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Komatsu HD785-7 Dump Truck Service Manual

2,000 pages · Publication SEN05900-03

$199.85
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Models
HD785-7
Serial coverage
30001 and up
Manual type
Service Manual
Pages
2,000
Publication
SEN05900-03
Condition
Brand new
Komatsu HD785-7 Dump Truck Service Manual, publication SEN05900-03

What's inside

From the manual's own table of contents: 343 sections, 643 entries. See sample pages (PDF, 801 KB)

Composition of shop manual
Safety notice
How to read the shop manual
Explanation of terms for maintenance standard
Handling of hydraulic components
Method of disconnecting and connecting push-pull type coupler
Handling of electric equipment
How to read electric wire code
Precautions when performing work
Standard tightening torque table
List of Abbreviation
Conversion table
Specification drawing
Specifications
Weight table
Fuel, coolant and lubricants
Radiator, brake, torque converter oil cooler, aftercooler, steering, hoist oil cooler
Fuel system
Power train skeleton
Output shaft
Drive shaft
Torque converter and transmission hydraulic piping
Brake cooling oil control valve (BCV)
Torque converter
Show all 343 sections
Torque converter valve
Transmission
Transmission control valve
ECMV
Lubricating oil amount selector valve
Axle
Differential
Final drive
Wheels
Steering column
Steering linkage
Brake piping
Brake valve
Secondary brake valve44 topics
  • Accumulator charge valve
  • 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 system
  • Controller related
  • Machine monitor system
  • Automatic shift control system
  • External power supply heater
  • Automatic emergency steering system
  • Automatic suspension system
  • Retarder control system
  • Dump control lever
  • Ladder control function
  • VHMS controller related
  • ABS/ASR system
  • Altitude setting function
  • Speed limit function
  • Sensors, switches
  • Wheel speed sensor (For ABS/ASR)
  • Fuel feed pump switch
  • Standard value table for engine
Standard value table for machine
Testing and adjusting tools list
Sketch of special tool
Testing engine speed
Testing air supply pressure (boost pressure)
Testing exhaust temperature
Testing exhaust gas color
Adjustment of valve clearance
Testing compression pressure
Testing blow-by pressure
Testing engine oil pressure
Handling of fuel system devices
Releasing residual pressure from fuel system
Testing fuel pressure
Reduced cylinder mode operation
No-injection cranking
Testing leakage-from pressure limiter and return rate from injector
Bleeding air from fuel circuit (Standard spec.)
Bleeding air from fuel circuit (Extra low-grade fuel spec.)
Testing the fuel circuit for leakage
Replacement and adjustment of fan belt
Testing and adjusting alternator belt tension
Testing and adjusting air conditioner compressor belt
Testing torque converter stall speed
Testing power train oil pressure
Adjusting transmission speed sensor
Testing and adjusting brake oil pressure
charging accumulator with nitrogen gas
Testing brake performance
Bleeding air from brake circuit
Bleeding air from ASR circuit (if equipped)
Testing wear of front brake disc
Testing wear of rear brake disc
Method of releasing parking brake in an emergency
Testing and adjusting front suspension cylinder
Testing and adjusting rear suspension cylinder
Testing and adjusting front suspension cylinder (Automatic suspension specification)
Testing and adjusting hydraulic pressure in steering, hoist circuit
Testing and adjusting oil pressure in dump EPC circuit
Air bleeding from steering cylinder
Procedure for raising dump body in emergency
Adjusting body positioner sensor
Handling of high voltage circuit of engine controller
Adjusting transmission controller
Method for emergency escape at electrical system failure
Testing and adjusting ladder potentiometer
Calibration method of ladder position
Setting and adjusting of devices
Special functions of machine monitor (EMMS)51 topics
  • 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
  • Connector list and layout
  • 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
  • Failure code [989X00] Overspeed alarm: Alarm operation
  • Failure code [989Y00] Overload alarm: Speed limit function operation
Failure code [989Z00] Parking Brake Interlock Caution
Failure code [A570NX] Engine oil filter: Clogging
Failure code [AA10NX] Air cleaner element: Clogging
(R terminal signal is present and engine is stopped)
Failure code [AB00MA] Alternator: Malfunction
(Absence of R terminal signal and detection error)
Failure code [B@BAZG] Abnormal lowering of engine oil pressure: Lowering of oil pressure
Failure code [B@BAZK] Engine oil: Level too low
Failure code [B@BCNS] Engine: Overheat
Failure code [B@BCZK] Lowering of radiator coolant: Lowering of level
Failure code [B@BFZK] Lowering of fuel level
Failure code [B@C6NS] Brake cooling oil: Overheating (Front)
Failure code [B@C7NS] Brake cooling oil: Overheating (Rear)
