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SEN05624-05

ENGINE

125E -6 SERIES

SHOP MANUAL

ENGINE 125E-6 SERIES Model

Serial Number

125E-6 SERIES

00 Index and foreword 1 00 Index and foreword

125E-6 SERIES

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00 Index and foreword Index

Index (ALL-0310-001-A-00-A) 00 Index and foreword ....................................................................................................................... 00-1 Index ......................................................................................................................................... 00-2 Foreword, safety and general information ..................................................................................... 00-5 Important safety notice ......................................................................................................... 00-5 How to read the shop manual.............................................................................................. 00-13 Explanation of terms for maintenance standard .................................................................... 00-15 Handling equipment of fuel system devices .......................................................................... 00-17 Handling of intake system parts........................................................................................... 00-18 Handling of hydraulic equipment.......................................................................................... 00-19 Method of disconnecting and connecting of push-pull type coupler ......................................... 00-21 Handling of electrical equipment.......................................................................................... 00-24 How to read electric wire code............................................................................................. 00-32 Precautions when performing operation ............................................................................... 00-35 Standard tightening torque table.......................................................................................... 00-40 List of abbreviation ............................................................................................................. 00-46 Conversion table ................................................................................................................ 00-51 01 Specification................................................................................................................................. 01-1 Table of contents ........................................................................................................................ 01-2 Specifications............................................................................................................................. 01-3 Exhaust gas regulation ......................................................................................................... 01-3 Applicable machines ............................................................................................................ 01-6 Specifications ...................................................................................................................... 01-7 General view ..................................................................................................................... 01-10 Weight table ...................................................................................................................... 01-24 Engine performance curve .................................................................................................. 01-25 10 Structure and function ................................................................................................................... 10-1 Table of contents ........................................................................................................................ 10-2 Components layout..................................................................................................................... 10-3 Components layout drawing.................................................................................................. 10-3 Intake and exhaust system parts .................................................................................................. 10-6 Intake and exhaust system layout drawing ............................................................................. 10-6 Intake and exhaust system circuit diagram ............................................................................. 10-7 Air cleaner ........................................................................................................................... 10-9 KVGT................................................................................................................................ 10-10 Aftercooler......................................................................................................................... 10-16 EGR system piping drawing ................................................................................................ 10-17 EGR system circuit diagram ................................................................................................ 10-19 EGR valve......................................................................................................................... 10-20 EGR cooler........................................................................................................................ 10-22 Mixing connector................................................................................................................ 10-24 KCCV layout drawing ......................................................................................................... 10-25 KCCV ventilator ................................................................................................................. 10-27 KDPF................................................................................................................................ 10-31 Engine main body parts............................................................................................................. 10-35 Cylinder head .................................................................................................................... 10-35 Cylinder block .................................................................................................................... 10-37 Main moving parts.............................................................................................................. 10-39 Vibration damper................................................................................................................ 10-42 Timing gear ....................................................................................................................... 10-43 Front cover ........................................................................................................................ 10-45 Valve system ..................................................................................................................... 10-46 Flywheel and flywheel housing ............................................................................................ 10-49 Lubrication system.................................................................................................................... 10-50 Lubrication system parts layout drawing ............................................................................... 10-50 Lubrication system diagram ................................................................................................ 10-51 Oil pump ........................................................................................................................... 10-52 Boost oil pump ................................................................................................................... 10-53 Oil filter.............................................................................................................................. 10-54

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00 Index and foreword Index

Oil cooler........................................................................................................................... 10-55 Oil cooler thermo-valve....................................................................................................... 10-56 Oil pan .............................................................................................................................. 10-57 Fuel system ............................................................................................................................. 10-58 Fuel system parts layout drawing......................................................................................... 10-58 Fuel system circuit diagram................................................................................................. 10-60 Outline of CRI system......................................................................................................... 10-63 Fuel dozing........................................................................................................................ 10-76 Fuel cooler ........................................................................................................................ 10-79 Pre-filter ............................................................................................................................ 10-80 Main filter .......................................................................................................................... 10-81 Cooling system......................................................................................................................... 10-82 Cooling system parts layout drawing.................................................................................... 10-82 Cooling system circuit diagram............................................................................................ 10-83 Water pump....................................................................................................................... 10-84 Thermostat ........................................................................................................................ 10-85 Electrical equipment.................................................................................................................. 10-87 Alternator .......................................................................................................................... 10-87 Alternator mounting ............................................................................................................ 10-91 Starting motor .................................................................................................................... 10-92 Fuel feed pump.................................................................................................................. 10-96 Fuel feed pump switch........................................................................................................ 10-97 Engine wiring harness ........................................................................................................ 10-98 Engine controller .............................................................................................................. 10-100 Sensor ............................................................................................................................ 10-106 20 Standard value table ..................................................................................................................... 20-1 Table of contents ........................................................................................................................ 20-2 Standard service value table........................................................................................................ 20-3 Standard value table for engine ............................................................................................. 20-3 Running-in standard and performance test standard ............................................................... 20-9 50 Disassembly and assembly ........................................................................................................... 50-1 Table of contents ........................................................................................................................ 50-2 Related information on disassembly and assembly ........................................................................ 50-3 How to read this manual ....................................................................................................... 50-3 Coating materials list ............................................................................................................ 50-5 Special tool list..................................................................................................................... 50-9 Sketch of special tool.......................................................................................................... 50-11 Disassembly and assembly ....................................................................................................... 50-14 General disassembly of engine ........................................................................................... 50-14 General assembly of engine................................................................................................ 50-35 Removal and installation procedure of supply pump as single component............................... 50-80 Engine front oil seal replacement procedure ......................................................................... 50-85 Engine rear oil seal replacement procedure.......................................................................... 50-88 60 Maintenance standard................................................................................................................... 60-1 Table of contents ........................................................................................................................ 60-2 Intake and exhaust system parts .................................................................................................. 60-3 KVGT.................................................................................................................................. 60-3 Engine main body parts............................................................................................................... 60-4 Cylinder head ...................................................................................................................... 60-4 Cylinder block ...................................................................................................................... 60-5 Cylinder liner ....................................................................................................................... 60-7 Crankshaft........................................................................................................................... 60-8 Cam follower and push rod ................................................................................................... 60-9 Piston ............................................................................................................................... 60-11 Connecting rod .................................................................................................................. 60-13 Vibration damper................................................................................................................ 60-15 Timing gear ....................................................................................................................... 60-16 Camshaft .......................................................................................................................... 60-17 Valve and valve guide......................................................................................................... 60-18 125E-6 SERIES

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00 Index and foreword Index

Rocker arm........................................................................................................................ 60-20 Crosshead and guide ......................................................................................................... 60-21 Flywheel............................................................................................................................ 60-22 Lubrication system.................................................................................................................... 60-24 Main relief valve ................................................................................................................. 60-24 Safety valve....................................................................................................................... 60-25 Cooling system......................................................................................................................... 60-26 Oil cooler........................................................................................................................... 60-26 Water pump....................................................................................................................... 60-27 Thermostat ........................................................................................................................ 60-28 Index.................................................................................................................................................................... 1

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00 Index and foreword Foreword, safety and general information

Foreword, safety and general information (ALL-0370-001-A-00-A) Important safety notice • Appropriate servicing and repair are extremely important to ensure safe operation of the machine. The shop manual describes the effective and safe servicing and repair methods recommended by Komatsu. Some of these methods require the use of the special tools designed by Komatsu for the specific purpose. • The symbol mark k is used for such matters that require special cautions during the work. The work indicated by the caution mark should be performed according to the instructions with special attention to the cautions. Should hazardous situation occur or be anticipated during such work, be sure to keep safe first and take every necessary measure. Safety points • Good arrangement • Correct work clothes • Observance of work standard • Practice of making and checking signals • Prohibition of operation and handling by unlicensed workers • Safety check before starting work • Wearing protective goggles (for cleaning or grinding work) • Wearing shielding goggles and protectors (for welding work) • Good physical condition and preparation • Precautions against work which you are not used to or you are used to too much

•

General precautions k Inappropriate handling causes an extreme

danger. Read and understand what is described in the operation and maintenance manual before operating the machine. Read and understand what is described in this manual before starting the work. • Before performing any greasing or repairs, read all the safety labels stuck to the machine. For the locations of the safety labels and detailed explanation of precautions, see the operation and maintenance manual. • Locate a place in the repair workshop to keep the tools and removed parts. Always keep the tools and parts in their correct places. Always keep the work area clean and make sure that there is no dirt, water or oil on the floor. Smoke only in the areas provided for smoking. Never smoke while working. • When performing any work, always wear the safety shoes and helmet. Do not wear loose work cloths, or clothes with buttons missing. 1. Always wear the protective eyeglasses when hitting parts with a hammer. 2. Always wear the protective eyeglasses when grinding parts with a grinder, etc. • When performing any work with 2 or more workers, always agree on the working procedure 125E-6 SERIES

• •

before starting. While working, always keep conversations of the work between your fellow workers and your self on any step of the work. During the work, hang the warning tag of "UNDER WORKING" in the operator's compartment. Only qualified workers must perform the work and operation which require license or qualification. Keep the tools in good condition. And learn the correct way to use the tools, and use the proper ones among them. Before starting the work, thoroughly check the tools, lift truck, service vehicle, etc. If welding repairs is required, always have a trained and experienced welder with good knowledge of welding perform the work. When performing welding work, always wear welding gloves, apron, shielding goggles, cap, etc. Before starting work, warm up your body thoroughly to start work under good condition. Avoid continuing work for long hours and take rests with proper intervals to keep your body in good condition. Take a rest in a specified safe place.

Preparation • Before adding oil or making any repairs, place the machine on a firm and level ground, and apply the parking brake and chock the wheels or tracks to prevent the machine from moving. • Before starting work, lower the work equipment (blade, ripper, bucket, etc.) to the ground. If it is not possible to lower the equipment to the ground, insert the lock pin or use blocks to prevent the work equipment from falling. And be sure to lock all the work equipment control levers and hang a warning tag on them. • When performing the disassembling or assembling work, support the machine securely with blocks, jacks, or stands before starting the work. • Remove all of mud and oil from the steps or other places used to get on and off the machine completely. Always use the handrails, ladders of steps when getting on or off the machine. Never

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00 Index and foreword Foreword, safety and general information

jump on or off the machine. When the scaffold is not provided, use steps or stepladder to secure your footing. Precautions during work • For the machine equipped with the battery disconnect switch, check that the system operating lamp is turned off before starting the work. Then, turn the battery disconnect switch to OFF (Q) position and remove the switch key. For the machine not equipped with the battery disconnect switch, remove the cable from the battery before starting the work. Be sure to remove the negative end (-) of the battery cable first. • Release the remaining pressure in the circuits completely before the work when the parts in the circuits of oil, fuel, coolant and air are disconnected or removed. When the cap of the oil filter, drain plug or oil pressure pickup plug is removed, loose them slowly to prevent the oil from spurting out. • When removing or installing the checking plug or the piping in the fuel circuit, wait 30 seconds or longer after the engine is shut down and start the work after the remaining pressure is released from the fuel circuit. • Immediately after the engine is shut down, the coolant and oil in the circuits are hot. Be careful not to get scalded by the hot coolant and oil. Start the work after checking that the coolant and oil are cooled down sufficiently. • Start the work after the engine is shut down. Be sure to shut down the engine when working on or around the rotating parts in particular. When checking the machine without shutting down the engine (measuring oil pressure, rotational speed, oil or coolant temperature), take extreme care not to get caught in the rotating parts or the working equipment. • The hoist or crane must be used to sling the components weighing 25 kg or heavier. Check the slings (wire rope, nylon sling, chain and hook) for damage before the work. Use the slings with ample capacity and install them to the proper places. 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. • When removing the part which is under internal pressure or reaction force of the spring, always leave 2 bolts in diagonal positions. Loosen those 2 bolts gradually and alternately and release the pressure, then, remove the part. • When removing the part, be careful not to break or damage the electrical wiring. The damaged wiring may cause electrical fires. • When removing piping, prevent the fuel or oil from spilling out. If any fuel or oil drips onto the

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•

• •

•

floor, wipe it off immediately. Fuel or oil on the floor can cause you to slip and can even cause fires. As a general rule, do not use gasoline to wash parts. Do not use gasoline to clean the electrical parts, in particular. Reinstall the parts removed to their original places. Replace the damaged parts and the parts which must not be used with new ones. When installing the hoses and wiring harnesses, be careful that they are not damaged by contacting with other parts when the machine is operated. When connecting the high pressure hoses and tubes, make sure that they are not twisted. The damaged high pressure hoses and tubes are very dangerous when they are installed. So, be extremely careful when connecting the high pressure pipings. In addition, check that their connections are correct. When assembling or installing the parts, be sure to tighten the bolts to the specified torque. When installing the protective parts such as guards, or the parts which vibrate violently or rotate at high speeds, be sure to check that they are installed correctly. When aligning 2 holes, never insert your fingers or hand into the holes. Align the holes with care so that your fingers are not caught in the hole. When measuring hydraulic pressure, check that the measuring tools are correctly installed. Pay attention to safety when removing and installing the tracks of the track type machines. When removing the track, it separates suddenly. The workers should not stand at either end of the track. If the engine is operated for a long time in a closed place which is not ventilated well, you may suffer from gas poisoning. Accordingly, open the windows and doors to ventilate the place well.

Precautions for slinging work and making signals • Only one appointed worker must make signals and co-worker must communicate with each other frequently. The appointed signaler must make specified signals clearly at the place where the signaler is well seen from the operator's seat and where the signaler can see the working condition easily. The signaler must always stand in front of the load and guide the operator safely. 1. Do not stand under the load. 2. Do not step on the load. • Check the slings before starting sling work. • Keep putting on the gloves during sling work. (Put on the leather gloves, if available.)

