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Komatsu HD785-7 Shop Manual

Dump truck
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CEBM019012
Shop
Manual
DUMP TRUCK
A10001 & UP
SERIAL NUMBERS
®

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Summary of Contents for Komatsu HD785-7

  • Page 1 CEBM019012 Shop Manual DUMP TRUCK A10001 & UP SERIAL NUMBERS ®...
  • Page 2 Find manuals at https://best-manuals.com...
  • Page 3 SEN01276-12 DUMP TRUCK 1SHOP MANUAL HD785-7 Machine model Serial number HD785-7 A10001 and up 00 Index and foreword Index Composition of shop manual .......................... 2 Table of contents ............................. 4 HD785-7 Find manuals at https://best-manuals.com...
  • Page 4 SEN01771-04 q Testing and adjusting, Part 2 Testing and adjusting, Part 3 SEN01772-03 Testing and adjusting, Part 4 SEN01773-02 Testing and adjusting, Part 5 SEN01774-03 40 Troubleshooting SEN01295-03 Failure code table and fuse locations SEN01936-02 HD785-7 Find manuals at https://best-manuals.com...
  • Page 5 Brake system SEN04642-01 Undercarriage and frame SEN04643-01 Hydraulic system SEN04644-00 Body SEN04645-00 Cab and its attachments SEN04646-00 Electrical system SEN04647-01 90 Diagrams and drawings SEN01297-06 Hydraulic diagrams and drawings SEN01298-03 Electrical diagrams and drawings SEN01299-06 HD785-7 Find manuals at https://best-manuals.com...
  • Page 6 Power train, Part 2 SEN01283-01 Axle ............................. Differential ........................... Final drive............................ Wheels ............................Steering system SEN01284-01 Steering column........................... Steering linkage........................... Brake system SEN01285-04 Brake piping ..........................Brake valve..........................Secondary brake valve........................ Accumulator charge valve ......................HD785-7 Find manuals at https://best-manuals.com...
  • Page 7 20 Standard value table Standard service value table SEN01769-01 Standard value table for engine ....................Standard value table for machine....................30 Testing and adjusting Testing and adjusting, Part 1 SEN01770-02 Testing and adjusting tools list ....................HD785-7 Find manuals at https://best-manuals.com...
  • Page 8 Opening ORBCOMM terminal..................... VHMS controller initial setting procedure ..................Precautions for replacing VHMS controller ................. 29 Pm Clinic check sheet ......................... 35 Initial setting of payload meter..................... 39 Setting of payload meter built in VHMS..................40 HD785-7 Find manuals at https://best-manuals.com...
  • Page 9 Failure code [B@BAZG] Abnormal lowering of engine oil pressure: Lowering of oil pressure ... 36 Failure code [B@BAZK] Engine oil: Level too low ..............38 Failure code [B@BCNS] Engine: Overheat ................40 Failure code [B@BCZK] Lowering of radiator coolant: Lowering of level ........42 HD785-7 Find manuals at https://best-manuals.com...
  • Page 10 Excessively high voltage detected ................... 50 Failure code [CB263] Fuel temperature sensor too high (Right bank): Excessively high voltage detected ................... 52 Failure code [CA265] Fuel temperature sensor abnormally low level (Left bank): Low voltage detection ......................54 HD785-7 Find manuals at https://best-manuals.com...
  • Page 11 High voltage detection ......................38 Failure code [CA452] Common rail pressure sensor abnormally low level (Left bank): Abnormally low voltage detection .................... 40 Failure code [CB452] Common rail pressure sensor abnormally low level (Right bank): Abnormally low voltage detection .................... 40 HD785-7...