Failure code [B@CENS] Overheating of torque converter oil
Failure code [B@GAZK] Battery electrolyte level: Lowering of level
Failure code [B@JANS] Steering oil: Overheat
Failure code [CA111] Engine controller (Left bank): Internal abnormality
Failure code [CB111] Engine controller (Right bank): Internal abnormality
Abnormal speed sensor signal
Excessively high voltage detected
Excessively low voltage detected
Failure code [CA131] Throttle sensor high error (At left bank only)
Failure code [CA132] Throttle sensor low error (At left bank only)
Low voltage detection
High voltage detection19 topics
  • Failure code [CA234] Engine over speed (At left bank only): Excessively high speed
  • Excessively low voltage detected
  • Excessively high 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
Abnormally high pressure occurrence
Abnormally low voltage detection
Excessively high pressure detected
In-range error
Loss of pressure feed detected
Failure code [CA689] Abnormal engine Ne speed sensor (Left bank): Abnormal signal
Failure code [CB689] Abnormal engine Ne speed sensor (Right bank): Abnormal signal
Abnormal phase
Failure code [CA757] Loss of all engine controller data (Left bank): Loss of all data
Failure code [CB757] Loss of all engine controller data (Right bank): Loss of all data
Abnormal Bkup signal
Bkup signal error
Communication error
Distinction error
Disconnection/Short circuit44 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 [DAQV00] Neutral coast prevention control actuation caution: Caution actuated
  • Failure code [DAQW00] Neutral coast state caution: Caution actuated
  • Failure code [DB10KT] Retarder controller nonvolatile memory: Abnormality in controller
  • Power supply system trouble
Power supply voltage too low
Failure code [DB19KQ] Disagreement of model selection (Retarder controller)
Failure code [DB1RKR] CAN communication (retarder controller): Communication disabled
Failure code [DB1RMA] Disagreement of option setting (Retarder controller)
Failure code [DB2RKR] CAN communication (engine controller): Communication disabled
Failure code [DBB0KK] or VHMS_LED display: "n9" o "01
Disagreement of model selection signals
battery power supply: Low power supply voltage (input)
V power supply output: Low output voltage
CAN communication: Defective communication (Abnormality in target component system)
Failure code [DBBRKR] Abnormality in CAN communication (VHMS)
Failure code [DBC0KT] Abnormality of Non-volatile Memory
Failure code [DBC2KK] ABS controller solenoid power supply: Power supply system trouble
Failure code [DBC2KK] Solenoid Power Supply: Low Voltage
Failure code [DBC3KK] Direct Battery Power Supply: Low Voltage
Failure code [DBC9KQ] Disagreement of model selection (ABS controller)
Failure code [DBCRKR] Abnormality in CAN communication (ABS)
Failure code [DBCRMA] Disagreement of option setting (ABS controller)
Failure code [DBG2KK] Solenoid power supply: Low voltage
Failure code [DBG3KK] Battery direct power supply: Low voltage
Failure code [DBG9KQ] Model selection signal: Abnormal
Out of input signal range
Failure code [DDD8KA] ARSC system switch system: Disconnection (If equipped)
Failure code [DDD8KB] ARSC system switch system: Short circuit (If equipped)
Failure code [DDD9KA] ABS system switch system: Disconnection
Failure code [DDD9KB] ABS system switch system: Short circuit
Failure code [DDDAKA] ASR system switch: Disconnection
Failure code [DDDAKB] ASR system switch: Short circuit
Failure code [DDDGL4] Failure of ladder manual operation switch CH1 (inside cab) system
Failure code [DDDHL4] Failure of ladder manual operation switch CH2 (outside cab) system
Failure code [DDE2KB] Engine oil pressure switch error: Grounding fault
Failure code [DDE2L6] Engine oil pressure switch error: Disconnection or hot short circuit
Failure code [DDP6L4] Service brake pressure switch trouble (Rear)
Failure code [DDTHKA] Hi clutch fill switch: Disconnection
Failure code [DDTJKA] Lo clutch fill switch: Disconnection
Failure code [DDTKKA] 1st clutch fill switch: Disconnection
Failure code [DDTLKA] 2nd clutch fill switch: Disconnection
Failure code [DDTMKA] 3rd clutch fill switch: Disconnection
Failure code [DDTNKA] R clutch fill switch: Disconnection
Failure code [DDTPKA] 4th clutch fill switch: Disconnection
Failure code [DDU1KA] Open Circuit in Parking Brake Operation Input Circuit
Failure code [DF10KA] Gear shift lever: Disconnection
Failure code [DF10KB] Gear shift lever: Short circuit
Failure code [DGE5KX] or VHMS_LED display: "n4" o "01
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 [DHU6KX] Trouble in ABS control valve pressure sensor (Front right)
Failure code [DHU7KX] Trouble in ABS control valve pressure sensor (Front left)
Failure code [DHU8KX] Trouble in ABS control valve pressure sensor (Rear right)
Failure code [DHU9KX] Trouble in ABS control valve pressure sensor (Rear left)
Failure code [DJF1KA] Fuel level sensor: Disconnection
Failure code [DK30KX] Steering angle potentiometer: Trouble (Disconnection)