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00 Index and foreword Foreword, safety and general information

• Measure the weight of the load by the eye and check its center of gravity. • Use the proper sling according to the weight of the load and method of slinging. If too thick wire ropes are used to sling a light load, the load may slip and fall. • Do not sling a load with 1 wire rope only. If do so, the load may rotate or the sling gets loose and the sling may slip off. Install 2 or more wire ropes symmetrically.

a Slinging near the tip of the hook may cause the rope to slip off the hook during hoisting. The strength of the hook is maximum at its central part.

k Slinging with one rope may cause turning

of the load during hoisting, untwisting of the rope, or slipping of the rope from its original slinging position on the load, which can result in a dangerous accident. • Hanging angle must be 60 deg. or smaller as a rule. • When hanging a heavy load (25kg or heavier), the hanging angle of the rope must be narrower than that of the hook. a When slinging a load with 2 ropes or more, the larger the hanging angle is, the larger the tension of each rope. The figure bellow shows the variation of allowable load in kg when hoisting is made with 2 ropes, each of which is allowed to sling up to 9.8 kN {1,000kg} a load vertically, at various hanging angles. When the 2 ropes sling a load vertically, up to 2,000 kg of total weight can be suspended. This weight is reduced to 1,000 kg when the 2 ropes make a hanging angle of 120 deg.. If the 2 ropes sling a 2,000 kg load at a hanging angle of 150 deg., each rope is subjected to a force as large as 4,000 kg.

• Do not use twisted or kinked wire ropes. • When slinging up a load, observe the following. 1. Wind up the rope slowly until the wire rope tensions. When putting your hands on the wire ropes, do not grasp them but press them down from above. If you grasp them, your fingers may be caught. 2. After the wire ropes are stretched, stop the crane and check the condition of the slung load, wire ropes, and pads. 3. If the load is unstable or the wire rope or chains are twisted, lower the load and lift it up again. 4. Do not lift up the load at an angle. • When lowering a load, pay attention to the following. 1. When lifting down a load, stop it temporarily at 30 cm above the floor, and then lower it slowly. 2. Check that the load is stable, and then remove the sling. 3. Remove kinks and dirt from the wire ropes and chains used for the sling work, and put them in the specified place. Precautions for using mobile crane a Read the Operation and Maintenance Manual of the crane carefully in advance and operate the crane safely. Precautions for using overhead traveling crane k The hoist or crane must be used to sling the

• When installing wire ropes to an angular load, apply pads to protect the wire ropes. If the load is slippery, apply proper material to prevent the wire rope from slipping. • Use the specified eye bolts and fix wire ropes, chains, etc. to them with shackles, etc. • Apply wire ropes to the middle part of the hook.

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components weighing 25 kg or heavier. A part weighing 25 kg or heavier in "disassembly and assembly" section is indicated with the symbol of 4 . • Before starting work, check the wire ropes, brake, clutch, controller, rails, over winding prevention device, ground fault circuit interrupter

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00 Index and foreword Foreword, safety and general information

• • • •

• • • • • • • •

•

• •

for electric shock prevention, crane collision prevention device, and energizing warning lamp, and check the following safety items. Be sure not to touch the lifting tool and lifted load directly. Use push-pull sticks or tagline ropes. Observe the signals for sling work. Operate the hoist at a safe place. Be sure to check the directions of the direction indication plate (north, south, east and west) and the operating button. Do not sling a load at an angle. Do not move the crane while the slung load is swinging. Do not raise or lower a load while the crane is moving longitudinally or laterally. Do not drag a sling. When lifting up a load, stop it just after it leaves the ground and check safety, and then lift it up. Consider the travel route in advance and lift up a load to a safe height. Place the control switch in a position where it will not be an obstacle to work and passage. After operating the hoist, do not swing the control switch. Remember the position of the main switch so that you can turn off the power immediately in an emergency. Shut down the main switch when the hoist stops because of a blackout. When turning on a switch which is turned OFF by the ground fault circuit interrupter for electric shock prevention, check that the devices related to that switch are not in operating condition. If you find an obstacle around the hoist, stop the operation. After finishing the work, stop the hoist at the specified position and raise the hook to at least 2 meters above the floor. Do not leave the sling attached to the hook.

Selecting wire ropes • Select adequate ropes depending on the weight of the parts to be hoisted, referring to the table below Wire rope (JIS G3525, 6 x 37 - Type A) (Standard Z twist wire ropes without galvanizing) Nominal diameter of rope mm 10 12 14 16 18 20 25 30 40 50 60

Allowable load kN 8.8 12.7 17.3 22.6 28.6 35.3 55.3 79.6 141.6 221.6 318.3

ton 0.9 1.3 1.7 2.3 2.9 3.6 5.6 8.1 14.4 22.6 32.4

a The allowable load is calculated as one sixth of the breaking load of the rope to be used (safety coefficient: 6). Precautions for disconnecting and connecting hoses and tubes in air conditioner circuit Disconnection k When replacing the air conditioner unit, air

conditioner compressor, condenser or receiver drier, etc., collect the refrigerant (air conditioner gas: R134a) from the air conditioner circuit before disconnecting the air conditioner hoses. a Ask a qualified person for collecting, adding and filling operations of the refrigerant (air conditioner gas: R134a). (Only registered persons can work.) a Never release the refrigerant (air conditioner gas: R134a) to the atmosphere. k If refrigerant gas (air conditioner gas: R134a)

gets in your eyes, you may lose your sight. And if it touches your skin, you may suffer from frostbite. Put on protective eyeglasses, gloves and working clothes with long sleeves while collecting the refrigerant or filling the air conditioner circuit with the refrigerant. • When loosening the nuts fixing air conditioner hoses and tubes, be sure to use 2 wrenches; use one wrench to fix and use the other one to loosen the nut.

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00 Index and foreword Foreword, safety and general information

Connection • When installing the hose for the air conditioner circuit, take care not to allow invasion of dirt, dusts and water into the hose. • Check that the O-rings are fitted to the joints when connecting the air conditioner piping. • Once an O-ring is used, it is deformed and deteriorated. Accordingly, do not reuse it. • When removing the O-rings, use a soft tool so that the piping is not damaged. • Check that the O-ring is not damaged or deteriorated. • Apply compressor oil for refrigerant (R134a) to the O-ring.

For tightening torques, see "Others", "Precautions for disconnection and connection of air conditioner piping".

a However, do not apply oil to the threaded part of a bolt, nut or union. Manufacturer DENSO VALEO THERMAL SYSTEMS SANDEN

Part name ND-OIL8 ZXL100PG (equivalent to PAG46) SP-10

• When tightening nuts of the air conditioner hoses and tubes, be sure to use 2 wrenches. Use one wrench to fix and tighten the nut with the other wrench to the specified torque (Use a torque wrench for tightening). a Example of fitting of O-ring • An O-ring is fitted to every joint of the air conditioner piping.

125E-6 SERIES

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00 Index and foreword Foreword, safety and general information

Fire prevention (ALL-0000-001-K-27-A) Actions if fire occurs (ALL-0000-17A-K-01-A) • Turn the starting switch to OFF position to stop the engine. • Use the handrails and steps to get off the machine. • Do not jump off the machine. You may fall or suffer serious injury. • The fume generated by a fire contains harmful materials which have a bad influence on a human body when they are sucked. Don't breathe a fume. • After a fire, there may be harmful compounds left. If it touches your skin it may have a bad influence on your body. Be sure to wear rubber gloves when handle the materials left after the fire. The material of the gloves, which is recommended is polychloroprene (Neoprene) or polyvinyl chloride (in the lower temperature environment). When wearing cotton-work-gloves, wear rubber gloves under them.

Precautions to prevent fire

(ALL-0000-17B-K-03-A)

• Fire caused by fuel, oil, coolant or window washer fluid Do not bring any flame or fire close to flammable substances such as fuel, oil, coolant or window washer fluid.There is danger that they may catch fire. Always observe the following. • Do not smoke or use any flame near fuel or other flammable substances. • Shut down the engine before adding fuel. • Do not leave the machine when adding fuel or oil. • Tighten all the fuel and oil caps securely. • Be careful not to spill fuel on overheated surfaces or on parts of the electrical system. • After adding fuel or oil, wipe up any spilled fuel or oil. • Put greasy rags and other flammable materials into a safe container to maintain safety at the workplace. • When washing parts with oil, use a nonflammable oil. Do not use diesel oil or gasoline.There is danger that they may catch fire. • Do not weld or use a cutting torch to cut any pipes or tubes that contain flammable liquids. • Determine well-ventilated areas for storing oil and fuel. Keep the oil and fuel in the specified place and do not allow unauthorized persons to enter.

00-10

• When performing grinding or welding work on the machine, move any flammable materials to a safe place before starting.

9 J D 0 1 7 2 0

9 J D 0 1 7 2 1

• Fire caused by accumulation or attachment of flammable material • Remove any dry leaves, chips, pieces of paper, coal dust, or any other flammable materials accumulated or attached to or

125E-6 SERIES

00 Index and foreword Foreword, safety and general information

•

around the engine exhaust manifold, muffler, or battery, or on the undercovers. • To prevent fires from being caught, remove any flammable materials such as dry leaves, chips, pieces of paper, coal dust, or any other flammable materials accumulated around the cooling system (radiator, oil cooler) or on the undercover. Fire coming from electric wiring Short circuits in the electrical system can cause fire. Always observe the following. • Keep all the electric wiring connections clean and securely tightened. • Check the wiring every day for looseness or damage. Reconnect any loose connectors or refasten wiring clamps. Repair or replace any damaged wiring. Fire caused by piping Check that all the clamps for the hoses and tubes, guards, and cushions are securely fixed in position. If they are loose, they may vibrate during operation and rub against other parts. There is danger that this may lead to damage to the hoses and cause high-pressure oil to spurt out, leading to fire and serious personal injury or death. Fire around the machine due to highly heated exhaust gas Some machines are equipped with KDPF (Komatsu Diesel Particulate Filter). KDPF is a system for purifying soot in exhaust gas. Its exhaust gas discharged during purification process (regeneration) can be at higher temperature than that from existing models. Do not bring any flammable material close to the outlet of the exhaust pipe. • When there are thatched houses, dry leaves or pieces of paper near the work site, set the system to disable the regeneration before starting work to prevent fire hazards due to highly heated exhaust gas. See the operation and maintenance manual for the setting procedure. Explosion caused by lighting equipment • When checking fuel, oil, battery electrolyte, or coolant, always use lighting equipment with anti-explosion specifications. • When taking the electrical power for the lighting equipment from the machine itself, follow the instructions in the operation and maintenance manual.

Dispose of waste materials

(ALL-0000-99A-K-02-A)

To prevent pollution, pay full attention to the way to dispose of waste materials. • Always put the oil and coolant drained from the machine in containers. Never drain the oil and 125E-6 SERIES

coolant directly onto the ground or dump into the sewage system, rivers, the sea, or lakes.

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00 Index and foreword Foreword, safety and general information

• Observe the related laws and regulations when disposing of harmful objects such as oil, fuel, coolant, solvent, filters, and batteries.

Some kinds of rubber and plastics may produce poisonous gas harmful to human body when they are burned. • As for rubber, plastics, or parts (hoses, cables, and wiring harnesses, etc.) which contain those materials, ask the industrial waste treatment firms for their disposals in accordance with the local regulations.

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How to read the shop manual

(ALL-0320-010-A-03-A)

(Rev. 2012/10) • Some attachments and optional parts described in this shop manual may not be arranged for certain areas. Contact your Komatsu distributor if one or some of them are required. • Materials and specifications are subject to change without notice. • The shop manuals are available for "Machine part" and "Engine part". For the engine, see the shop manual for the same model of the engine as the one which is mounted on the machine. Composition of shop manual • This shop manual describes the technical information required for the services performed in a workshop. The shop manual is divided into the following chapters for the convenience of use. 00. Index and foreword • This section includes the index, foreword, safety and basic information. 01. Specification • This section explains the specifications of the machine. 10. Structure and function • This section explains the structure and function of the machine. The section of "Structure and function" serves not only to give an understanding for the structure of each component, but also serves as reference material for troubleshooting. 20. Standard value table • The standard values for a new machine and trouble shooting are described. This standard value table is used for testing and adjusting, and determining a failure at troubleshooting. 50. Disassembly and assembly • This section explains the procedures for removing, installing, disassembling, and assembling each part or component and the special tools for the works as well as precautions for doing them safely. In addition, tightening torque, and quantity and weight of coating material, oil, grease, and coolant required for the works are also explained. 60. Maintenance standard • This section describes the maintenance standard values for each component. This section gives the criterion values for each component and required remedy at disassembly or maintenance.

125E-6 SERIES

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00 Index and foreword Foreword, safety and general information

Symbol Important safety and quality portions are marked with the following symbols so that the shop manual is used practically. Symbol

Item

Safety

Caution

Weight

Tightening torque

Coat

Oil, coolant

Drain

Remarks The special safety precautions required for performing work are described. The special technical precautions or other precautions for preserving standards required when performing work are described The weight of part or component and the cautions required when selecting hoisting wire or when working posture is important are indicated. The tightening torques that require special attention during assembly work are indicated. The places to be coated with adhesives, grease, etc. during assembling are indicated. The places where oil, coolant, etc. must be added and the quantity to be added are indicated. Places where oil, coolant, etc. must be drained and the quantity to be drained are indicated.

Unit • In this shop manual, the units are indicated with International System of units (SI). • For reference, Gravitational System of units which is used to be used is indicated in parentheses of { }.

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00 Index and foreword Foreword, safety and general information

Explanation of terms for maintenance standard

(ALL-0330-006-A-01-A)

(Rev. 2012/10) • The chapter of maintenance standard shows judgement criteria to determine the products to be replaced or to be reused. The judgement criteria are described by using the following terms. Standard dimension and tolerance • To be accurate, the finished dimension of a part is slightly different from one to another. • The finished dimension of a part specifies the allowable difference from the standard dimension which is set first. • The dimension set as the standard is called the standard dimension and the range of difference from this standard dimension is called the "tolerance". • An indication example of a standard dimension and tolerance is shown in the following table. (The standard dimension is entered on the left side and the tolerance is entered with a positive or negative symbol on the right side) Example: Standard dimension

Tolerance -0.022 -0.126

120

• The tolerance may be indicated in the text and a table as "standard dimension (upper limit of tolerance/lower limit of tolerance)." Example: 120(-0.022/-0.126) • Usually, the dimension of a hole and the dimension of a shaft to be inserted into the hole are indicated by the same standard dimension and different tolerances of the hole and shaft. The tightness of fit is decided by the tolerance. • An indication example of a shaft and hole is shown in the following table. (The standard dimension is entered on the left side and the tolerance of the shaft is entered with a positive or negative symbol at the center and that of the hole on the right side) Standard dimension 60

Tolerance Shaft -0.030 -0.076

Hole +0.046 0

Standard clearance and standard value • The clearance made when new parts are assembled is called the standard clearance, which is indicated by the range from the minimum clearance to the maximum clearance. • When some parts are repaired, the clearance is generally adjusted to the standard clearance. • The values indicating performance and function of new products or equivalent are called the "standard value", which is indicated by a range or a target value.

