REMOVAL (PC78US-6 Serial No : 5501 and up PC78UU-6 Serial No : 23501 and up) 795
INSTALLATION (PC78US-6 Serial No : 5501 and up PC78UU-6 Serial No : 23501 and up) 796
CYLINDER HEAD ASSEMBLY 799
REMOVAL (PC78US-6 Serial No : 4001 – 5500 PC78UU-6 Serial No : 22001 – 23500) 799
INSTALLATION (PC78US-6 Serial No : 4001 – 5500 PC78UU-6 Serial No : 22001 – 23500) 801
REMOVAL (PC78US-6 Serial No : 5501 and up PC78UU-6 Serial No : 23501 and up) 802
INSTALLATION (PC78US-6 Serial No : 5501 and up PC78UU-6 Serial No : 23501 and up) 805
MAIN PUMP ASSEMBLY 807
REMOVAL 807
INSTALLATION 808
CONTROLL PUMP ASSEMBLY 809
REMOVAL 809
INSTALLATION 809
ENGINE AND MAIN PUMP ASSEMBLY 810
REMOVAL 810
INSTALLATION 812
ENGINE HOOD ASSEMBLY 813
REMOVAL 813
INSTALLATION 813
HYDRAULIC OIL COOLERASSEMBLY 815
REMOVAL (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 815
INSTALLATION (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 815
REMOVAL (PC78US-6 Serial No : 6501 and up) 816
INSTALLATION (PC78US-6 Serial No : 6501 and up) 816
RADIATOR ASSEMBLY 817
REMOVAL (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 817
INSTALLATION (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 817
REMOVAL (PC78US-6 Serial No : 6501 and up) 818
INSTALLATION (PC78US-6 Serial No : 6501 and up) 818
SWING MOTOR AND SWING MACHINERY ASSEMBLY 819
REMOVAL 819
INSTALLATION 819
SWING MACHINERY ASSEMBLY 820
DISASSEMBLY (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 820
ASSEMBLY (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 822
DISASSEMBLY (PC78US-6 Serial No : 6501 and up) 826
ASSEMBLY (PC78US-6 Serial No : 6501 and up) 828
SWING MOTOR ASSEMBLY 830
REMOVAL 830
INSTALLATION 830
CENTER SWIVEL JOINT ASSEMBLY 831
REMOVAL 831
INSTALLATION 831
DISASSEMBLY 832
ASSEMBLY 832
CONTROL VALVE ASSEMBLY 833
REMOVAL 833
INSTALLATION 833
ASSEMBLY 834
WORK EQUIPMENT PPC VALVE ASSEMBLY 835
ASSEMBLY 835
TRAVEL PPC VALVE ASSEMBLY 837
ASSEMBLY 837
HYDRAULIC TANK ASSEMBLY 838
REMOVAL (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 838
INSTALLATION (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 838
REMOVAL (PC78US-6 Serial No : 6501 and up) 839
INSTALLATION (PC78US-6 Serial No : 6501 and up) 840
FUEL TANK ASSEMBLY 841
REMOVAL (PC78US-6 Serial No : 4001 – 4903 PC78UU-6 Serial No : 22001 – 22788) 841
INSTALLATION (PC78US-6 Serial No : 4001 – 4903 PC78UU-6 Serial No : 22001 – 22788) 842
REMOVAL (PC78US-6 Serial No : 4904 – 6500 PC78UU-6 Serial No : 22789 and up) 842
INSTALLATION (PC78US-6 Serial No : 4904 – 6500 PC78UU-6 Serial No : 22789 and up) 844
REMOVAL (PC78US-6 Serial No : 6501 and up) 844
INSTALLATION (PC78US-6 Serial No : 6501 and up) 845
CONTROLLER ASSEMBLY 845
REMOVAL (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 845
INSTALLATION (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 845
INSTALLATION (PC78US-6 Serial No : 6501 and up) 846
MONITOR PANEL ASSEMBLY 846
REMOVAL 846
INSTALLATION 846
AIR CONDITIONER UNIT ASSEMBLY 847
REMOVAL 847
INSTALLATION 848
OPERATOR’S CAB ASSEMBLY 849
REMOVAL 849