  • Page 12 Failure code [CB2249] Loss of pressure feed from supply pump (2) (Right bank): Loss of pressure feed detected ....................31 Failure code [CA2555] Intake heater relay voltage low error (Left bank) ........32 Failure code [CA2556] Intake heater relay voltage high error (Left bank)........34 HD785-7...
  • Page 13 Failure code [DBG9KQ] Model selection signal: Abnormal............68 Failure code [DDD7KX] Trouble in travel speed setting switch system: Out of input signal range ......................70 Failure code [DDD8KA] ARSC system switch system: Disconnection ........72 Failure code [DDD8KB] ARSC system switch system: Short circuit ........... 74 HD785-7...
  • Page 14 Failure code [DHP5KY] (or VHMS_LED display: "n5" o "54") Suspension pressure sensor system: Short circuit (Left front) ..........36 Failure code [DHP5KZ] (or VHMS_LED display: "n5" o "53") Suspension pressure sensor system: Disconnection or ground fault (Left front) ....38 HD785-7...
  • Page 15 Disagreement of revolution speed signal ................26 Failure code [DLT4KA] Transmission output shaft speed sensor: Disconnection ....... 28 Failure code [DLT4MA] Transmission output shaft speed sensor: Disconnection ...... 30 Failure code [DUM7KY] Pre-lubrication operation lamp output abnormality: Hot short circuit ..32 HD785-7...
  • Page 16 Failure code [DX12KA] Front brake proportional pressure reducing solenoid valve output circuit: Disconnection .......................... 14 Failure code [DX12KB] Front brake proportional pressure reducing solenoid valve: Short circuit..........................15 Failure code [DX12KY] Front brake proportional pressure reducing solenoid valve: Short circuit to power source line..................... 16 HD785-7...
  • Page 17 Failure code [DXH4KA] 1st clutch solenoid output circuit: Disconnection ........22 Failure code [DXH4KB] 1st clutch solenoid output circuit: Short circuit ........24 Failure code [DXH4KY] 1st clutch solenoid output circuit: Short circuit to power source line..26 Failure code [DXH5KA] 2nd clutch solenoid output circuit: Disconnection ......... 30 HD785-7...
  • Page 18 Troubleshooting of hydraulic and mechanical system (H-mode) SEN01949-01 Contents of troubleshooting table....................H-1 Machine does not start ......................H-2 Machine does not travel smoothly (hunting)................. H-3 Lockup cannot be cancelled ....................H-4 Excessive shock when starting or shifting excessive ............HD785-7...
  • Page 19 Removal and installation of torque converter and transmission assembly ......... 12 Disconnection and connection of torque converter assembly and transmission assembly ..15 Disassembly and assembly of torque converter PTO assembly ..........22 Disassembly and assembly of transmission assembly ............... 35 HD785-7...
  • Page 20 Electrical circuit diagram for outside cab (3/3) ................Electrical circuit diagram for inside cab (1/3)................Electrical circuit diagram for inside cab (2/3)................11 Electrical circuit diagram for inside cab (3/3)................13 Electrical circuit diagram for VHMS (If equipped)................ 15 HD785-7...
  • Page 21 Electrical circuit diagram for ABS (Inside cab) (If equipped) ............19 Electrical circuit diagram for ASR (If equipped) ................21 Air conditioner electrical circuit diagram (If equipped) ..............23 Electrical circuit diagram for auto greasing (If equipped) ............25 Connectors table and arrangement drawing ................27 HD785-7...
  • Page 22 SEN01276-12 00 Index and foreword HD785-7 Dump truck Form No. SEN01276-12 HD785-7...
  • Page 23 SEN01277-04 DUMP TRUCK 1SHOP MANUAL HD785-7 Machine model Serial number A10001 and up HD785-7 00 Index and foreword Foreword and general information Safety notice ..............................2 How to read the shop manual ......................... 7 Explanation of terms for maintenance standard ..................... 9 Handling of electric equipment and hydraulic component ................11...