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• When some parts are repaired, the value of performance/function is set to the standard value.

Standard interference • When the diameter of a hole of a part shown in the given standard dimension and tolerance table is smaller than that of the shaft to be inserted, the difference between those diameters is called the "interference". • Subtract the maximum dimension of the hole from the minimum dimension of the shaft and call it (A). Subtract the minimum dimension of the hole from the maximum dimension of the shaft and call it (B). The range between (A) and (B) is the "standard interference". • After repairing or replacing some parts, measure the dimension of their hole and shaft and check that the interference is in the standard range. Repair limit and allowable value or allowable dimension • The dimensions of parts change because of the wear or deformation while they are used. When the dimension changes exceeding certain value,

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the parts can not be used any longer. This value is called "repair limit". • If a part is worn to the repair limit, it must be replaced or repaired. • The performance and function of the products lower while they are used. When the value of the performance and function lowers exceeding a certain limit and it influences the operation etc., this value is called the allowable value or allowable dimension. • A product whose dimension is out of the allowable value, must be repaired. However, since the allowable values are generally estimated through various tests or experiences in most cases, the judgement must be made in consideration of the operating condition and customer's requirement. Allowable clearance • Parts can be used until the clearance between them is increased to a certain limit. The limit at which those parts cannot be used is called the "allowable clearance". • If the clearance between the parts exceeds the allowable clearance, they must be replaced or repaired. Allowable interference • The allowable maximum interference between the hole of a part and the shaft of another part to be assembled is called the "allowable interference". • The allowable interference shows the repair limit of the part of smaller tolerance. • The parts whose interferences are out of the allowable interference must be replaced or repaired.

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Handling equipment of fuel system devices

(PC-AD00-2A4-K-00-A)

(Rev. 2012/01) • The common rail fuel injection system (CRI) consists of more precise parts than the parts used in the conventional fuel injection pump and nozzle. If foreign material enters this system, it may cause a failure. Use special care to prevent entry of the foreign material when servicing the fuel system. Use care for working environment • Avoid filter change or repairing the machine in rain or high winds, or at places where there is a lot of dust. Sealing openings • Plug the pipes and the openings of the components which are removed with the caps, tapes, vinyl bags, etc. to prevent foreign material from entering. Never perform repair works under the condition that the openings are left as they are or plugged with cloths as foreign material may enter or environment may be polluted by the oil leaked. Do not discard the waste oil somewhere or other. Hand it over to your customer for disposal, or dispose it by yourself. How to clean parts when dirt is stuck • If any dirt or dust sticks the parts of the fuel system, clean it off thoroughly with clean fuel. Precautions for replacing fuel filter cartridge • Be sure to use the Komatsu genuine fuel filter cartridge. • The common rail fuel injection system (CRI) consists of more precise parts than the parts used in the conventional fuel injection pump and nozzle. In order to prevent foreign material from entering this system, the filter employs a specially high performance of filter element. If a filter element other than the genuine one is used, the fuel system may have a failure. Accordingly, never use such a filter element.

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Handling of intake system parts

(PC220-A900-2A4-K-00-A)

(Rev.2013/10) • The Komatsu Variable Geometry Turbocharger consists of more precise parts (variable mechanism) than the parts used in the conventional turbocharger. If foreign material enters this system, it may cause a failure. Use special care to prevent entry of the foreign material when servicing the air intake system. Be careful of working environment • Avoid the repair work of the machine in rain or strong wind or at the places where there is a lot of dust. Sealing openings • Plug the pipes and the openings of the components which are removed, with the caps, tapes, vinyl bags, etc. to prevent foreign material from entering. Never perform repair works under the condition that the openings are left open or plugged with rag since foreign material may enter.

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Handling of hydraulic equipment

(ALL-C000-2A4-P-01-A)

(Rev. 2012/10) • With the increase in pressure and precision of the hydraulic components, the most common cause of a failure is dirt (foreign material) in the hydraulic circuit. Therefore, the special care must be taken when adding hydraulic oil,or when disassembling or assembling the hydraulic components. Be careful of working environment • Avoid adding hydraulic oil, replacing filters, or repairing the machine in rain or high winds, or at places where there is a lot of dust. Disassembly and maintenance work in the field • When disassembly or maintenance work of the hydraulic is performed in the field, there is danger of dust entering the components. It is also difficult to check the performance of the components after repairs, so it is desirable to use the component exchange service. The disassembly and assembly of the hydraulic components must be performed in the specially arranged dustproof workshop and the performance test of the components must be performed with the special testing equipment.

Plugging of opening (prevention of flowing out of oil) • Plug the pipes and the openings of the components which are removed (when plugs are not prepared, seal with caps, tapes, vinyl bags, etc.) to prevent entry of foreign material and flowing out of oil. Never leave the openings of the pipes and hoses without being covered or plugged with cloth as foreign material may enter them or environment may be polluted by the oil leaked. Do not discard the waste oil somewhere or other. Hand it over to your customer for disposal, or dispose it by yourself.

125E-6 SERIES

Preventing intrusion of foreign materials during refilling operations. • Care must be taken when adding hydraulic oil so that foreign material does not enter. Keep the oil filler port and the area around it, oil supply pump and oil container clean. If an oil cleaning device is used, it is possible to remove the dirt that is collected during storage. It is a surer means.

Replacing hydraulic oil while its temperature is high • When the hydraulic oil is warm, it flows easily. In addition, sludge can also be drained from the circuit together with the oil. So, it is better to change the hydraulic oil while it is warm. When changing the hydraulic oil, the old oil must be drained as much as possible. (Drain the oil not only from the hydraulic tank, but also from the filter housing and the drain plug hole in the circuit.) If the old oil is left in the system, the contaminant and sludge in the oil mix with the new oil and shorten the life of the new hydraulic oil.

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Flushing operations • After disassembling the equipment or when changing the hydraulic oil with new one, flush the system to remove the contaminant and sludge left in the hydraulic circuit as well as the oil which includes them. Normally, flushing is performed twice. Primary flushing is performed by use of the flushing oil and the secondary flushing is performed by use of the specified hydraulic oil.

Cleaning operations • After repairing the hydraulic equipment (pump, control valve, etc.) or when the machine is in operation, perform oil cleaning to remove the sludge or contaminant in the hydraulic oil circuit. The oil cleaning equipment can remove the ultra fine (approximately 3 μm) particles that the filter built in the hydraulic equipment can not remove. So, it is an extremely effective device.

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Method of disconnecting and connecting of push-pull type coupler

(ALL-

C930-001-P-00-A)

(Rev. 2012/01) k Loosen the oil filler cap of the hydraulic tank slowly to release the remaining pressure in the

hydraulic tank. k Even if the remaining pressure is released from the hydraulic tank, some hydraulic oil flows out

when the hose is disconnected. Accordingly, prepare an oil container.

Type 1

(ALL-C930-925-P-01-A)

Disconnection 1. Hold adapter (1) and push hose joint (2) into mating adapter (3). (Fig. 1) a It can be pushed in by approximately 3.5mm. a Do not hold rubber cap portion (4). 2. While pushing hose joint (2) into adapter (3), push rubber cap (4) against adapter (3) until "click" is heard. (Fig. 2) 3. Hold hose adapter (1) or hose (5) and pull it out. (Fig. 3) a Since some hydraulic oil flows out, prepare an oil container.

125E-6 SERIES

Connection 1. Hold hose adapter (1) or hose (5) and insert it in mating adapter (3) aligning them with each other. (Fig. 4) a Do not hold rubber cap part (4). 2. After inserting the hose fitting in the adapter on the other side perfectly, pull it back to check the connecting condition. (Fig. 4) a When the hose fitting is pulled back, the rubber cap will move approximately 3.5mm toward the hose, however, it is not a problem.

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Type 2

(ALL-C930-925-P-02-A)

Disconnection 1. While holding the fitting, push body (7) in straight until sliding prevention ring (6) hits contact surface (a) at the hexagonal part on the male side. (Fig. 6) 2. While keeping the condition of Step 1, turn lever (8) to the right (clockwise). (Fig. 7) 3. While keeping the conditions of Steps 1 and 2, pull out whole body (7) to disconnect it. (Fig. 8)

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Connection 1. While holding the fitting, push body (7) in straight until sliding prevention ring (6) hits contact surface (a) at the hexagonal part on the male side to connect it. (Fig. 9)

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Type 3

(ALL-C930-925-P-03-A)

Disconnection 1. While holding the fitting, push body (9) in straight until sliding prevention ring (8) hits contact surface (b) at the hexagonal portion on the male side. (Fig. 10) 2. While keeping the condition of Step 1, push cover (10) straight until it hits contact surface (b) of the hexagonal portion on the male side. (Fig. 11) 3. While keeping the conditions of Steps 1 and 2, pull out whole body (9) to disconnect it. (Fig. 12)

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Connection 1. While holding the fitting, push body (9) in straight until sliding prevention ring (8) hits contact surface (a) at the hexagonal portion on the male side to connect them. (Fig. 13)

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Handling of electrical equipment

(ALL-E000-2A4-P-01-A)

(Rev. 2012/11) • To maintain the performance of the machine over a long period, and to prevent failures or troubles before they occur, correct "operation", "maintenance and inspection" "troubleshooting", and "repairs" must be performed. This section deals particularly with correct repair procedures for mechatronics components and is aimed at improving the quality of repairs. For this purpose, it describes the working procedures in "Handling of electrical equipment". Precautions for handling electric equipment Handling wiring harnesses and connectors • Wiring harnesses consist of wires connecting one component to another component, connectors used for connecting and disconnecting one wire from another wire, and protectors or tubes used for protecting the wires. • Compared with other electrical components fitted in boxes or cases, wiring harnesses are more likely to be affected by the direct effects of rain water, heat, or vibration. Furthermore, during inspection and repair operations, they are frequently removed and installed again, so they are likely to suffer deformation or damage. For this reason, it is necessary to be extremely careful when handling the wiring harnesses.

Main failures occurring in wiring harness Defective contact of connectors (defective contact between male and female connectors) • Problems with defective contact are likely to occur because the male connector is not properly inserted into the female connector,or because one or both of connectors are deformed or the position is not correctly aligned, or because there is corrosion or oxidization of the contact surfaces. The corroded or oxidized contact surfaces may become shiny again (and contact may become normal) by connecting and disconnecting the connectors approximately 10 times.

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Defective crimping or soldering of connectors • The pins of the male and female connectors are attached to wires by crimping or soldering. If excessive force is applied to the wire, the joining area may become loose, which may result in a defective connection or breakage.

Disconnections in wiring • If the wiring harness is pulled to disconnect the connector, or the components are lifted with a crane while the wiring harness is still connected, or a heavy object hits the wiring harness, the crimping of the connector may separate, or the soldering may be damaged, or the wiring harness may be broken.

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blow it with compressed air and spray it with electrical contact restorer. a When wiping the joint portion of the connector, be careful not to apply excessive force or deform the pins. a If there is oil or water in the compressed air, it causes the contacts to become dirtier. So, remove the oil and water from the compressed air completely before cleaning the connector with the compressed air.

High-pressure water entering connector • The connector is designed to make it difficult for water to enter (drip-proof structure), but if highpressure water is sprayed directly on the connector, water may enter the connector, depending on the direction of the water jet. Accordingly, take care not to spray water over the connector. The connector is designed to prevent water from entering, but once water does enter, it is difficult to drain it. If water should get into the connector, the pins will be short-circuited by the water. So if any water gets in, immediately dry the connector or take other appropriate action before passing electricity through it.

Removing, installing, and drying connectors and wiring harnesses Disconnecting connectors 1. Hold the connectors when disconnecting. • Disconnect connectors by holding the connector bodies. For the connectors held by a screw, loosen the screw fully, then hold the male and female connectors with each hand respectively and pull them apart horizontally. For the connectors with lock stopper, press down the stopper with your thumb and pull the connectors apart. a Never pull the connector with one hand.

Entry of water, mud or dirt when disconnecting a connector • If any water, mud or dirt is stuck to the outside surface of a connector, it can enter inside the connector when the connector is disconnected. Before disconnecting the connector, wipe off any stuck water or dirt by using a piece of dry cloth or blow it with compressed air. Oil, mud or dirt stuck to connector • If any oil or grease is stuck to the connector and an oil film is formed on the mating surface of the male and female pins, the oil prevents electricity from passing through, resulting in defective contact. If any oil or grease, mud or dirt is stuck to the connector, wipe it off with a dry cloth or

125E-6 SERIES

2. When removing from clips • Both of the connector and clip have stoppers, which are engaged with each other when the connector is connected.

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• Check that there is no oil, dirt or water stick to the connector pins (joint portion). • Check that the connector pins are free from deformation, defective contact, corrosion, or damage. • Check that external surfaces of the connectors are free from damage or breakage.

• When removing a connector from a clip, pull the connector in a parallel direction to the clip for removing stoppers. a If the connector is pried up and down or to the right and left, the housing may break.

a If any oil, water or dirt is stuck to the connector, wipe it off with a dry cloth. If any water is inside the connector, warm the connector and the inside of the wiring harness with a dryer. But be careful not to make it too hot as it causes short circuit. a If there is any damage or breakage, replace the connector. 2. Fix the connector securely. • Align the connectors correctly, and fit them securely. For the connectors with the lock stopper, push in the connectors until "click" is heard.

3. Action to take after removing connectors • After removing the connector, cover it with the vinyl bag to prevent entry of dust, dirt,oil or water in the contact portion. a If the machine is left disassembled for a long time, it is particularly easy for improper contact to occur, so always cover the connector.

3. Correct the protrusion of the boot and misalignment of the wiring harness • For connectors fitted with the boot, correct any extrusion of the boot. In addition, if the wiring harness or the clamp is out of the position, put it in its original position. a If the connector cannot be corrected easily, remove the clamp and adjust the position.

Connecting connectors 1. Check the connector visually.

