Komatsu HD785-7 Dump Truck Service Manual
2,000 pages · Publication SEN01274-28
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- Models
- HD785-7
- Serial coverage
- 7001 and up
- Manual type
- Service Manual
- Pages
- 2,000
- Publication
- SEN01274-28
- Condition
- Brand new

What's inside
From the manual's own table of contents: 356 sections, 652 entries. See sample pages (PDF, 809 KB)
Show all 356 sections
Accumulator charge valve44 topics
- Accumulator
- Slack adjuster
- Brake, parking brake
- Parking brake solenoid
- Retarder control valve
- Exhaust brake
- Suspension
- Suspension cylinder
- Rear axle support
- Steering and hoist hydraulic piping
- Steering, hoist filter (high pressure circuit)
- Dump body control
- Power ladder system
- Hydraulic tank
- Steering valve
- Crossover relief valve
- Steering cylinder
- Steering control valve
- Hoist valve
- Dump control valve (EPC valve)
- Hydraulic pump
- Auto greasing system
- Hoist cylinder
- ROPS cab
- Air conditioner
- Rear view monitor
- Controller related
- Machine monitor system
- Automatic shift control system
- External power supply heater
- Automatic emergency steering system
- Automatic suspension system
- Retarder control system
- Battery disconnector switch
- Emergency engine stop switch
- Dump control lever
- Ladder control function
- VHMS controller related
- ABS/ASR system
- Komatsu traction control system (KTCS)
- Altitude setting function
- Speed limit function
- Sensors, switches
- Standard value table for engine
Setting and adjusting of devices49 topics
- Special functions of machine monitor (EMMS)
- Opening ORBCOMM terminal
- VHMS controller initial setting procedure
- Precautions for replacing VHMS controller
- Pm Clinic check sheet
- Initial setting of payload meter
- Setting of payload meter built in VHMS
- Failure codes table
- Fuse locations
- Points to remember when troubleshooting
- Sequence of events in troubleshooting
- Check before troubleshooting
- Classification and procedures for troubleshooting
- Contents of troubleshooting table
- Connection table for connector pin numbers
- T-branch box and T-branch adapter table
- Failure code [1500L0] Dual engagement
- Failure code [15B0NX] Transmission oil filter: Clogging
- Failure code [15F0KM] R o F shifting abuse 1: Mistake in operation
- Failure code [15F0MB] R o F shifting abuse 2: Mistake in operation
- Failure code [15F7KM] Forward clutch disk abuse: Mistake in operation or setting
- Failure code [15G0MW] R clutch: Slipping
- Failure code [15G7KM] Reverse clutch disk abuse: Mistake in operation or setting
- Failure code [15H0MW] Hi clutch: Slipping
- Failure code [15J0MW] Lo clutch: Slipping
- Failure code [15K0MW] 1st clutch: Slipping
- Failure code [15L0MW] 2nd clutch: Slipping
- Failure code [15M0MW] 3rd clutch: Slipping
- Failure code [15N0MW] 4th clutch: Slipping
- Failure code [15SBL1] R clutch solenoid: Fill signal is ON when command current is OFF
- Failure code [15SBMA] R clutch solenoid: Malfunction
- Failure code [15SCL1] Hi clutch solenoid: Fill signal is ON when command current is OFF
- Failure code [15SCMA] Hi clutch solenoid: Malfunction
- Failure code [15SDL1] Lo clutch solenoid: Fill signal is ON when command current is OFF
- Failure code [15SDMA] Lo clutch solenoid: Malfunction
- Failure code [15SEL1] 1st clutch solenoid: Fill signal is ON when command current is OFF
- Failure code [15SEMA] 1st clutch solenoid: Malfunction
- Failure code [15SFL1] 2nd clutch solenoid: Fill signal is ON when command current is OFF
- Failure code [15SFMA] 2nd clutch solenoid: Malfunction
- Failure code [15SGL1] 3rd clutch solenoid: Fill signal is ON when command current is OFF
- Failure code [15SGMA] 3rd clutch solenoid: Malfunction
- Failure code [15SHL1] 4th clutch solenoid: Fill signal is ON when command current is OFF
- Failure code [15SHMA] 4th clutch solenoid: Malfunction
- Failure code [15SJMA] Lockup clutch solenoid: Malfunction
- Failure code [2F00KM] Parking brake: Mistake in operation or setting
- Failure code [2G42ZG] Accumulator: Oil pressure reduction (Front)
- Failure code [2G43ZG] Accumulator: Oil pressure reduction (Rear)
- Failure code [989A00] Engine over run prevention command signal: Operating
- Failure code [989D00] Rear section tipping over alarm: Alarm is activated
High voltage detection20 topics
- Excessively high voltage detected
- High voltage detection
- Failure code [CA234] Engine over speed (At left bank only): Excessively high speed
- Excessively low voltage detected
- Low voltage detection
- Failure code [CA271] PCV1 short circuit (Left bank): Short circuit
- Failure code [CB271] PCV1 short circuit (Right bank): Short circuit
- Failure code [CA272] PCV1 disconnection (Left bank): Disconnection