  • Page 24: Safety Notice

    Proper service and repair are extremely important for safe machine operation. The service and repair techniques recommended by Komatsu and described in this manual are both effective and safe. Some of these techniques require the use of tools specially designed by Komatsu for the specific purpose.
  • Page 25 Operate the hoist or crane slowly to prevent the component from hitting any other part. Do not work with any part still raised by the hoist or crane. HD785-7...
  • Page 26 If you grasp them, your fingers as large as 39.2 kN {4,000 kg}. may be caught. After the wire ropes are stretched, stop the crane and check the condi- tion of the slung load, wire ropes, and pads. HD785-7...
  • Page 27 11) After operating the hoist, do not swing the control switch. 12) Remember the position of the main switch so that you can turn off the power immedi- ately in an emergency. HD785-7...
  • Page 28 When connecting the refrigerant pip- ing, apply compressor oil for refriger- ant (R134a) (DENSO: ND-OIL8, VA L E O T H E R M A L S Y S T E M S : ZXL100PG (equivalent to PAG46)) to its O-rings. HD785-7...
  • Page 29 Engine volume This section explains the method of reproducing, repairing, and replacing parts. Revision and distribution Any additions, revisions, or other change of notices will be sent to KOMATSU distributors. Get the most up-to-date information before you start any work. HD785-7...
  • Page 30 Places where oil, etc. must be drained, and quantity to be drained. Units In this shop manual, the units are indicated with International System of units (SI). For reference, con- ventionally used Gravitational System of units is indicated in parentheses { }. HD785-7...
  • Page 31 The tightness of fit is decided by the toler- ance. Indication of size of rotating shaft and hole and relationship drawing of them Example: Tolerance Standard size Shaft Hole –0.030 +0.046 –0.076 HD785-7...
  • Page 32 If a product is worn to the allowable value, it must be checked or repaired. Since the permissible value is estimated from vari- ous tests or experiences in most cases, however, it must be judged after consider- ing the operating condition and customer's requirement. HD785-7...
  • Page 33 The pins of the male and female connec- tors are in contact at the crimped terminal or soldered portion, but if there is exces- sive force brought to bear on the wiring, the plating at the joint will peel and cause improper connection or breakage. HD785-7...
  • Page 34 If there is oil or water in the com- pressed air, the contacts will become even dirtier, so remove the oil and water from the compressed air com- pletely before cleaning with com- pressed air. HD785-7...
  • Page 35 If the machine is left disassem- bled for a long time, it is particu- larly easy for improper contact to occur, so always cover the con- nector. HD785-7...
  • Page 36 If the connector cannot be cor- rected easily, remove the clamp and adjust the position. If the connector clamp has been removed, be sure to return it to its original position. Check also that there are no loose clamps. HD785-7...
  • Page 37 (2) while moving it up and down until the locks are set normally. Arrow: 1), 2), 3) a Right of figure: Lock (a) is pulled down (not set completely) and lock (b) is set completely. (1): Male connector (2): Female connector (a), (b): Locks HD785-7...
  • Page 38 After completely drying the con- n e c t o r, b l o w i t w i t h c o n ta c t restorer and reassemble. HD785-7...
  • Page 39 If there is any change, there is proba- bly defective contact in that circuit. HD785-7...
  • Page 40 If an oil clean- ing device is used, it is possible to filter out the dirt that has collected during storage, so this is an even more effective method. HD785-7...
  • Page 41 The oil cleaning equipment is used to ) particles that remove the ultra fine (about 3 the filter built in the hydraulic equipment can- not remove, so it is an extremely effective device. HD785-7...
  • Page 42 Even if lock (L2) is pressed, connec- tor (1) cannot be pulled out toward you, if part A does not float. In this case, float part A with a small screw- driver while press lock (L2), and then pull out connector (1) toward you. HD785-7...
  • Page 43 If the lock is on the underside, use flat-head screwdriver [1] since you cannot insert your fingers. While pressing up lock (C) of the connec- tor with flat-head screwdriver [1], pull out connector (3) in the direction of the arrow. HD785-7...
  • Page 44 Insert the connector to the end, while setting its groove. Turn housing (H1) in the direction of the arrow until it “clicks”. Example) Speed sensor of fuel supply pump: G (SUMITOMO-3) a Pull the connector straight up. HD785-7...
  • Page 45 (Nominal No. 3 and below) Insulator Soft polyvinyl chloride automobile Conduc- Annealed copper for elec- Heat-resis- General wiring in extremely tric appliance tant low-volt- –50 to +110 cold district, wiring at high-tem- age wire for Heat-resistant crosslinked perature place Insulator automobile polyethylene HD785-7...
  • Page 46 (mm d (approx.) 10.4 12.0 13.6 Standard – – – – – – – – – Cov- Standard 10.8 11.4 13.0 13.6 16.0 17.6 er D Standard 10.8 11.4 13.0 13.6 16.0 17.6 “f” of nominal No. denotes flexible”. HD785-7...
  • Page 47 – – – Others – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – HD785-7...
  • Page 48 07378-10400 07371-30400 07379-00500 07378-10500 07371-30500 If the part is not under hydraulic pressure, the following corks can be used. Dimensions Nominal Part Number number 07049-00608 07049-00811 07049-01012 07049-01215 07049-01418 11.5 07049-01620 13.5 07049-01822 07049-02025 07049-02228 18.5 07049-02430 07049-02734 22.5 HD785-7...
  • Page 49 If any part is loosened or damaged, retighten or repair it. Fuel system Check the piping for damage, the mounting bolts and nuts for looseness, and the joints for fuel leakage. If any part is loosened or damaged, retighten or repair it. HD785-7...
  • Page 50 If any bolt or nut is loosened, retighten it. Checking muffler function Check the muffler for abnormal sound and sound different from that of a new muffler. If any abnormal sound is heard, repair the muffler, referring to “Troubleshooting” and “Disassembly and assembly”. HD785-7...
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This manual is also suitable for:

A10001