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00 Index and foreword Foreword, safety and general information

• If the connector clamp is removed, be sure to return it to its original position. And check that it is securely installed.

Drying wiring harness • If there is any oil or dirt on the wiring harness, wipe it off with a dry cloth. Avoid washing by using steam. If the wire harness must be washed in water, do not apply high pressure water or steam directly to the wiring harness. If water gets directly on the connector, do as follows. 1. Disconnect the connector and wipe off the water with a dry cloth. a If the connector is to be blown with dry compressed air, there is a risk that oil in the air may cause defective contact of the conditioner, remove oil and water in the air before starting air blow.

Handling of Deutsch connector (DT8-pin, DT12pin) Disconnection 1. While pressing locks (a) and (b) from each side respectively, pull out female connector (2).

2. Dry the inside of the connector with a dryer. If water gets inside the connector, use a dryer to dry the connector.

Connection 1. Push in female connector (2) horizontally until the lock clicks. (Arrow: x) 2. Since locks (a) and (b) may not be set completely, push in female connector (2) with curving movement until the locks are set normally. (Arrow: x, y, and z)

a Hot air from the dryer can be used, but regulate the time to use hot air in order to prevent the connector or related parts from becoming too hot, as it causes deformation or damage to the connector.

a Lock (a) in the figure is pulled down (not set completely), and lock (b) is set completely.

3. Perform a continuity test on the connector. After drying, leave the wiring harness disconnected and perform a continuity test to check for any short circuits between pins caused by water. a After the connector is completely dried, blow the contact restorer and reassemble them. 125E-6 SERIES

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Handling of connectors used on engine

2. While pressing lock (L2), pull out connector (1).

Slide, lock type (FRAMATOME-3, FRAMATOME-2) Disconnection 1. Slide lock (L1) to the right. 2. While pressing lock (L2), pull out connector (1) toward you. a In the case that even if lock (L2) is pressed, connector (1) cannot be pulled out toward you unless part A floats, float part A with a small flat-head screwdriver while pressing lock (L2), and then pull out connector (1) toward you.

a Lock (L2) is located in the back of connector (1).

Connection 1. Insert the connector securely until a click is heard. (FRAMATOME-24) Disconnection 1. Slide down lock (red) (L1).

Connection 1. Insert the connector securely until a click is heard. Pull lock type (PACKARD-2) Disconnection 1. Disconnect the connector (2) by pulling lock (B) (on the wiring harness side) of connector (2) outward.

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Connection 1. Insert the connector securely until a click is heard. Push lock type (BOSCH-3) Disconnection 1. While pressing lock (C), pull out connector (3) in the direction of the arrow.

Connection 1. Insert the connector securely until a click is heard. (AMP-3) Disconnection 1. While pressing lock (E), pull out connector (5) in the direction of the arrow.

• 114 series

Connection • 107 series

1. Insert the connector securely until a click is heard. (SUMITOMO-2) Disconnection 1. While pressing lock (E), pull out connector (5) in the direction of the arrow.

a If the lock is located on the underside, use flat-head screwdriver [1] since you cannot insert your fingers. While pushing up lock (C) of the connector with flat-head screwdriver [1], pull out connector (3) in the direction of the arrow.

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Connection 1. Insert the connector securely until a click is heard.

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(SUMITOMO-3) Disconnection 1. While pressing lock (E), pull out connector (5) in the direction of the arrow. a Pull the connector straight up.

Connection 1. Insert the connector to the end while aligning its grove to the other. 2. Turn housing (H1) in the direction of the arrow until it "clicks". Connection 1. Insert the connector securely until a click is heard. (SUMITOMO-4) Disconnection 1. While pressing lock (D), pull out connector (4) in the direction of the arrow.

Handling controller • The electronic circuits for control including the microcomputers are assembled in the controller. These electronic circuits in the controller must be handled with care as they control the machine. • Do not place objects on top of the controller. Connection 1. Insert the connector securely until a click is heard. Turn-housing type (Round green connector) (CANNON-4) Disconnection 1. Turn housing (H1) in the direction of the arrow. a Unlock the connector by turning housing (H1). When the lock is release the housing is felt tight to turn. 2. Pull out housing (H1) in the direction of the arrow. a Housing (H1) is left on the wiring harness side.

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• Cover the control connectors with tape or a vinyl bag. Never touch the connector contacts. • During rainy weather, do not leave the controller in a place where it is exposed to rain. • Do not place the controller on oil, water, or soil, or in a place that can be heated to a high 125E-6 SERIES

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temperature even for a short period of time. (Place it on a suitable dry stand.)

• Precautions when performing arc welding When performing arc welding on the machine body, disconnect all the wiring harness connectors connected to the controller. Put the arc welding ground to the place close to the welding point. Precautions for troubleshooting electrical circuits • Be sure to turn the starting switch to "OFF" position before disconnecting or connecting the connectors. • Before performing troubleshooting, check all the related connectors for loose connection. a Check the related connectors for their performance by disconnecting and connecting them several times. • Be sure to connect all the disconnected connectors before proceeding to the next step. a If the starting switch is turned to "ON" position with the connectors disconnected, the failure which is not related to the part which is actually failed. • When performing the troubleshooting for the circuit (measurement of voltage, resistance, continuity, current, etc.), shake the related wiring harnesses and connectors several times and check that the multimeter reading does not change. a If there is any value change on the multimeter, there may be a defective contact in the circuit.

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How to read electric wire code

(ALL-E500-030-P-00-A)

(Rev. 2012/10) • In the electrical circuit diagram, material, thickness and color of each electric wire are indicated by symbols. The wire code is helpful in understanding the electrical circuit diagram. Example) AEX 0.85 L: Indicates blue, heat-resistant, low-voltage wire for automobile, having nominal No. of 0.85 Indicates type of wire by symbol. Type, symbol, and material of wire are shown in Table 1. AEX (Since the use of AV and AVS wires depends on size (nominal No.), their symbols are not indicated on the diagram.) Indicates size of wire by nominal No. 0.85 Size (Nominal No.) is shown in Table 2. Indicates color of wire by color code. L Color codes are shown in Table 3. Type, symbol, and material • AV and AVS are different in thickness and outside diameter of the coating. CAVC has a circular compressed conductor. It differs from AV and AVS in the outside diameter of conductor and thickness of the coating. And AEX is similar to AV in thickness and outside diameter of the coating but different from AV and AVS in material of the coating. (Table 1) Type

Symbol

Low-voltage wire for AV automobile Thin-cover low-voltage wire for AVS automobile (Type 1) Thin-cover low-voltage wire for CAVS automobile (Type 2) Heatresistant lowvoltage wire AEX for automobile

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Conductor material

Insulator material

Temperature range (°C) in use

Example of use For large current wiring (nominal No. 5 and above)

Soft polyvinyl chloride

-30 to +60

Annealed copper for electric appliance

General wiring (nominal No. 3 and lower)

For mid- to small-size excavators (nominal No. 1.25 and lower)

Heat-resistant cross linked polyethylene

-50 to +110

General wiring for extremely cold weather specification Wiring at high ambient temperature place

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Dimensions (Table 2)

Coating D

(0.5) 0.75f (0.85) 1.25f (1.25) Nominal No. 0.5f Number of strands/ 20/ 30/ 11/ 50/ 16/ 7/0.32 Diameter of 0.18 0.18 0.32 0.18 0.32 strand Conductor Crosssectional 0.51 0.56 0.76 0.88 1.27 1.29 area (mm2) d (approx.) 1.0 1.2 1.5 AVS Standard 2.0 2.2 2.5 — — — AV Standard AEX

Standard

2.0

2.2

2.7

37/ 0.26

26/ 0.32

58/ 0.26

41/ 0.32

65/ 0.32

1.96

2.09

3.08

3.30

5.23

1.9 2.9 —

2.3 3.5 —

2.4 3.6 —

3.0 — 4.6

3.0

3.1

—

3.8

4.6

Coating D

Nominal No. 8 15 20 30 40 Number of strands/ 50/0.45 84/0.45 41/0.80 70/0.80 85/0.80 Diameter of strand Conductor Crosssectional 7.95 13.36 20.61 35.19 42.73 area (mm2) d (approx.) 3.7 4.8 6.0 8.0 8.6 — — — — — AVS Standard AV Standard 5.5 7.0 8.2 10.8 11.4 10.8

100

108/ 0.80

127/ 0.80

169/ 0.80

217/ 0.80

54.29

63.84

84.96

109.1

9.8 — 13.0

10.4 — 13.6

12.0 — 16.0

13.6 — 17.6

13.0

13.6

16.0

17.6

Nominal No. Number of strands/ Diameter of strand Conductor Crosssectional area (mm2) d (approx.)

0.5f

0.5

0.75f

0.85

1.25f

1.25

—

7/round compression

—

11/round compression

—

16/round compression

—

0.56

—

0.88

—

1.29

—

0.9

—

1.1

—

1.4

—

1.6

—

1.8

—

2.1

Standard

8.2

5.3

CAVS

7.0

Standard

Coating D

AEX

11.4

a "f" of nominal No. denotes "flexible".

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Color codes table (Table 3) Color Code B Br BrB BrR BrW BrY Ch Dg G GB GL Gr GR GW GY L LB Lg LgB LgR

Color of wire Black Brown Brown & Black Brown & Red Brown & White Brown & Yellow Charcoal Dark green Green Green & Black Green & Blue Gray Green & Red Green & White Green & Yellow Blue Blue & Black Light green Light green & Black Light green & Red

Color Code LgW LgY LR LW LY O P R RB RG RL RW RY Sb Y YB YG YL YR YW

Color of wire Light green & White Light green & Yellow Blue & Red Blue & White Blue & Yellow Orange Pink Red Red & Black Red & Green Red & Blue Red & White Red & Yellow Sky Blue Yellow Yellow & Black Yellow & Green Yellow & Blue Yellow & Red Yellow & White

a Remarks: In a color code consisting of 2 colors, the first color is the color of the background and the second color is the color of the marking. Examples) GW means that the background is "Green" and marking is "White". Types of circuits and color codes Type of wire Charge Ground Start Light Instrument Signal Type of circuit Others

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R B R RW Y G L Br Lg O Gr P Sb Dg Ch

WG — — RB YR GW LW BrW LgR — — — — — —

AVS, AV, CAVS — — — — — — RY RG YB YG GR GY LR LY BrR BrY LgY LgB — — — — — — — — — — — —

AEX — — — RL YL GB LB BrB LgW — — — — — —

— — — — YW GL — — — — — — — — —

R B R D Y G L — — — — — — — —

— — — — Gr Br — — — — — — — — —

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Precautions when performing operation

(ALL-1160-927-A-00-A)

(Rev. 2012/11) • When performing "testing and adjusting" of the machine, "removal and installation" and "disassembly and assembly" of the components, observe the following general cautions. Precautions for removal and disassembly work • If the cooling water contains coolant, dispose of it correctly as chemicals. Do not drain it to the sewage rashly. • After disconnecting the hoses or tubes, plug them to prevent dirt or dust from entering. • When draining oil, prepare a container with sufficient capacity. • Check the match marks which indicate the installing position, and put match marks on the places where they seem necessary before removal of the components to prevent any mistake when assembling. • To prevent any excessive force from being applied to the wiring, always hold the connectors when disconnecting the connectors. Do not pull the wires. • Attach the tags to wires and hoses to show their installing positions to prevent any mistake when installing. • Check the number and thickness of the shims, and keep them in a safe place. • When hoisting the components, prepare the slings with sufficient strength. • When using forcing screws to remove any component, tighten the forcing screws uniformly and alternately. • Before removing any component, clean the surrounding area and cover the component to prevent any foreign material from entering after removal. • After disconnecting the piping or removing a pipe joint, install the following plugs. a The O-rings in the table are emergency parts used for disassembly or transportation of the machine. When assembling, confirm the part numbers in the parts book and use the parts conforming to the using condition. Disconnection of face seal type hoses and tubes

Nominal No. 02 03 04 05 06

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Hose side Plug (1) 07376-70210 07376-70315 07376-70422 07376-70522 07376-70628

Pipe joint side Nut (2) 02789-00210 02789-00315 02789-00422 02789-00522 02789-00628

O-ring (3) 02896-11008 02896-11009 02896-11012 02896-11015 02896-11018

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Disconnection of taper seal type hoses and tubes

Nominal No. 02 03 04 05 06 10 12 14

Hose side Plug (1) 07376-50210 07376-50315 07376-50422 07376-50522 07376-50628 07376-51034 07376-51234 07376-51443

Pipe joint side Nut (2) 07222-00210 07222-00312 07222-00414 07222-00515 07222-00616 07222-01018 07222-01219 07222-01422

Disconnection of split flange type hoses and tubes

No- Bolt pitch (mm) Hose side minal a Flange (1) b No. 0737904 38.1 17.5 00400 0737905 42.9 19.8 00500 0737906 47.6 22.2 00640 0737910 52.4 26.2 01044 0737958.7 30.2 01250 12 0737966.7 31.8 01260 0737914 69.9 35.8 01460

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Tube side Split flange Sleeve head O-ring (4) (2) (3) 07371-30400 07378-10400 07000-12021 07371-30500 07378-10500 07000-13022 07371-30640 07378-10600 07000-13025 07371-31049 07378-11000 07000-13032 07371-31255 07378-11200 07000-13038 07371-51260 07378-11210 07000-13038 07371-31465 07378-11400 07000-13048

Bolt (5) 0101080825 0101080830 0737251035 0737251035 0737251035 0101081245 0737251240

Washer (6) 01643-50823 01643-50823 01643-51032 01643-51032 01643-51032 01643-51232 01643-51232

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No- Bolt pitch (mm) Hose side minal a Flange (1) b No. 0737979.4 36.5 01470 0737977.8 42.8 02071 20 0737996.8 44.5 02080 0737924 88.9 50.8 02484 0737930 106.4 62 03010 34

120.6

69.8

130.2

77.8

152.4

Tube side Split flange Sleeve head O-ring (4) (2) (3)

Bolt (5)

07371-51470 07378-11410 07000-13048 07371-32076 07378-12000 07000-12060 07371-52080 07378-12010 07000-12060 07371-12484 07378-12400 07000-12070 07371-13010 07378-13000 07000-12085