INSTALLATION 850
FLOOR FRAME ASSEMBLY 851
REMOVAL 851
INSTALLATION 852
OPERATOR’S CAB GLASS (STUCK GLASS) 853
REMOVAL 854
INSTALLATION 855
FRONT WINDOW ASSEMBLY 863
REMOVAL 863
INSTALLATION 863
REVOLVING FRAME ASSEMBLY 864
REMOVAL (PC78US-6 Serial No : 4001 – 6500 PC78UU-6 Serial No : 22001 and up) 864
REMOVAL (PC78US-6 Serial No : 6501 and up) 865
INSTALLATION 866
SWING CIRCLE ASSEMBLY 867
REMOVAL 867
INSTALLATION 867
WORK EQUIPMENT ASSEMBLY 868
REMOVAL 868
INSTALLATION 870
REMOVAL (PC78UU-6) 871
INSTALLATION (PC78UU-2) 873
FIRST BOOM ASSEMBLY 874
REMOVAL 874
INSTALLATION 876
SECOND BOOM ASSEMBLY 877
REMOVAL 877
INSTALLATION 877
OFFSET BRACKET ASSEMBLY 878
REMOVAL 878
INSTALLATION 879
STEEL SHOE, RUBBER PAD SHOE, ROAD LINER ASSEMBLY 880
EXPANSION 880
INSTALLATION 880
RUBBER SHOE ASSEMBLY 881
REMOVAL 881
INSTALLATION 881
FINAL DRIVE AND TRAVEL MOTOR ASSEMBLY 881
REMOVAL 881
INSTALLATION 882
TRAVEL MOTOR 883
SECTIONAL DRAWING, SINGLE VIEW DRAWING 885
1 SECTIONAL DRAWING OF ASSEMBLY 885
2 SINGLE VIEW DISASSEMBLY DRAWING OF REDUCTION GEAR ASSEMBLY 887
3 PARTS LIST 889
OUTLINE OF MAINTENANCE 892
1 TOOLS 892
2 TIGHTENING TORQUE 897
3 WEIGHT TABLE 897
DISASSEMBLY 898
MAINTENANCE STANDARD 913
ASSEMBLY 915
PERFORMANCE TEST 932
CLEARANCE ADJUSTMENT PARTS DIMENSION TABLE 933
IDLER ASSEMBLY 934
ASSEMBLY 934
RECOIL SPRING ASSEMBLY 936
DISASSEMBLY 936
ASSEMBLY 937
TRACK ROLLER ASSEMBLY 938
DISASSEMBLY 938
ASSEMBLY 939
HYDRAULIC CYLINDER ASSEMBLY 941
DISASSEMBLY 941
ASSEMBLY 942
50 OTHER SPECIFICATIONS 945
PC78US-6 (For Norway & EU) 947
CONTENTS 948
SPECIFICATION DIMENSIONS DRAWING 949
WORKING RANGE DRAWING 950
SPECIFICATIONS 952
WEIGHT TABLE 958
STRUCTURE, FUNCTION, AND MAINTENANCE STANDARD 960
ARRANGEMENT OF HYDRAULIC COMPONENTS 960
SOLENOID VALVE 962
ACCUMULATOR FOR PPC 966
DIMENSIONS OF EACH PART OF WORK EQUIPMENT 968
BOOM HYDRAULIC ANTI-BURST VALVE 970
ELECTRIC CONTROL SYSTEM 977
GENERAL SYSTEM DIAGRAM 978
OVERLOAD ALARM FUNCTION 984
OVERLOAD ALARM PRESSURE SENSOR 985
METER DISPLAY UNIT 986
TROUBLESHOOTING 987
CONNECTOR TYPES AND MOUNTING LOCATIONS 987
CONNECTOR ARRANGEMENT DIAGRAM 990
EXPLANATION OF FUNCTIONS OF ELECTRIC SYSTEM CONTROL MECHANISM 1006
DISPLAY AND SPECIAL FUNCTIONS OF MONITOR PANEL 1009
TROUBLESHOOTING FOR CONTROLLER PUMP CONTROL SYSTEM (C MODE) 1017
PRECAUTIONS FOR TROUBLESHOOTING FOR CONTROLLER (PUMP CONTROL SYSTEM) 1018
ACTION TAKEN BY CONTROLLER WHEN TROUBLE OCCURS AND PROBLEMS ON MACHINE 1020
JUDGEMENT TABLE FOR CONTROLLER (PUMP CONTROL SYSTEM) AND HYDRAULIC EQUIPMENT 1024
ELECTRIC CIRCUIT DIAGRAM OF C MODE SYSTEM 1028
C-1 [E232] Trouble in TVC-EPC solenoid system 1031
C-2 [E233] Trouble in TVC-EPC solenoid system 1031
C-3 [E203] Trouble in swing holding brake solenoid system 1033
C-4 [E213] Trouble in swing holding brake solenoid system 1033
C-5 [E206] Trouble in 2nd travel speed selection solenoid system 1035
C-6 [E216] Trouble in 2nd travel speed selection solenoid system 1035
C-7 [E251] Trouble in boom bottom pressure sensor (overload sensor) system 1037