- Failure code [CB272] PCV1 disconnection (Right bank): Disconnection
- Failure code [CA273] PCV2 short circuit (Left bank): Short circuit
- Failure code [CB273] PCV2 short circuit (Right bank): Short circuit
- Failure code [CA274] PCV2 disconnection (Left bank): Disconnection
- Failure code [CB274] PCV2 disconnection (Right bank): Disconnection
- Disconnection, short circuit
- Failure code [CA342] Engine controller data mismatch (Left bank): Mismatch
- Failure code [CB342] Engine controller data mismatch (Right bank): Mismatch
- Failure code [CA351] Abnormal injector drive circuit (Left bank): Abnormal circuit
- Failure code [CB351] Injector drive circuit abnormality (Right bank): Circuit abnormality
- Failure code [CA431] Trouble in idle validation switch
- Failure code [CA432] Idle validation action error
Disconnection/Short circuit42 topics
- Failure code [CA1633] KOMNET abnormality (Left bank): Communication error
- Failure code [CA2185] Throttle sensor supply voltage high error
- Failure code [CA2186] Throttle sensor power supply low error
- Loss of pressure feed detected
- Failure code [CA2555] Intake heater relay voltage low error (Left bank)
- Failure code [CA2556] Intake heater relay voltage high error (Left bank)
- Failure code [D180KA] Preheating relay output system: Disconnection
- Failure code [D180KB] Preheating relay output system: Grounding fault
- Failure code [D180KY] Preheating relay output system: Hot short circuit
- Failure code [D19HKB] Stop lamp relay output system: Short circuit
- Failure code [D1EFKA] Pre-lubrication start relay output system: Disconnection
- Failure code [D1EFKB] Pre-lubrication start relay output system: Grounding fault
- Failure code [D1EFKY] Pre-lubrication start relay output system: Hot short circuit
- Failure code [D1EHKA] Engine start relay output system: Disconnection
- Failure code [D1EHKB] Engine start relay output system: Grounding fault
- Failure code [D1EHKY] Engine start relay output system: Hot short circuit
- Failure code [D1EMKA] Disconnection of Parking Interlock Relay Output Circuit
- Failure code [D1EMKB] Ground Fault of Parking Interlock Relay Output Circuit
- Failure code [D1EMKY] Hot Short of Parking Interlock Relay Output Circuit
- Failure code [D1ENKZ] Failure of Power Ladder Power Supply Relay Output System
- Failure code [D1EPKA] Disconnection of Power Ladder Pump Drive Relay Output Circuit
- Failure code [D1EPKB] Ground Fault of Power Ladder Pump Drive Relay Output Circuit
- Failure code [D1EPKY] Hot Short of Power Ladder Pump Drive Relay Output Circuit
- Failure code [D1EQKA] Disconnection of Power Ladder Buzzer Relay Output Circuit
- Failure code [D1EQKB] Ground Fault of Power Ladder Buzzer Relay Output Circuit
- Failure code [D1EQKY] Hot Short of Power Ladder Buzzer Relay Output Circuit
- Failure code [D1ERKA] Open Circuit in Power Ladder Raise Solenoid Relay Output Circuit
- Failure code [D1ERKB] Ground Fault of Power Ladder Raise Solenoid Relay Output Circuit
- Failure code [D1ERKY] Hot Short in Power Ladder Raise Solenoid Relay Output Circuit
- Failure code [D1ESKA] Open Circuit in Power Ladder Lower Solenoid Relay Output Circuit
- Failure code [D1ESKB] Ground Fault of Power Ladder Lower Solenoid Relay Output Circuit
- Failure code [D1ESKY] Hot Short in Power Ladder Lower Solenoid Relay Output Circuit
- Failure code [DAF9KM] Wrong connection of connector
- Abnormal communication
- Lowering of power supply voltage
- Abnormality in controller
- Power supply voltage too low
- Failure code [DAQ9KQ] Transmission controller: Disagreement of model selection
- Failure code [DAQRKR] Abnormality in CAN communication (Transmission)
- Failure code [DAQRMA] Transmission controller option setting: Malfunction
- Failure code [DB10KT] Retarder controller nonvolatile memory: Abnormality in controller
- Power supply system trouble
Failure code [DGF1KX] Transmission oil temperature sensor: Out of input signal range30 topics
- (Disconnection and short circuit)
- (Ground fault)
- Failure code [DGR6KX] Steering oil temperature sensor: Input signal out of range
- Failure code [DGT1KX] Torque converter oil temperature sensor: Out of input signal range
- Left bank exhaust temperature sensor system (Front): Disconnection
- Left bank exhaust temperature sensor system (Rear): Disconnection
- Left bank exhaust temperature sensor system (Front): Short circuit
- Left bank exhaust temperature sensor system (Rear): Short circuit
- Right bank exhaust temperature sensor system (Front): Disconnection
- Right bank exhaust temperature sensor system (Rear): Disconnection
- Right bank exhaust temperature sensor system (Front): Short circuit
- Right bank exhaust temperature sensor system (Rear): Short circuit
- (Blow-by pressure sensor: Short circuit)