07379-03411 07371-13411 07378-13400 07000-12100 0737904012

07371-14012 07378-14000 07000-12110

07379-05011 07371-15011 07378-15000 07000-12135

0101081455 0737251240 0101081865 0737251240 0737251650 0737251650 0737251650 0737251655

Washer (6) 01643-31445 01643-51232 01643-31845 01643-51232 01643-51645 01643-51645 01643-51645 01643-51645

Removal of pipe joints of O-ring boss type

Nominal No. 08 10 12 14 16 18 20 24 30 33 36 42 52

Plug (1) 07040-10807 07040-11007 07040-11209 07040-11409 07040-11612 07040-11812 07040-12012 07040-12412 07041-13012 07040-13316 07041-13612 07040-14220 07040-15223

O-ring (2) 07002-10823 07002-11023 07002-11223 07002-11423 07002-11623 07002-11823 07002-12034 07002-12434 07002-13034 07002-13334 07002-13634 07002-14234 07002-15234

Removal of pipe joints of taper pipe thread type

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Nominal No. 01 02 03 04 06 10 12 14 20

Nominal thread size R 1/ 8 R 1/ 4 R 3/ 8 R 1/ 2 R 3/ 4 R1 R1 1/4 R1 1/2 R2

Plug (1) Square head type (A) 07042-00108 07042-00211 07042-00312 07042-00415 07042-00617 07042-01019 07042-01222 07042-01422 07042-02026

Hexagonal socket head (B) 07043-00108 07043-00211 07043-00312 07043-00415 07043-00617 07043-01019 07043-01222 07043-01422 07043-02026

Precautions for installation and assembly work • Tighten the bolts and nuts (sleeve nuts) to the specified torque (KES), unless otherwise specified. • Install the hoses without twist and interference, and securely fasten the clamps located in-between if they are. • Replace all of the gaskets, O-rings, cotter pins, and lock plates with new parts. • Bend the cotter pins and lock plates securely. • When applying adhesive, clean and degrease the part, and apply 2 to 3 drops of adhesive to the threaded part. • When applying liquid gasket, clean and degrease the surface, and apply it uniformly after making sure that the surface is free from dirt or damage. • Clean all of the parts, and repair any damage, dents, burrs, or rust found on them. • Coat the rotating parts and sliding parts with engine oil. • Coat the surfaces of the press-fitting parts with molybdenum disulfide lubricant (LM-P). • After installing the snap ring, check that the snap ring is settled in the ring groove completely. • When connecting wiring harness connectors, clean the connectors to remove oil, dirt, or water, then connect them securely. • Use the eye bolts with no fatigue and deformation and screw them in securely. Match the directions of the eyes and the hook. • When installing split flanges, tighten the bolts uniformly and alternately to prevent excessive tightening on one side. • As a rule, apply liquid gasket (LG-5) or liquid sealant (LS-2) to the threaded part of each taper male screws which receives pressure. However, if the threaded part is difficult to degrease, you may use a seal tape. • When winding a seal tape onto a right-handed taper male screw, wind it clockwise in the advancing direction of the threads, seeing from the screw end and starting at the third thread. a If you wind the seal tape in the opposite direction, it becomes loose and comes off or its end part is pushed out, and that can cause oil leakage.

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a When the hydraulic cylinder is used for the first time after reassembly of the hydraulic equipment such as the hydraulic cylinder, pump, etc. and piping after removing them for repair, be sure to perform air bleeding of the hydraulic circuit according to the following procedure. 1. Start the engine, and run it at low idle. 2. Repeat the operation to extend and retract each cylinder of the work equipment to approximately 100 mm before the stroke end 4 to 5 times. 3. Operate the hydraulic cylinder 3 to 4 times to the end of its stroke. a After the completion of repair and when operating the machine which is stored long term, perform the air bleeding with the same procedure as the one described above. Precautions at the time of completing work Refilling of coolant, oil and grease • When the coolant is drained, tighten the drain valve securely, then refill the coolant reservoir with the coolant Komatsu recommends to the specified level. Start the engine to circulate the coolant in the piping, and add the coolant to the specified level again. • When the hydraulic components are removed and installed, refill the oil reservoir with the oil Komatsu recommends to the specified level. Start the engine to circulate the oil in the piping, and add the oil to the specified level again. • If the hydraulic piping or hydraulic equipment is removed, be sure to bleed air from the system after rebuilding the parts, by referring to "Testing and adjusting". • Supply the specified amount of grease to the work equipment parts. Testing installed condition of cylinder heads and manifolds • Check the cylinder head and intake and exhaust manifold mountings for looseness. • If any bolt is loose, retighten it. a For the tightening torques, see the "Disassembly and assembly". Testing of engine piping for damage and looseness Check the piping for damage, the mounting bolts and nuts for looseness, and the joints Intake and exhaust for air suction and exhaust gas leakage. system If any part is loosely installed or damaged, retighten the bolts or repair the parts. Check the piping for damage, the mounting bolts and nuts for looseness, and the joints for water leakage. Cooling system If any part is loosely installed or damaged, retighten the bolts or repair the parts. Check the piping for damage, the mounting bolts and nuts for looseness, and the joints for fuel leakage. Fuel system If any part is loosely installed or damaged, retighten the bolts or repair the parts. Check of KDPF or muffler and exhaust pipe for damage and looseness • Visually check the KDPF or muffler, exhaust pipe and their mounting parts for a crack and damage. If any part is damaged, replace it. • Check the mounting bolts, nuts, and clamps of the KDPF or muffler, exhaust pipe and their mounting parts for looseness. If any part is loosely installed, retighten the bolts. Check of KDPF or muffler function • Check the KDPF or the muffler for unusual noise comparing to the noise when they are new. If any unusual noise is heard, repair KDPF or muffler, referring to "Troubleshooting" and "Disassembly and assembly".

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Standard tightening torque table

(ALL-M140-03B-P-01-A)

(Rev. 2012/10) Table of tightening torque for bolts and nuts Unless otherwise specified, tighten the metric bolts and nuts to the torque shown in the table below.

Thread diameter (mm) 6 8 10 12 14 16 18 20 22 24 27 30 33 36 39

Width across flats (mm) 10 (*2) 10 13 (*2) 12 17 (*1, *2) 14 19 (*1, *2) 17 22 24 (*1) 22 27 30 32 36 41 46 50 55 60

Tightening torque (Nm {kgm}) 11.8 to 14.7 {1.2 to 1.5} 27 to 34 {2.8 to 3.5} 59 to 74 {6.0 to 7.5} 98 to 123 {10.0 to 12.5} 157 to 196 {16 to 20} 245 to 309 {25 to 31.5} 343 to 427 {35 to 43.5} 490 to 608 {50 to 62} 662 to 829 {67.5 to 84.5} 824 to 1,030 {84 to 105} 1,180 to 1,470 {120 to 150} 1,520 to 1,910 {155 to 195} 1,960 to 2,450 {200 to 250} 2,450 to 3,040 {250 to 310} 2,890 to 3,630 {295 to 370}

*1: Split flange bolt. *2: Flanged bolt.

00-40

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a Tighten the following flanged bolt on which "7" is stamped on its top to the tightening torque shown in the following table.

Thread diameter (mm) 6 8 10 12

Width across flats (mm) 10 12 14 17

Tightening torque (Nm {kgm}) 5.9 to 9.8 {0.6 to 1.0} 13.7 to 23.5 {1.4 to 2.4} 34.3 to 46.1 {3.5 to 4.7} 74.5 to 90.2 {7.6 to 9.2}

Unless otherwise specified, tighten the unified coarse threaded bolts and nuts to the torque shown in the table below.

Type of bolt Nominal No. threads per inch, type of thread 1/4-20UNC 5/16-18UNC 3/8-16UNC 7/16-14UNC 1/2-13UNC 9/16-12UNC 5/8-11UNC 3/4-10UNC 7/8-9UNC 1-8UNC 1 1/8-7UNC 1 1/4-7UNC 1 1/2-6UNC

125E-6 SERIES

A Tightening torque (Nm {kgm})

B Tightening torque (Nm {kgm})

Range

Target

Range

Target

9.8 to 14.7 {1 to 1.5} 24.5 to 34.3 {2.5 to 3.5} 44.1 to 58.8 {4.5 to 6} 73.5 to 98.1 {7.5 to 10} 108 to 147 {11 to 15} 157 to 216 {16 to 22} 226 to 294 {23 to 30} 392 to 530 {40 to 54} 637 to 853 {65 to 87} 883 to 1,196 {90 to 122} 1,187 to 1,608 {121 to 164} 1,598 to 2,157 {163 to 220} 2,354 to 3,177 {240 to 324}

12.7 {1.3} 29.4 {3} 52.0 {5.3} 86.3 {8.8} 127 {13} 186 {19} 265 {27} 461 {47} 745 {76} 1,040 {106} 1,393 {142} 1,873 {191} 2,765 {282}

2.9 to 3.9 {0.3 to 0.4} 6.9 to 8.8 {0.7 to 0.9} 9.8 to 14.7 {1 to 1.5} 19.6 to 24.5 {2 to 2.5} 29.4 to 39.2 {3 to 4} 44.1 to 58.8 {4.5 to 6} 63.7 to 83.4 {6.5 to 8.5} 108 to 147 {11 to 15} 177 to 235 {18 to 24} 245 to 333 {25 to 34} 333 to 451 {34 to 46} 451 to 608 {46 to 62} 657 to 892 {67 to 91}

3.43 {0.35} 7.8 {0.8} 11.8 {1.2} 21.6 {2.2} 34.3 {3.5} 51.0 {5.2} 68.6 {7} 127 {13} 206 {21} 284 {29} 392 {40} 530 {54} 775 {79}

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Unless otherwise specified, tighten the unified fine threaded bolts and nuts to the torque shown in the table below.

Type of bolt Nominal No. threads per inch, type of thread 1/4-28UNF 5/16-24UNF 3/8-24UNF 7/16-20UNF 1/2-20UNF 9/16-18UNF 5/8-18UNF 3/4-16UNF 7/8-14UNF 1-14UNF 1 1/8-12UNF 1 1/4-12UNF 1 1/2-12UNF

A Tightening torque (Nm {kgm})

B Tightening torque (Nm {kgm})

Range

Target

Range

Target

14.7 to 19.6 {1.5 to 2} 34.3 to 39.2 {3.5 to 4} 53.9 to 68.6 {5.5 to 7} 83.4 to 108 {8.5 to 11} 127 to 167 {13 to 17} 186 to 245 {19 to 25} 255 to 343 {26 to 35} 441 to 598 {45 to 61} 716 to 961 {73 to 98} 1,020 to 1,373 {104 to 140} 1,353 to 1,844 {138 to 188} 1,804 to 2,432 {184 to 248} 2,707 to 3,658 {276 to 373}

17.7 {1.8} 37.3 {3.8} 61.8 {6.3} 96.1 {9.8} 147 {15} 216 {22} 294 {30} 520 {53} 843 {86} 1,196 {122} 1,598 {163} 2,118 {216} 3,177 {324}

3.9 to 4.9 {0.4 to 0.5} 7.8 to 9.8 {0.8 to 1} 14.7 to 19.6 {1.5 to 2} 24.5 to 29.4 {2.5 to 3} 34.3 to 49.0 {3.5 to 5} 49.0 to 68.6 {5 to 7} 73.5 to 98.1 {7.5 to 10} 127 to 167 {13 to 17} 196 to 265 {20 to 27} 284 to 382 {29 to 39} 382 to 520 {39 to 53} 510 to 686 {52 to 70} 765 to 1,030 {78 to 105}

4.41 {0.45} 8.8 {0.9} 16.7 {1.7} 26.5 {2.7} 41.2 {4.2} 58.6 {6} 83.4 {8.5} 147 {15} 226 {23} 333 {34} 451 {46} 598 {61} 892 {91}

Table of tightening torque for O-ring boss piping joints a Unless otherwise specified, tighten the pipe joint for O-ring boss to the torque shown in the table below.

Nominal No. 02 — 03, 04 05, 06

00-42

Thread diameter (mm) 14 18 20 24

Width across flats (mm)

Range

Target

Varies depending on type of connector.

35 to 63 {3.5 to 6.5} 59 to 98 {6.0 to 10.0} 84 to 132 {8.5 to 13.5} 128 to 186 {13.0 to 19.0}

44 {4.5} 78 {8.0} 103 {10.5} 157 {16.0}

Tightening torque (Nm {kgm})

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Nominal No. 10, 12 14

Thread diameter (mm) 33 42

Width across flats (mm)

Tightening torque (Nm {kgm}) Range

Target

363 to 480 {37.0 to 49.0} 746 to 1,010 {76.0 to 103}

422 {43.0} 883 {90.0}

Table of tightening torque for O-ring boss plugs a Unless otherwise specified, tighten the plug for O-ring boss to the torque shown in the table below.

Nominal No. 08 10 12 14 16 18 20 24 30 33 36 42 52

Thread diameter (mm) 8 10 12 14 16 18 20 24 30 33 36 42 52

Width across flats (mm) 14 17 19 22 24 27 30 32 32 — 36 — —

Tightening torque (Nm {kgm}) Range

Target

5.88 to 8.82 {0.6 to 0.9} 9.8 to 12.74 {1.0 to 1.3} 14.7 to 19.6 {1.5 to 2.0} 19.6 to 24.5 {2.0 to 2.5} 24.5 to 34.3 {2.5 to 3.5} 34.3 to 44.1 {3.5 to 4.5} 44.1 to 53.9 {4.5 to 5.5} 58.8 to 78.4 {6.0 to 8.0} 93.1 to 122.5 {9.5 to 12.5} 107.8 to 147.0 {11.0 to 15.0} 127.4 to 176.4 {13.0 to 18.0} 181.3 to 240.1 {18.5 to 24.5} 274.4 to 367.5 {28.0 to 37.5}

7.35 {0.75} 11.27 {1.15} 17.64 {1.8} 22.54 {2.3} 29.4 {3.0} 39.2 {4.0} 49.0 {5.0} 68.6 {7.0} 107.8 {11.0} 127.4 {13.0} 151.9 {15.5} 210.7 {21.5} 323.4 {33.0}

Table of tightening torque for hose (taper seal type and face seal type) a Unless otherwise specified, tighten the hose fittings (taper seal type and face seal type) to the torque shown in the table below. a The table is applied to the threads coated with engine oil (wet threads)

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Nominal No. of hose

Width across flats (mm)

03 04 05 06 (10) (12) (14)

22 24 27 32 36 41 46 55

Tightening torque (Nm {kgm})

Taper seal

Range

Target

34 to 54 {3.5 to 5.5} 34 to 63 {3.5 to 6.5} 54 to 93 {5.5 to 9.5} 59 to 98 {6.0 to 10.0} 84 to 132 {8.5 to 13.5} 128 to 186 {13.0 to 19.0} 177 to 245 {18.0 to 25.0} 177 to 245 {18.0 to 25.0} 197 to 294 {20.0 to 30.0} 246 to 343 {25.0 to 35.0}

44 {4.5} 44 {4.5} 74 {7.5} 78 {8.0} 103 {10.5} 157 {16.0} 216 {22.0} 216 {22.0} 245 {25.0} 294 {30.0}

Face seal Nominal No. - Thread root diameter Thread size threads per (mm) inch, type of (mm) (reference) thread 9/16-18UN — 14.3 — — 14 11/16-16UN — 17.5 — — 18 13 /16-16UN 20.6 22 24 1 -14UNS 25.4 30 1 3/16-12UN 30.2 — — 33 — — 36 — — 42

Table of tightening torque for face seal joints a The tightening torque table below applies to the seal joint (sleeve nut type) a The table is applied to the threads coated with engine oil (wet threads).