Failure code [DK51L5] Trouble in retarder lever potentiometer and RVS
Failure code [DK52KX] Failure in hoist lever potentiometer 1: Out of input signal range
Failure code [DK53L8] Failure in hoist lever potentiometer 2: Disagreement of analog signal
Failure code [DK54KX] Body positioner sensor: Out of input signal range
Failure code [DK5VKX] Abnormality of Power Ladder Position Input Signal (Out of Range)
Failure code [DK5VMA] Power Ladder System Abnormality
Failure code [DKD0L6] Failure in steering speed sensor
Failure code [DKH0KX] Clinometer sensor signal out of range
Failure code [DLF1KA] Transmission input shaft speed sensor: Disconnection
Disagreement of revolution speed signal
Failure code [DLF2KA] Transmission intermediate shaft speed sensor: Disconnection
Failure code [DLF6KA] Disconnection in wheel speed sensor (Front right)
Failure code [DLF6L3] Trouble in wheel speed sensor (Front right)
Failure code [DLF7KA] Disconnection in wheel speed sensor (Front left)
Failure code [DLF7L3] Trouble in wheel speed sensor (Front left)
Failure code [DLF8KA] Wheel speed sensor: Disconnection (Rear right)
Failure code [DLF8L3] Wheel speed sensor: Disconnection (Rear right)
Failure code [DLF8LC] Wheel speed sensor: Trouble (Rear right)
Failure code [DLF8MA] Wheel speed sensor: Disconnection (Rear right)
Failure code [DLF9KA] Wheel speed sensor: Disconnection (Rear left)
Failure code [DLF9L3] Wheel speed sensor: Trouble (Rear left)
Failure code [DLF9LC] Wheel speed sensor: Trouble (Rear left)
Failure code [DLF9MA] Wheel speed sensor: Disconnection (Rear left)
Failure code [DLT3KA] Transmission output shaft speed sensor: Disconnection
Failure code [DLT4KA] Transmission output shaft speed sensor: Disconnection
Failure code [DLT4MA] Transmission output shaft speed sensor: Disconnection
Failure code [DUM7KY] Pre-lubrication operation lamp output abnormality: Hot short circuit
Disconnection or grounding fault
Failure code [DUM9KZ] Failure of power ladder indicator system
Failure code [DV00KB] Buzzer output: Short circuit
Failure code [DW2AKA] Main pressure variable valve output: Disconnection
Failure code [DW2AKB] Main pressure variable valve output circuit: Ground fault
Failure code [DW2AKY] Main pressure variable valve output circuit: Hot short
Failure code [DW2AL1] Main pressure variable valve: Defective reset
Failure code [DW2ALH] Main pressure variable valve: Malfunction
Failure code [DW2BKA] Main oil level selector valve output: Disconnection
Failure code [DW2BKB] Main oil level selector valve output circuit: Ground fault
Failure code [DW2BKY] Main oil level selector valve output circuit: Hot short
Failure code [DW2BL1] Main oil level selector valve: Defective reset
Failure code [DW2BLH] Main oil level selector valve: Malfunction
Failure code [DW2CKA] Transmission lubrication variable valve output: Disconnection
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 reset23 topics
  • Failure code [DW2CLH] Transmission lubrication variable valve: Malfunction
  • Disconnection or short circuit
  • (Disconnection/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)
  • Ground fault
Short circuit
Trouble (Valve does not operate)
Trouble (Valve keeps operating)
Disconnection
Ground fault
Failure code [DX21KA] Disconnection in ABS control valve output circuit (Front right)
Failure code [DX21KB] Ground fault in ABS control valve output circuit (Front right)
Failure code [DX21KY] Hot short in ABS control valve output circuit (Front right)
Failure code [DX21MA] Defective ABS control valve (Front right)
Failure code [DX22KA] Disconnection in ABS control valve output circuit (Front left)
Failure code [DX22KB] Ground fault in ABS control valve output circuit (Front left)
Failure code [DX22KY] Hot short in ABS control valve output circuit (Front left)
Failure code [DX22MA] Defective ABS control valve (Front left)
Failure code [DX23KA] Disconnection in ABS control valve output circuit (Rear right)
Failure code [DX23KB] Ground fault in ABS control valve output circuit (Rear right)
Failure code [DX23KY] Hot short in ABS control valve output circuit (Rear right)
Failure code [DX23MA] Defective ABS control valve (Rear right)
Failure code [DX24KA] Disconnection in ABS control valve output circuit (Rear left)
Failure code [DX24KB] Ground fault in ABS control valve output circuit (Rear left)
Failure code [DX24KY] Hot short in ABS control valve output circuit (Rear left)
Failure code [DX24MA] Defective ABS control valve (Rear left)
Failure code [DX25MA] Defective ABS front wheel system control valve
Failure code [DX26MA] Defective ABS rear wheel system control valve
Failure code [DXH1KA] Lockup clutch solenoid output circuit: Disconnection
Failure code [DXH1KB] Lock-up clutch solenoid output circuit: Short circuit
Failure code [DXH2KA] Hi clutch solenoid output circuit: Disconnection
Failure code [DXH2KB] Hi clutch solenoid output circuit: Short circuit
Failure code [DXH2KY] Hi clutch solenoid output circuit: Short circuit to power source line