- (Blow-by pressure sensor: Short circuit with power supply line)
- Suspension pressure sensor system: Short circuit (Right front)
- Suspension pressure sensor system: Disconnection or ground fault (Right front)
- Suspension pressure sensor system: Short circuit (Left front)
- Suspension pressure sensor system: Disconnection or ground fault (Left front)
- Failure code [DHP6KA] Suspension pressure sensor system: Disconnection (Right rear)
- Out of input signal range (Right rear)
- Suspension pressure sensor system: Short circuit (Right rear)
- Suspension pressure sensor system: Disconnection or ground fault (Right rear)
- Failure code [DHP7KA] Suspension pressure sensor system: Disconnection (Left rear)
- Out of input signal range (Left rear)
- Suspension pressure sensor system: Short circuit (Left rear)
- Suspension pressure sensor system: Disconnection or ground fault (Left rear)
- Failure code [DHT5KX] Torque converter oil pressure sensor: Out of input signal range
- Disagreement of run and stop condition with signal
- Failure code [DHU2KX] Front accumulator oil pressure sensor: Out of input signal range
- Failure code [DHU3KX] Rear accumulator oil pressure sensor: Out of input signal range
Failure code [DW2CKA] Transmission lubrication variable valve output: Disconnection25 topics
- Failure code [DW2CKB] Transmission lubrication variable valve output circuit: Ground fault
- Failure code [DW2CKY] Transmission lubrication variable valve output circuit: Hot short
- Failure code [DW2CL1] Transmission lubrication variable valve: Defective reset
- Failure code [DW2CLH] Transmission lubrication variable valve: Malfunction
- Disconnection or short circuit
- (Disconection/Ground fault/Hot short)
- Failure code [DWNBK4] ASR shut-off valve: Trouble (Valve keeps operating)
- Failure code [DWNBKA] ASR shut-off valve output circuit: Disconnection
- Failure code [DWNBKB] ASR shut-off valve output circuit: Ground fault
- Failure code [DWNBKY] ASR shut-off valve output circuit: Short circuit
- Failure code [DWNBMA] ASR shut-off valve: Trouble (Valve does not operate)
- Failure code [DWNDKZ] Trouble in ABS cut-off valve (Front) system
- Failure code [DWNDMA] Defective ABS cut-off valve (Front)
- Failure code [DWNEKZ] Trouble in ABS cut-off valve (Rear) system
- Failure code [DWNEMA] Defective ABS cut-off valve (Rear)
- Output Circuit
- Out of control
- Disconnection
- Short circuit
- Short circuit to power source line
- Malfunction
- Failure code [DX13KA] Output circuit of hoist EPC valve: Disconnection
- Failure code [DX13KB] Output circuit of hoist EPC valve: Short circuit
- Failure code [DX13KY] Output circuit of hoist EPC valve: Short circuit with power source line
- Trouble (Valve keeps operating)
Failure code [DXH7KB] R clutch solenoid output circuit: Short circuit42 topics
- Failure code [DXH7KY] R clutch solenoid output circuit: Short circuit to power source line
- Failure code [DXHHKA] 4th clutch solenoid output circuit: Disconnection
- Failure code [DXHHKB] 4th clutch solenoid output circuit: Short circuit
- Failure code [DXHHKY] 4th clutch solenoid output circuit: Short circuit to power source line
- (Blow-by pressure: High error)
- Left front exhaust temperature sensor (1): Exhaust temperature abnormal rise
- Left rear exhaust temperature sensor (1): Exhaust temperature abnormal rise
- Right front exhaust temperature sensor (1): Exhaust temperature abnormal rise
- Right rear exhaust temperature sensor (1): Exhaust temperature abnormal rise
- Left front exhaust temperature sensor (2): Exhaust temperature abnormal rise
- Left rear exhaust temperature sensor (2): Exhaust temperature abnormal rise
- Right front exhaust temperature sensor (2): Exhaust temperature abnormal rise
- Right rear exhaust temperature sensor (2): Exhaust temperature abnormal rise
- Before troubleshooting of electric system
- Engine does not start
- Automatic preheating does not operate
- Machine monitor does not display all, when starting switch is turned ON
- Machine monitor does not operate when starting switch is OFF
- Alarm buzzer does not sound
- Alarm buzzer does not stop sounding
- do not display properly
- A selection of the display in character display section cannot be changed
- Power mode selecting function does not operate properly
- AISS function does not operate properly
- Seat belt caution lamp does not display properly
- Turn signal lamp or turning lamp (hazard lamp) do not work properly
- Night illumination (lighting) does not work properly
- Emergency steering does not operate
- Hoist lever does not operate normally
- Power supply system (Air conditioner does not operate)
- Compressor and refrigerant system (Air is not cooled)
- Blower motor system (Air does not come out or air flow is abnormal)