Width Outside diameter of across flats (mm) pipe (mm) 8 10 12 15 {16} 22 {20}

19 22 24 {27} 30 {32} 36

Tightening torque (Nm {kgm}) Range

Target

14 to 16 {1.4 to 1.6} 24 to 27 {2.4 to 2.7} 43 to 47 {4.4 to 4.8} 60 to 68 {6.1 to 6.8} 90 to 95 {9.2 to 9.7}

15 {1.5} 25.5 {2.6} 45 {4.6} 64 {6.5} 92.5 {9.4}

Face seal Nominal No. Thread root threads per inch, diameter (mm) type of thread (reference) 9/16-18UN 14.3 11/16-16UN 17.5 13/16-16UN 20.6 1 -14UNS 25.4 30.2 1 3/16-12UN

Reference: The face seal joint of the dimension in ( ) is also used, depending on the specification. Tightening torque table for bolts and nuts on 102,107 and 114 series engines a Unless otherwise specified, tighten the metric threads bolts and nuts used on the 102, 107 and 114 series engines to the torques shown in the table below. Thread diameter (mm) 6 8 10 12 14

00-44

Tightening torque (Nm {kgm}) 10 ± 2 {1.02 ± 0.20} 24 ± 4 {2.45 ± 0.41} 43 ± 6 {4.38 ± 0.61} 77 ± 12 {7.85 ± 1.22} —

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Tightening torque table for 102, 107, and 114 series engines (joint bolts) a Unless otherwise specified, tighten the metric joint bolts used on the 102, 107, and 114 series engines to the torque shown in the table below.

Thread diameter (mm) 6 8 10 12 14

Tightening torque (Nm {kgm}) 8 ± 2 {0.81 ± 0.20} 10 ± 2 {1.02 ± 0.20} 12 ± 2 {1.22 ± 0.20} 24 ± 4 {2.45 ± 0.41} 36 ± 5 {3.67 ± 0.51}

Tightening torque table for tapered screws on 102,107, and 114 series engines (National taper pipe thread (NPT)) a Unless otherwise specified, tighten the National taper pipe threaded (NPT) screws used on the 102, 107, and 114 series engines to the torques shown in the table below. Material of female screw Nominal thread size 1/16 1/ 8 1/ 4 3/ 8 1/ 2 3/ 4

125E-6 SERIES

In cast iron or steel Tightening torque (Nm {kgm}) 15 ± 2 {1.53 ± 0.20} 20 ± 2 {2.04 ± 0.20 25 ± 3 {2.55 ± 0.31} 35 ± 4 {3.57 ± 0.41} 55 ± 6 {5.61 ± 0.61} 75 ± 8 {7.65 ± 0.82}

In aluminum Tightening torque (Nm {kgm}) 5 ± 1 {0.51 ± 0.10} 15 ± 2 {1.53 ± 0.20} 20 ± 2 {2.04 ± 0.20} 25 ± 3 {2.55 ± 0.31} 35 ± 4 {3.57 ± 0.41} 45 ± 5 {4.59 ± 0.51}

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List of abbreviation

(ALL-0360-005-A-00-A)

(Rev. 2015/01) • This list of abbreviations includes the abbreviations used in the text of the shop manual for parts, components, and functions whose meaning is not immediately clear. The spelling is given in full with an outline of the meaning. • Abbreviations that are used in general society may not be included. • Special abbreviations which appear infrequently are noted in the text (marked with a). • This list of abbreviations consists of 2 parts. The first part is a list of the abbreviations used in the text of the manual, and the second part is a list of the abbreviations used in the circuit diagrams. List of abbreviations used in the shop manual Abbreviation

ABS

AISS

AJSS

ARAC

ARSC

ASR ATT BCV CAN CDR

CLSS

CRI

ECM

00-46

Actual word spelled out

Purpose of use (major applicable machine (*), or equipment/device)

Explanation

With this function, when the tires skid (wheels stop rotating), the brakes are released, and when the wheels start to rotate, the brakes are applied again. Automatic Idling This function automatically sets the idle Engine Setting System speed. A lever is used to perform the steering Steering operations instead of a steering wheel. Advanced Joystick Steering System Moreover, it shifts gear and changes direction (WA) (FORWARD or REVERSE). When the accelerator pedal is released while Travel and brake the machine is traveling downhill, this function Automatic Retarder automatically applies the retarder with a Accelerator Control (HD, HM) constant braking force. When the accelerator pedal is released while the machine is traveling downhill, this function Travel and brake Automatic Retarder automatically applies the retarder to ensure Speed Control (HD, HM) that the machine speed does not accelerate above the speed set by the operator. When the tires spin on soft ground surfaces, Travel and brake Automatic Spin this function automatically uses the optimum Regulator (HD, HM) braking force to drive both wheels. A device that can be fixed onto a machine in Work equipment Attachment order to enable it to do different jobs. When the retarder is not being used, this Brake Brake cooling oil valve bypasses part of the brake cooling oil to control valve (HD) reduce the load on the hydraulic pump. Controller Area Communication and One of communication standards that is used Network electronic control in the network on the machine. A regulator valve which is installed to KCCV Crankcase Depression Engine ventilator. It is written as CDR valve and it is Regulator not used independently. This system can simultaneously actuate multiple actuators regardless of the load Closed-center Load Hydraulic system (provides better combined operation than O.L. Sensing System S.S.). Engine controller electronically controls supply pump, common rail, and injector. This Common Rail Injection Engine function maintains optimum fuel injection amount and fuel injection timing. Electronic control device uses the signals from the sensors on the machine. This signal Electronic Control Electronic control system indicates the optimum actuation to the Module actuators. (Same as E.C.U.) Anti-skid Brake System

Travel and brake (HD, HM)

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Abbreviation ECMV

ECSS

ECU

EGR

EMMS EPC

FOPS

F-N-R GNSS GPS

HSS

Actual word spelled out

Purpose of use (major applicable machine (*), or equipment/device)

Explanation

Proportional electromagnetic valve that gradually increases oil pressure to engage clutch and reduces transmission shock. This system ensures smooth high-speed Electronically Travel travel by absorbing vibration of machine Controlled Suspension during travel with hydraulic spring effect of (WA) System accumulator. Electronic control device uses the signals from the sensors on the machine. This signal Electronic Control Unit Electronic control system indicates the optimum actuation to the actuators. (Same as E.C.M.) This function recirculates part of exhaust gas Exhaust Gas to combustion chamber in order to reduce Engine Recirculation combustion temperature, controls emission of NOx. This system allows data (filter, oil replacement Equipment interval, malfunctions on machine, failure Management Machine monitor code, and failure history) from each sensor on Monitoring System the machine to be checked on the monitor. Electromagnetic This mechanism allows actuators to be Hydraulic system Proportional Control operated in proportion to the current supplied. This structure protects the operator's head from falling objects. (Falling Object Protective Falling Object Structure) Cab and canopy Protective Structure This performance is standardized as ISO 3449. Forward-NeutralOperation Forward-Neutral-Reverse Reverse Global Navigation A general term for positioning system using Communication Satellite System satellites such as GPS, GALILEO, etc. Communication Global Positioning This system uses satellites to determine the (KOMTRAX, KOMTRAX current location on the earth. System Plus) This function uses a combination of hydraulic motor and bevel shaft to control difference in Steering Hydrostatic Steering travel speed of right and left tracks. System (D) Accordingly machine can turn without using Electronic Control Modulation Valve

Transmission (D, HD, WA, etc.)

HST

Hydro Static Transmission

Transmission (D, WA)

ICT

Information and Communication Technology

Intelligent Machine Control

IMA

Inlet Metering Actuator Engine

IMU

Inertial Measurement Unit

Intelligent Machine Control

IMV

Inlet Metering Valve

Engine

KCCV

Komatsu Closed Engine Crankcase Ventilation

125E-6 SERIES

steering clutch. This function uses a combination of hydraulic pump and hydraulic motor to shift the speed range steplessly without using gears. A general term for the engineering and its socially applied technology of information processing and communication. This valve is installed at inlet port of pump, and it adjusts fuel intake amount in order to control fuel discharge of supply pump. Same as I.M.V. This is a device to detect the angular velocity and acceleration of the 3 axes that control motions. This valve is installed at inlet port of pump, and it adjusts fuel intake amount in order to control fuel discharge of supply pump. Same as I.M.V. (I.M.A.) This mechanism separates oil in blowby gas and returns it to the intake side to afterburn it there. It primarily consists of filters.

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Abbreviation

Actual word spelled out

Purpose of use (major applicable machine (*), or equipment/device)

KCSF

Komatsu Catalyzed Soot Filter

Engine

KDOC

Komatsu Diesel Oxidation Catalyst

Engine

KDPF

Komatsu Diesel Particulate Filter

Engine

KTCS

Komatsu Traction Control System

Travel and brake (HM system)

VGT

Komatsu Variable Geometry Turbocharger

Engine

LCD

Liquid Crystal Display

Machine monitor

LED

Light Emitting Diode

Electronic parts

LIN

Local Interconnect Network

Communication and electronic control

Load Sensing

Hydraulic system

LVDS

Low Voltage Differential Signaling

Communication and electronic control

MAF

Mass Air Flow

Engine

MMS

Multimedia Messaging Communication Service

Normally Closed

Electric and hydraulic systems

Normally Open

Electric and hydraulic systems

OLSS

Open-center Load Sensing System

Hydraulic system

Pressure Compensation

Hydraulic system

PCCS

Palm command control Steering system (D)

PCV

Pre-stroke Control Valve

00-48

Engine

Explanation This filter captures soot in exhaust gas. It is built in to KDPF. The catalyst used for purifying exhaust gas. This is built in KDPF or assembled with the muffler. This component is used to purify the exhaust gas. KDOC (catalyst) and KCSF (filter to capture soot) are built-in it. It is installed in place of the conventional muffler. This function recovers the drive force of the wheels by braking automatically with the optimum force and at the same time activates the inter-axle differential lock when the wheels idle while the machine travels on the soft ground road. The turbocharger on which the cross-section area of the exhaust passage is made variable. Image display equipment such as a monitor which assembles in the liquid crystal element. It refers to semiconductor element that emits light when the voltage is applied in forward direction. One of communication standards that is used in the network on the machine Function that detects differential pressure of pump and controls discharge amount corresponding to load. One of communication standards that is used in the network on the machine This indicates engine intake air flow.It is not used independently but it is used as combined with sensor.Mass air flow sensor can be called as MAF sensor. Service that allows transmission and reception of short messages consisting of characters or voice or images between cell phones. Device actuated to open electric or hydraulic circuits that are normally closed if not actuated. Device actuated to close electric or hydraulic circuits that are normally open if not actuated. Hydraulic system that can operate multiple actuators at the same time, regardless of the load. A function used to correct oil pressure. System in which a controller instantly analyses data from each lever, pedal, and dial, and performs optimum electronic control of the engine and transmission. This valve is installed at inlet port of pump and it adjusts fuel intake amount in order to control fuel discharge amount of supply pump.

125E-6 SERIES

00 Index and foreword Foreword, safety and general information

Abbreviation PPC PPM PTO PTP

ROPS

Actual word spelled out

Purpose of use (major applicable machine (*), or equipment/device)

Proportional Pressure Hydraulic system Control Piston Pump and Motor Power Take Off Power Tilt and power Pitch dozer

Hydraulic system (D, PC, etc.) Power transmission Work equipment (D)

Roll-Over Protective Structure

Cab and canopy

Le Systeme International d’ Unites Unit (International unit system)

SOL

Solenoid

Electric system

TWV

2-Way Valve

Hydraulic and electric systems

Explanation Used for controlling proportional pressure. This system moves actuators in proportion to the oil pressure. Piston pump and motor. Power take-off mechanism This function performs hydraulic control of the tilt and pitch of the bulldozer blade. If a machine tips over, this structure protects the operator with the seat belt fastened from being crushed. (Operator Protective Structure When Tipping) This performance is standardized as ISO 3471. Abbreviation for the "International System of Units". It is the universal unit system and "a single unit for a single quantity" is the basic principle applied. It refers to an actuator consisting of a solenoid and an iron core that is moved by the magnetic force when the solenoid is energized. Solenoid valve that switches over direction of flow.