C-8 [E258] short circuit in 5 V system of sensor power supply 1039
C-9 Work equipment still moves after work equipment lock lever is set to LOCK 1042
C-10 Machine does not swing 1045
C-11 Travel speed does not rise 1047
C-12 Gear speed does not change automatically 1048
C-13 Trouble in controller power supply (LED of controller is turned OFF) 1048
TROUBLESHOOTING FOR MACHINE MONITOR SYSTEM (M MODE) 1049
ELECTRIC CIRCUIT DIAGRAM OF M MODE SYSTEM 1050
M-11 When starting switch is set to ON position and engine is started, basic check items flash 1056
a) Alternator system (Serial No : 4809 – 6500) 1056
a) Alternator system (Serial No : 6501 and up) 1057
b) Engine oil pressure system (Serial No : 4809 – 6500) 1058
b) Engine oil pressure system (Serial No : 6501 and up) 1059
M-12 When starting switch is set to ON position (but engine is stopped), caution items and emergency stop items (excluding battery and engine oil) flash 1060
a) Alternator system (Serial No : 4809 – 6500) 1060
a) Alternator system (Serial No : 6501 and up) 1061
b) Engine oil pressure sensor system (Serial No : 4809 – 6500) 1062
b) Engine oil pressure sensor system (Serial No : 6501 and)up) 1063
90 OTHERS 1065
HYDRAULIC CIRCUIT DIAGRAM 1067
PC78US-6 Serial No : 4001 • 6500 (Blade-less specification) 1067
PC78US-6 Serial No : 6501 and up (Blade-less specification) 1068
PC78US-6 (Additional attachment circuit) 1069
PC78US-6 Serial No : 4001 • 6500 (Blade specification) 1070
PC78US-6 Serial No : 6501 and up (Blade specification) 1071
PC78US-6 Serial No : 4809 – 6500 (Norway & EU specification) 1072
PC78US-6 Serial No : 6501 and up (Norway & EU specification) 1073
PC78UU-6 1074
ELECTRICAL CIRCUIT DIAGRAM 1075
PC78US-6 Serial No : 4001 – 5500 (1/2) 1075
PC78US-6 Serial No : 4001 – 5500 (2/2) 1076
PC78US-6 Serial No : 5501 • 6500 (1/2) 1077
PC78US-6Serial No : 5501 – 6500 (2/2) 1078
PC78US-6 Serial No : 6501 and up (1/2) 1079
PC78US-6 Serial No : 6501 and up (2/2) 1080
PC78US-6 Serial No : 4809 • 5500 (Norway & EU specification) (1/2) 1081
PC78US-6 Serial No : 4809 – 5500 (Norway & EU specification) (2/2) 1082
PC78US-6 Serial No : 5501 • 6500 (Norway & EU specification) (1/2) 1083
PC78US-6 Serial No : 5501 – 6500 (Norway & EU specification) (2/2) 1084
PC78US-6 Serial No : 6501 and up (Norway & EU specification) (1/2) 1085
PC78US-6 Serial No : 6501 and up (Norway & EU specification) (2/2) 1086
PC78UU-6 Serial No : 22832 – 23500 (1/2) 1087
PC78UU-6 Serial No : 22832 – 23500 (2/2) 1088
PC78UU-6 Serial No : 23501 and up (1/2) 1089
PC78UU-6 Serial No : 23501 and up (2/2) 1090

DESCRIPTION:

Komatsu PC78UU-6 PC78US-6 Hydraulic Excavator Shop Manual SEBM025119 – PDF DOWNLOAD 

MACHINE MODEL        SERIAL NUMBER
PC78UU-6                        22832 and up
PC78US-6                        4001 and up
PC78US-6                        4809 and up (For Norway & EU)

GENERAL PRECAUTIONS :

Mistakes in operation are extremely dangerous. Read the OPERATION & MAINTENANCE MANUAL carefully BEFORE operating the machine.

PREPARATIONS FOR WORK:

S.V 26/12/24