- Ladder cannot be lowered with operation switch outside cab
- Ladder cannot be lowered with operation switch inside cab
- Ladder continues lowering
- Ladder cannot be raised with operation switch outside cab
- Ladder continues rising
- Buzzer does not sound when power ladder is operated
- Power ladder pump does not operate
- Machine does not start
- Machine does not travel smoothly (hunting)
- Lockup cannot be cancelled
Disconnection and connection of torque converter assembly and transmission assembly44 topics
- Disassembly and assembly of torque converter and PTO assembly
- Disassembly and assembly of transmission assembly
- Removal and installation of final drive carrier assembly
- Disassembly and assembly of final drive carrier assembly
- Removal and installation of differential assembly
- Disassembly and assembly of differential assembly
- Removal and installation of steering cylinder assembly
- Disassembly and assembly of steering cylinder assembly
- Removal and installation of steering valve assembly
- Disassembly and assembly of steering valve assembly
- Removal and installation of front wheel hub and brake assembly
- Disassembly and assembly of front wheel hub and brake assembly
- Removal and installation of final drive and rear brake assembly
- Disassembly and assembly of final drive and rear brake assembly
- Removal and installation of front wheel assembly
- Removal and installation of rear wheel assembly
- Removal and installation of front suspension cylinder assembly
- Disassembly and assembly of front suspension cylinder assembly (cylinder with buffer ring)
- Removal and installation of king pin
- Removal and installation of rear suspension cylinder assembly
- Disassembly and assembly of rear suspension cylinder assembly
- Removal and installation of hoist valve assembly
- Disassembly and assembly of hoist valve assembly
- Disassembly and assembly of hoist cylinder assembly
- Removal and installation of body assembly
- Disassembly and assembly of operator's seat assembly
- Removal and installation of air conditioner unit assembly
- Removal and installation of engine controller assembly
- Removal and installation of transmission controller assembly
- Removal and installation of retarder controller assembly
- Removal and installation of ABS controller assembly
- Removal and installation of VHMS controller assembly
- Precautions for refrigerant
- Configuration and function of refrigeration cycle
- Outline of refrigeration cycle
- Air conditioner unit
- Air conditioner control panel
- Troubleshooting procedure
- Circuit diagram and arrangement of connector pins
- System diagram
- Details of air conditioner unit
- Inspection by self-diagnosis function
- Testing temperature control system
- Testing vent (mode) changeover
Inside this manual
Real pages from this service manual (2,000 pages). Open the sample pages (PDF, 808 KB)
- Specifications, page 443: 20 Standard value table
- Troubleshooting, page 1,193: Failure code [dGT6KA] (or VHMS_LED display: "n3" o "26") Right bank
- Diagram, page 1,433: Failure code [DX24KB] Ground fault in ABS control valve output circuit
- Foldout diagram, page 1,986: Electrical circuit diagram for inside cab (2/3)
Other manuals for this machine
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This is a service manual
Here's how it compares to the other manual types.
Service manual
Factory repair procedures and technical information such as specifications, troubleshooting, and wiring and hydraulic diagrams, for the models and systems the manual covers. See What's inside for its topics.
Operator's manual
Safe operation, controls, maintenance schedules, lubrication points, inspections, and basic checks. Repair procedures are in the service manual.
Parts manual
Illustrated diagrams with factory part numbers for identifying components and ordering parts. Repair procedures are in the service manual.
Engine service manuals are sometimes sold separately, since certain machine models were offered with more than one engine option.
What it's used for
Factory manual for in-house farm and construction shop use. Straightforward, complete, and easy to follow. It contains the OEM information dealership service departments and parts counters use to diagnose problems, identify components, and perform maintenance or repairs correctly.
Service shops and owner/operators who repair their own equipment
Identifying correct parts and seeing how assemblies come apart and go back together
Keeping equipment running with less downtime
Factory manual, 2,000 pages
Quantity one is the manual described above.
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Other editions and similar models
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