*1: Code for applicable machine family D: Bulldozer HD: Dump truck HM: Articulated dump truck PC: Hydraulic excavator WA: Wheel loader List of abbreviations used in the circuit diagrams Abbreviation A/C A/D A/M ACC ADD AUX BR CW CCW ECU ECM ENG EXGND F.G. GND IMA NC S/T STRG 125E-6 SERIES

Actual word spelled out Air Conditioner Analogue-to-Digital Air Mix Damper Accessory Additional Auxiliary Battery Relay Clockwise Counter Clockwise Electronic Control Unit Electronic Control Module Engine External Ground Frame Ground Ground Inlet Metering Actuator No Connection Steering

00-49

00 Index and foreword Foreword, safety and general information

Abbreviation SIG SOL STD OPT OP PRESS SPEC SW TEMP T/C T/M

00-50

Actual word spelled out Signal Solenoid Standard Option Pressure Specification Switch Temperature Torque Converter Transmission

125E-6 SERIES

00 Index and foreword Foreword, safety and general information

Conversion table

(ALL-2150-931-A-00-A)

(Rev. 2012/10) Method of using the conversion table • The unit conversion table enables the simple conversion in the figures between the different units. For further details of the method of use of the conversion table, see the examples given below. Example: Method of using the conversion table to convert a unit from millimeters to inches Conversion of 55 mm into inches 1. Locate the number 50 in the vertical column at the left side, take this as (A), and then draw a horizontal line from (A). 2. Locate the number 5 in the row across the top, take this as (B), then draw a vertical line down from (B). 3. Take the point where the 2 lines cross as (C). This point (C) gives the value when converting the unit from millimeters to inches. Therefore, 55 mm = 2.165 in. Conversion of 550 mm into inches 1. The number 550 does not appear in the table, so divide it by 10 (move the decimal point one place to the left) to get 55 mm. 2. Then convert 55 mm to 2.165 in by the same procedure as above. 3. The original value (550 mm) was divided by 10, so multiply 2.165 inches by 10 (move the decimal point one place to the right) to get the original value. This gives 550 mm = 21.65 in. Therefore, 550 mm = 21.65 in. Millimeters to inches (B)

(A)

0 10 20 30 40

0 0 0.394 0.787 1.181 1.575

1 0.039 0.433 0.827 1.220 1.614

2 0.079 0.472 0.866 1.260 1.654

3 0.118 0.512 0.906 1.299 1.693

4 0.157 0.551 0.945 1.339 1.732

50 60 70 80 90

1.969 2.362 2.756 3.150 3.543

2.008 2.402 2.795 3.189 3.583

2.017 2.441 2.835 3.228 3.622

2.087 2.480 2.847 3.268 3.661

2.126 2.520 2.913 3.307 3.701

125E-6 SERIES

5 0.197 0.591 0.984 1.378 1.772 (C) 2.165 2.559 2.953 3.346 3.740

6 0.236 0.630 1.024 1.417 1.811

1 mm = 0.03937 in 7 8 9 0.276 0.315 0.354 0.669 0.709 0.748 1.063 1.102 1.142 1.457 1.496 1.536 1.850 1.890 1.929

2.205 2.598 2.992 3.386 3.780

2.244 2.638 3.032 3.425 3.819

2.283 2.677 3.071 3.465 3.858

2.323 2.717 3.110 3.504 3.898

00-51

00 Index and foreword Foreword, safety and general information

Millimeters to inches

0 10 20 30 40 50 60 70 80 90

0 0 0.394 0.787 1.181 1.575 1.969 2.362 2.756 3.150 3.543

2 0.079 0.472 0.866 1.260 1.654 2.047 2.441 2.835 3.228 3.622

3 0.118 0.512 0.906 1.299 1.693 2.087 2.480 2.847 3.268 3.661

4 0.157 0.551 0.945 1.339 1.732 2.126 2.520 2.913 3.307 3.701

5 0.197 0.591 0.984 1.378 1.772 2.165 2.559 2.953 3.346 3.740

6 0.236 0.630 1.024 1.417 1.811 2.205 2.598 2.992 3.386 3.780

7 0.276 0.669 1.063 1.457 1.850 2.244 2.638 3.032 3.425 3.819

1 mm = 0.03937 in 8 9 0.315 0.354 0.709 0.748 1.102 1.142 1.496 1.536 1.890 1.929 2.283 2.323 2.677 2.717 3.071 3.110 3.465 3.504 3.858 3.898

1 2.20 24.25 46.30 68.34 90.39 112.44 134.48 156.53 178.57 200.62

2 4.41 26.46 48.50 70.55 92.59 114.64 136.69 158.73 180.78 202.83

3 6.61 28.66 50.71 72.75 94.80 116.85 138.89 160.94 182.98 205.03

4 8.82 30.86 51.91 74.96 97.00 119.05 141.10 163.14 185.19 207.24

5 11.02 33.07 55.12 77.16 99.21 121.25 143.30 165.35 187.39 209.44

6 13.23 35.27 57.32 79.37 101.41 123.46 145.51 167.55 189.60 211.64

7 15.43 37.48 59.53 81.57 103.62 125.66 147.71 169.76 191.80 213.85

1 kg = 2.2046 lb 8 9 17.64 19.84 39.68 41.89 61.73 63.93 83.78 85.98 105.82 108.03 127.87 130.07 149.91 152.12 171.96 174.17 194.01 196.21 216.05 218.26

1 0.264 2.906 5.548 8.189 10.831 13.473 16.115 18.756 21.398 24.040

2 0.528 3.170 5.812 8.454 11.095 13.737 16.379 19.020 21.662 24.304

3 0.793 3.434 6.076 8.718 11.359 14.001 16.643 19.285 21.926 24.568

4 1.057 3.698 6.340 8.982 11.624 14.265 16.907 19.549 22.190 24.832

5 1.321 3.963 6.604 9.246 11.888 14.529 17.171 19.813 22.455 25.096

6 1.585 4.227 6.869 9.510 12.152 14.795 17.435 20.077 22.719 25.361

1 l = 0.2642 U.S.Gal 7 8 9 1.849 2.113 2.378 4.491 4.755 5.019 7.133 7.397 7.661 9.774 10.039 10.303 12.416 12.680 12.944 15.058 15.322 15.586 17.700 17.964 18.228 20.341 20.605 20.870 22.983 23.247 23.511 25.625 25.889 26.153

1 0.039 0.433 0.827 1.220 1.614 2.008 2.402 2.795 3.189 3.583

Kilograms to pounds

0 10 20 30 40 50 60 70 80 90

0 0 22.05 44.09 66.14 88.18 110.23 132.28 154.32 176.37 198.42

l to U.S. Gallons

0 10 20 30 40 50 60 70 80 90

00-52

0 0 2.642 5.283 7.925 10.567 13.209 15.850 18.492 21.134 23.775

125E-6 SERIES

00 Index and foreword Foreword, safety and general information

l to U.K. Gallons

0 10 20 30 40 50 60 70 80 90

0 0 2.200 4.399 6.599 8.799 10.998 13.198 15.398 17.598 19.797

1 0.220 2.420 4.619 6.819 9.019 11.281 13.418 15.618 17.818 20.017

2 0.440 2.640 4.839 7.039 9.239 11.438 13.638 15.838 18.037 20.237

3 0.660 2.860 5.059 7.259 9.459 11.658 13.858 16.058 18.257 20.457

4 0.880 3.080 5.279 7.479 9.679 11.878 14.078 16.278 18.477 20.677

5 1.100 3.300 5.499 7.699 9.899 12.098 14.298 16.498 18.697 20.897

6 1.320 3.520 5.719 7.919 10.119 12.318 14.518 16.718 18.917 21.117

1 l = 0.21997 U.K.Gal 7 8 9 1.540 1.760 1.980 3.740 3.950 4.179 5.939 6.159 6.379 8.139 8.359 8.579 10.339 10.559 10.778 12.528 12.758 12.978 14.738 14.958 15.178 16.938 17.158 17.378 19.137 19.357 19.577 21.337 21.557 21.777

1 7.2 79.6 151.9 224.2 296.6 368.9 441.2 513.5 585.9 658.2 730.5 802.9 875.2 947.5 1,020 1,092 1,165 1,237 1,309 1,382

2 14.5 86.8 159.1 231.5 303.8 376.1 448.5 520.8 593.1 665.4 737.8 810.1 882.4 954.8 1,027 1,099 1,172 1,244 1,316 1,389

3 21.7 94.0 166.4 238.7 311.0 383.4 455.7 528.0 600.3 672.7 745.0 817.3 889.7 962.0 1,034 1,107 1,179 1,251 1,324 1,396

4 28.9 101.3 173.6 245.9 318.3 390.6 462.9 535.2 607.6 679.9 752.2 824.6 896.9 969.2 1,042 1,114 1,186 1,259 1,331 1,403

5 36.2 108.5 180.8 253.2 325.5 397.8 470.2 542.5 614.8 687.1 759.5 831.8 904.1 976.5 1,049 1,121 1,193 1,266 1,338 1,410

6 43.4 115.7 188.1 260.4 332.7 405.1 477.4 549.7 622.0 694.4 766.7 839.0 911.4 983.7 1,056 1,128 1,201 1,273 1,345 1,418

7 50.6 123.0 195.3 267.6 340.0 412.3 484.6 556.9 629.3 701.6 773.9 846.3 918.6 990.9 1,063 1,136 1,208 1,280 1,353 1,425

kgm to ft.lb

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

0 0 72.3 144.7 217.0 289.3 361.7 434.0 506.3 578.6 651.0 723.3 795.6 868.0 940.3 1,013 1,085 1,157 1,130 1,302 1,374

125E-6 SERIES

1 kgm = 7.233 ft.lb 8 9 57.9 65.1 130.2 137.4 202.5 209.8 274.9 282.1 347.2 354.4 419.5 426.8 491.8 499.1 564.2 571.4 636.5 643.7 708.8 716.1 781.2 788.4 853.5 860.7 925.8 933.1 1,005 998.2 1,071 1,078 1,143 1,150 1,215 1,222 1,288 1,295 1,360 1,367 1,432 1,439

00-53

00 Index and foreword Foreword, safety and general information

kg/cm2 to lb/in22

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240

00-54

0 0 142.2 284.5 426.7 568.9 711.2 853.4 995.6 1,138 1,280 1,422 1,565 1,707 1,849 1,991 2,134 2,276 2,418 2,560 2,702 2,845 2,987 3,129 3,271 3,414

1 14.2 156.5 298.7 440.9 583.2 725.4 867.6 1,010 1,152 1,294 1,437 1,579 1,721 1,863 2,005 2,148 2,290 2,432 2,574 2,717 2,859 3,001 3,143 3,286 3,428

2 28.4 170.7 312.9 455.1 597.4 739.6 881.8 1,024 1,166 1,309 1,451 1,593 1,735 1,877 2,020 2,162 2,304 2,446 2,589 2,731 2,873 3,015 3,158 3,300 3,442

3 42.7 184.9 327.1 469.4 611.6 753.8 896.1 1,038 1,181 1,323 1,465 1,607 1,749 1,892 2,034 2,176 2,318 2,460 2,603 2,745 2,887 3,030 3,172 3,314 3,456

4 56.9 199.1 341.4 483.6 625.8 768.1 910.3 1,053 1,195 1,337 1,479 1,621 1,764 1,906 2,048 2,190 2,333 2,475 2,617 2,759 2,901 3,044 3,186 3,328 3,470

5 71.1 213.4 355.6 497.8 640.1 782.3 924.5 1,067 1,209 1,351 1,493 1,636 1,778 1,920 2,062 2,205 2,347 2,489 2,631 2,773 2,916 3,058 3,200 3,343 3,485

6 85.3 227.6 369.8 512.0 654.3 796.5 938.7 1,081 1,223 1,365 1,508 1,650 1,792 1,934 2,077 2,219 2,361 2,503 2,646 2,788 2,930 3,072 3,214 3,357 3,499

1 kg/cm2 = 14.2233 lb/in22 7 8 9 99.6 113.8 128.0 241.8 256.0 270.2 384.0 398.3 412.5 526.3 540.5 554.7 668.5 682.7 696.9 810.7 825.0 839.2 953.0 967.2 981.4 1,095 1,109 1,124 1,237 1,252 1,266 1,380 1,394 1,408 1,522 1,536 1,550 1,664 1,678 1,693 1,806 1,821 1,835 1,949 1,963 1,977 2,091 2,105 2,119 2,233 2,247 2,262 2,375 2,389 2,404 2,518 2,532 2,546 2,660 2,674 2,688 2,802 2,816 2,830 2,944 2,958 2,973 3,086 3,101 3,115 3,229 3,243 3,257 3,371 3,385 3,399 3,513 3,527 3,542

125E-6 SERIES

00 Index and foreword Foreword, safety and general information

Temperature Conversion of Fahrenheit to Celsius • A simple way to convert a Fahrenheit temperature reading into a Celsius temperature reading or vice versa is to see the number in the center column of the following table. The figures on the following table show the temperatures in both Fahrenheit and Celsius. • When converting from Fahrenheit to Celsius degrees, consider the center column to be a table of Fahrenheit temperatures and read the corresponding Celsius temperature in the column at the left. • When converting from Celsius to Fahrenheit degrees, consider the center column to be a table of Celsius values, and read the corresponding Fahrenheit temperature on the right. °C -40.4 -37.2 -34.4 -31.7 -28.9 -28.3 -27.8 -27.2 -26.7 -26.1 -25.6 -25.0 -24.4 -23.9 -23.3 -22.8 -22.2 -21.7 -21.1 -20.6 -20.0 -19.4 -18.9 -18.3 -17.8 -17.2 -16.7 -16.1 -15.6 -15.0 -14.4 -13.9 -13.3 -12.8 -12.2

-40 -35 -30 -25 -20 -19 -18 -17 -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10

125E-6 SERIES

°F -40.0 -31.0 -22.0 -13.0 -4.0 -2.2 -0.4 1.4 3.2 5.0 6.8 8.6 10.4 12.2 14.0 15.8 17.6 19.4 21.2 23.0 24.8 26.6 28.4 30.2 32.0 33.8 35.6 37.4 39.2 41.0 42.8 44.6 46.4 48.2 50.0

°C -11.7 -11.1 -10.6 -10.0 -9.4 -8.9 -8.3 -7.8 -7.2 -6.7 -6.1 -5.6 -5.0 -4.4 -3.9 -3.3 -2.8 -2.2 -1.7 -1.1 -0.6 0 0.6 1.1 1.7 2.2 2.8 3.3 3.9 4.4 5.0 5.6 6.1 6.7 7.2

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

°F 51.8 53.6 55.4 57.2 59.0 60.8 62.6 64.4 66.2 68.0 69.8 71.6 73.4 75.2 77.0 78.8 80.6 82.4 84.2 86.0 87.8 89.6 91.4 93.2 95.0 96.8 98.6 100.4 102.2 104.0 105.8 107.6 109.4 111.2 113.0