Failure code [DXH3KA] Lo clutch solenoid output circuit: Disconnection
Failure code [DXH3KB] Lo clutch solenoid output circuit: Short circuit
Failure code [DXH3KY] Lo clutch solenoid output circuit: Short circuit in power source line
Failure code [DXH4KA] 1st clutch solenoid output circuit: Disconnection
Failure code [DXH4KB] 1st clutch solenoid output circuit: Short circuit
Failure code [DXH4KY] 1st clutch solenoid output circuit: Short circuit to power source line
Failure code [DXH5KA] 2nd clutch solenoid output circuit: Disconnection
Failure code [DXH5KB] 2nd clutch solenoid output circuit: Short circuit
Failure code [DXH5KY] 2nd clutch solenoid output circuit: Short circuit in power source line
Failure code [DXH6KA] 3rd clutch solenoid output circuit: Disconnection
Failure code [DXH6KB] 3rd clutch solenoid output circuit: Short circuit
Failure code [DXH6KY] 3rd clutch solenoid output circuit: Short circuit to power source line
Failure code [DXH7KA] R clutch solenoid output circuit: Disconnection
Failure code [DXH7KB] R clutch solenoid output circuit: Short circuit
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 line42 topics
  • (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
  • Excessive shock when starting or shifting excessive
  • Transmission does not shift up
  • Machine lacks power or speed when traveling
  • Time lag is excessive when starting or shifting gear
Torque converter oil temperature is high
Torque converter oil pressure is low
Front brake is ineffective
Rear brake is ineffective
Steering wheel is heavy
Steering wheel does not work
Steering wheel vibrates
Dump body lifting speed is slow
Dump body does not work
Excessive hydraulic drift of dump body
Power ladder does not move or its speed is low
Method of using troubleshooting charts
Starting performance is poor
Engine does not start
Engine does not pick up smoothly
Engine stops during operations
Engine does not rotate smoothly
Engine lacks output (or lacks power)
Exhaust smoke is black (incomplete combustion)
Oil consumption is excessive (or exhaust smoke is blue)
Oil becomes contaminated quickly
Fuel consumption is excessive
Oil is in coolant (or coolant spurts back or coolant level goes down)
Oil pressure drops
Oil level rises (Entry of coolant or fuel)
Coolant temperature becomes too high (overheating)
Abnormal noise is made
Vibration is excessive
How to read this manual
Coating materials list
Special tool list
Sketches of special tools
Removal and installation of fuel supply pump assembly
Removal and installation of fuel injector assembly
Removal and installation of cylinder head assembly
Removal and installation of engine hood assembly
Removal and installation of radiator assembly
Removal and installation of engine assembly
Removal and installation of engine front oil seal
Removal and installation of engine rear oil seal
Removal and installation of front drive shaft
Removal and installation of rear drive shaft
Removal and installation of output shaft assembly
Disassembly and assembly of damper assembly
Removal and installation of torque converter and transmission assembly
Disconnection and connection of torque converter assembly and transmission assembly
Disassembly and assembly of torque converter PTO assembly
Disassembly and assembly of transmission assembly
Removal and installation of final drive carrier assembly
Disassembly and assembly of final drive carrier assembly47 topics
  • 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
  • Testing FRESH/RECIRC air changeover
  • Check evaporator temperature sensor
  • Testing relays
  • Troubleshooting chart 1
  • Troubleshooting chart 2
  • Information in troubleshooting table
  • Troubleshooting for power supply system (Air conditioner does not operate)
Troubleshooting for compressor and refrigerant system (Air is not cooled)
Troubleshooting for blower motor system (No air comes out or air flow is abnormal)
Troubleshooting for temperature control
Troubleshooting for vent (mode) changeover
Troubleshooting for FRESH/RECIRC air changeover
Troubleshooting with gauge pressure
Connection of service tool
Precautions for disconnecting and connecting hoses and tubes in air conditioner circuit
Handling of compressor oil
Power train hydraulic circuit diagram
Steering and hoist hydraulic circuit diagram
Brake hydraulic circuit diagram
Brake hydraulic circuit diagram (ASR specification)
Brake hydraulic circuit diagram (ABS specification)
Brake hydraulic circuit diagram (ASR and ABS specification)
Hydraulic circuit diagram for power ladder
Electrical circuit diagram for outside cab
Electrical circuit diagram for inside cab
Electrical circuit diagram for ABS (Outside cab) (If equipped)
Electrical circuit diagram for ABS (Inside cab) (If equipped)
Electrical circuit diagram for ASR (If equipped)
Electrical circuit diagram for power ladder
Air conditioner electrical circuit diagram
Electrical circuit diagram for auto greasing (If equipped)
Electrical circuit diagram of external power supply heater

Inside this manual

Real pages from this service manual (2,000 pages). Open the sample pages (PDF, 800 KB)

Sample pages from the Komatsu HD785-7 Dump Truck Service Manual: Diagram, Troubleshooting, Specifications, Foldout diagram
  • Diagram, page 923: Failure code [CB274] PCV2 disconnection (Right bank): Disconnection1
  • Troubleshooting, page 1,013: Failure code [CA2185] Throttle sensor supply voltage high error
  • Specifications, page 1,613: H-7 Time lag is excessive when starting or shifting gear
  • Foldout diagram, page 1,986: Electrical circuit diagram for inside cab (3/8)

Other manuals for this machine

Save 10% on 2 manuals, 15% on 3 or more. Other manuals for the HD785-7 are listed below. Editions cover different serial number ranges: check the serial coverage and tick only the ones that match your machine.

This manual: Service Manual SEN05900-03$199.85
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This is a service manual

Here's how it compares to the other manual types.

This manual

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.

Fast free USA shipping

Ships in 1 business day.

60-day returns

Free if the mistake is ours. A manual ordered in error must come back unopened in its shrink-wrap; you pay return shipping and a 20% restocking fee applies. Return policy

Binder not included

Manuals over about 300 pages may need a standard 3-ring binder, which you can buy locally to keep the pages organized for shop use.

Other editions and similar models

Komatsu HD785-7Service Manual · SEN01274-28 · $199.97

Questions about model, serial number, engine coverage or contents? Contact us before purchasing and we'll help confirm it's the right manual. Please verify the manual type, machine model, serial number range and engine coverage before purchasing: manuals ordered in error carry a 20% restocking fee (return policy).