°C 7.8 8.3 8.9 9.4 10.0 10.6 11.1 11.7 12.2 12.8 13.3 13.9 14.4 15.0 15.6 16.1 16.7 17.2 17.8 18.3 18.9 19.4 20.0 20.6 21.1 21.7 22.2 22.8 23.3 23.9 24.4 25.0 25.6 26.1 26.7

46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80

°F 114.8 116.6 118.4 120.2 122.0 123.8 125.6 127.4 129.2 131.0 132.8 134.6 136.4 138.2 140.0 141.8 143.6 145.4 147.2 149.0 150.8 152.6 154.4 156.2 158.0 159.8 161.6 163.4 165.2 167.0 168.8 170.6 172.4 174.2 176.0

°C 27.2 27.8 28.3 28.9 29.4 30.0 30.6 31.1 31.7 32.2 32.8 33.3 33.9 34.4 35.0 35.6 36.1 36.7 37.2 37.8 40.6 43.3 46.1 48.9 51.7 54.4 57.2 60.0 62.7 65.6 68.3 71.1 73.9 76.7 79.4

1°C = 33.8°F °F 81 177.8 82 179.6 83 181.4 84 183.2 85 185.0 86 186.8 87 188.6 88 190.4 89 192.2 90 194.0 91 195.8 92 197.6 93 199.4 94 201.2 95 203.0 96 204.8 97 206.6 98 208.4 99 210.2 100 212.0 105 221.0 110 230.0 115 239.0 120 248.0 125 257.0 130 266.0 135 275.0 140 284.0 145 293.0 150 302.0 155 311.0 160 320.0 165 329.0 170 338.0 175 347.0

00-55

00 Index and foreword Foreword, safety and general information

00-56

125E-6 SERIES

SHOP MANUAL

ENGINE 125E-6 SERIES Model

Serial Number

125E-6 SERIES

01 Specification 2 01 Specification

125E-6 SERIES

01-1

01 Specification Table of contents

Table of contents (ALL-0310-002-A-00-A) 01 Specification................................................................................................................................. 01-1 Table of contents ........................................................................................................................ 01-2 Specifications............................................................................................................................. 01-3 Exhaust gas regulation ......................................................................................................... 01-3 Applicable machines ............................................................................................................ 01-6 Specifications ...................................................................................................................... 01-7 General view ..................................................................................................................... 01-10 Weight table ...................................................................................................................... 01-24 Engine performance curve .................................................................................................. 01-25

01-2

125E-6 SERIES

01 Specification Exhaust gas regulation

Specifications (ALL-2111-001-A-00-A) Exhaust gas regulation

(ENG125-A000-017-K-00-A)

• The three main diesel engine emissions that adversely impact the human body and the environment are the following: 1. NOx (nitrogen oxides): causes breathing problems and acid rain 2. HC (hydrocarbons): causes photochemical smog 3. PM (particulates in air such as soot): causes cancer and breathing problems • NOx are produced when the nitrogen (N2) in air reacts with oxygen (O2) at high temperatures. These substances are produced when a diesel engine combustion takes place with too much air (nitrogen). To reduce NOx, it is necessary to lower the combustion temperature in the cylinder to suppress the oxidation of N (nitrogen). Therefore, an air-cooled aftercooler (2) exhaust gas recirculation (EGR) is used for lowering the temperature of the air from turbocharger (1). • HC is the main component of fuel. HC in the blowby gas holds the most part of hazardous materials emitted from a diesel engine, however, this has been released into the air. • Like HC, PM is generated from imperfect combustion of fuel. It is a particle (solid substance) adhered to soot and the like. Generally speaking, reduction of NOx and reduction of PM are in paradoxical relationship, namely trying to reduce one results in increasing the other. In order to reduce PM despite this difficulty, we have employed common rail (3) so that the electronically controlled high-pressure fuel injection system can atomize the fuel sprayed, cut the injection time and optimize injection timing. • Emission regulations are established in Japan, US, and various regions in Europe. The history of the USA regulations from the 1st (Tier 1) to 4th (Tier 4) is traced in the following table. (Transition of USA EPA(*1) emission regulations, for engine rated horsepower 130 kW to 560 kW) The horizontal axis shows the NOx + NMHC(*2) level, and the vertical axis shows the PM level. In the 4th (Tier 4) regulation, both the NOx + NMHC and PM standards are tightened to levels approx.1/7 of the 3rd (Tier 3) regulation. This 4th regulation is referred to as "Tier 4 regulation" (* 3). *1: United States Environmental Protection Agency *2: General term for hydrocarbons (HC) that have a high photochemical reactivity. *3: There are two stages in Tier 4. The 1st stage is referred to as "Tier 4 Interim", for which actions are taken this time. The 2nd stage is referred to as "Tier 4 Final". 125E-6 SERIES

01-3

01 Specification Exhaust gas regulation

Actions taken to meet the Tier 4 regulation

(ENG125-A000-018-K-00-A)

1. Engine 2. Air cleaner 3. Air cooled aftercooler 4. EGR cooler dP: KDPF differencial pressure and outlet pressure sensor DOSER: Fuel doser ECU(CM2250): Engine controller EGRSOL: EPC valve (for EGR)

01-4

125E-6 SERIES

01 Specification Exhaust gas regulation

EGRV: EGR valve MAF: Mass air flow and temperature sensor PAMB: Ambient pressure sensor PCCV: Crankcase pressure sensor PIM: Charge pressure sensor REV: KVGT speed sensor SEGR: EGR valve lift sensor SVGT: KVGT position sensor T: KDPF inside temperature sensor TIM: Charge temperature sensor VGTSOL: EPC valve (for KVGT) • The following describes our major improvements done in Tier 4 over Tier 3. 1. Efficiency of EGR (Exhaust Gas Recirculation) cooler (4) has been increased (NOx reduced). 2. Intake air flow at low engine speeds is increased by utilizing variable speed operation of the turbocharger (KVGT) (PM reduced). 3. Employment of the high-precision EGR valve Oxygen density control is optimized for each driving condition by using a high precision EGR valve (EGRV), mass air flow (MAF) and temperature sensor, engine controller, and by monitoring each part of the EGR circuit (NOx and PM reduced). 4. Common rail pressure is raised to increase fuel injection pressure and microparticulate the fuel spray (PM reduced). 5. Blowby gas reduction system (KCCV) is introduced to perform internal circulation of blowby gas (HC reduced). 6. Soot collecting filter (KCSF) is introduced (PM reduced). 7. Variations between injectors are averaged by engine controller (CM2250). 8. Combustion chamber is improved (NOx and PM reduced) 9. Fuel injection and KVGT are automatically controlled by recognition of high altitude with ambient pressure sensor (PAMB) (NOx and PM reduced at a high altitude). 10.KVGT speed (REV) is monitored (to protect the KVGT). 11.When clogging of the soot collecting filter (KCSF) is detected by the differential pressure (dP) across the KDPF, the engine controller performs automatic regeneration(*), or prompts the operator to perform manual stationary regeneration on the machine monitor (to maintain the KDPF function). *: A new feature to clean (oxidize) the soot accumulated in the soot collecting filter (KCSF) inside the KDPF.

125E-6 SERIES

01-5

01 Specification Applicable machines

Applicable machines Engine SAA6D125E-6

01-6

(ENG125-A000-00V-K-00-A)

Engine serial No. PC490LC-10 HM300-3 WA470-7

Machine model Hydraulic excavator Articulated dump truck Wheel loader

125E-6 SERIES

01 Specification Specifications

Specifications

(ENG107-2110-001-A-00-A)

<Applicable machine> PC490LC-10

(ENG125-2110-030-A-00-A)

Engine name Number of cylinders – bore x stroke Total displacement Firing order

Dimension

Performance

Overall length Overall width Overall height (excluding exhaust pipe) Overall height (including exhaust pipe) Rated horsepower Max. torque Max. speed with no load (High idle speed) Min. speed with no load (Low idle speed) Fuel consumption ratio at rated point

Dry weight Fuel injection system Fuel injection system control Quantity of lubricating oil (Refill capacity) Quantity of coolant Alternator Starting motor Turbocharger

125E-6 SERIES

SAA6D125E-6 mm

6 – 125 x 150

l{cc} – mm mm

11.0 {11,040} 1–5–3–6–2–4 1,722 1,169

–

1,776

kW {HP}/rpm 270 ± 8.1 {362 ± 10.9}/1,900 Nm {kgm}/rpm 1,510 ± 45 {154 ± 4.6}/1,400 rpm

1,930 ± 25

rpm

1,000 ± 25

g/kWh {g/HP} 214.8 {160} kg – – l l – – –

1,504 High-pressure common rail type Electronic control type 46 (37) (22) 24 V, 50 A, 60 A 24 V, 7.5 kW, 11 kW Komatsu KTR85V

01-7

01 Specification Specifications

<Applicable machine> HM300-3

(ENG125-2110-030-A-02-A)

Engine name Number of cylinders – bore x stroke Total displacement Firing order

Dimension

Performance

Dry weight Fuel injection system Fuel injection system control Quantity of lubricating oil (Refill capacity) Quantity of coolant Alternator Starting motor Turbocharger

01-8

SAA6D125E-6 mm

6 – 125 x 150

l{cc} – mm mm

11.0 {11,040} 1–5–3–6–2–4 1,407 975

–

1,281

kW {HP}/rpm 248 ± 7.4 {333 ± 9.9}/2,000 Nm {kgm}/rpm 1,677 ± 50 {171 ± 5.1}/1,400 rpm

2,220 ± 50

rpm

725 (+50/0)

g/kWh {g/HPh} 208 {153} kg – – l l – – –

1,289 High-pressure common rail type Electronic control type 47 (38) (22) 24 V, 60 A, 90 A 24 V, 7.5 kW, 11 kW Komatsu KTR85V

125E-6 SERIES

01 Specification Specifications

<Applicable machine> WA470-7

(ENG125-2110-030-A-04-A)

Engine model No. of cylinders - bore x stroke Piston displacement Firing order

Dimension

Performance

Dry weight Fuel injection system Fuel injection system control Lubricating oil amount (refill capacity) Coolant amount Alternator Starting motor Turbocharger

125E-6 SERIES

SAA6D125E-6 mm

6 - 125×150

l {cc} ― mm mm

11.0 {11,040} 1―5―3―6―2―4 1,376 1,015

1,629

―

kW {HP}/rpm 204 ± 6.1 {273.6 ± 8.2}/2,000 Nm {kgm}/rpm 1,307 ± 39 {133.2 ± 4.0}/1,450 rpm

2,170 ± 50

rpm

800 (+50 / 0)

g/kWh {g/HPh} 224 {167} kg ― ― l l ― ― ―

1,486 High-pressure common rail type Electronic control system 47 (38) 22 24 V、50 A 24 V、7.5 kW Komatsu KTR85V

01-9

01 Specification General view

General view

(ENG107-2180-001-A-00-A)

<Applicable machine> PC490LC-10

(ENG125-2180-041-A-00-A)

Left side a The shape is subject to machine models.

1. Center of crankshaft 2. Rear face of flywheel housing

01-10

125E-6 SERIES

01 Specification General view

Right side a The shape is subject to machine models.

1. Center of crankshaft 2. Rear face of flywheel housing

125E-6 SERIES

01-11

01 Specification General view

Front side a The shape is subject to machine models.

1. Center of crankshaft 2. Cylinder center

01-12

125E-6 SERIES

01 Specification General view

Back side a The shape is subject to machine models.

1. Center of crankshaft 2. Cylinder center

125E-6 SERIES

01-13

01 Specification General view

<Applicable machine> HM300-3

(ENG125-2180-041-A-02-A)

Left side a The shape is subject to machine models.

1. Center of crankshaft 2. Rear face of flywheel housing

01-14

125E-6 SERIES

01 Specification General view

Right side a The shape is subject to machine models.

1. Center of crankshaft 2. Rear face of flywheel housing

125E-6 SERIES

01-15

01 Specification General view

Front side a The shape is subject to machine models.

1. Center of crankshaft 2. Cylinder center

01-16

125E-6 SERIES

01 Specification General view

Back side a The shape is subject to machine models.

1. Center of crankshaft 2. Cylinder center

125E-6 SERIES

01-17

01 Specification General view

<Applicable machine> WA470-7

(ENG125-2180-041-A-03-A)

Left side a The shape is subject to machine models.

1. Center of crankshaft 2. Rear side of flywheel housing

01-18

125E-6 SERIES

01 Specification General view

Right side a The shape is subject to machine models.

1. Center of crankshaft 2. Rear side of flywheel housing

125E-6 SERIES

01-19

01 Specification General view

Front side a The shape is subject to machine models.

1. Center of crankshaft 2. Center of cylinder

01-20

125E-6 SERIES

01 Specification General view

Back side a The shape is subject to machine models.

1. Center of crankshaft 2. Center of cylinder

125E-6 SERIES

01-21

01 Specification General view

Top a The shape is subject to machine models.

1. Center of crankshaft 2. Center of cylinder

01-22

125E-6 SERIES

01 Specification General view

Dimensions table

(ENG125-2110-2A4-A-00-A)

a These dimensions are given for reference when the engine is set on a test bench. Unit: mm Engine SAA6D125E-6

125E-6 SERIES

Machine model PC490LC-10 HM300-3 WA470-7

A 1,722 1,407 1,376

Dimension of each part B C 1,776 441 1,281 403 1,629 390

D 1,169 975 1,015

01-23

01 Specification Weight table

Weight table

(ENG125-2120-931-A-00-A)

No. Item 1 Turbocharger (KVGT) 2 Cylinder head assembly 3 Cylinder block assembly 4 Front cover

Component part Komatsu VGT Cylinder head, valve, and valve spring Cylinder block, bearing, and cap ―

Oil pan

―

Flywheel assembly

Flywheel and ring gear

Flywheel housing assembly

―

8 9

Crankshaft assembly Camshaft assembly Piston and connecting rod assembly Oil pump Supply pump Water pump

Crankshaft and crank gear Camshaft, cam gear, and thrust plate Piston, piston ring, piston pin, and connecting rod ― ― ― 24 V, 50 A 24 V, 60 A 24 V, 7.5 kW 24 V, 11 kW ― ― ― ― ―

10 11 12 13

14 Alternator 15 Starting motor 16 17 18 19 20

Boost pump EGR valve EGR cooler KDPF KCCV ventilator

01-24

Unit: kg SAA6D125E-6 27 15 305 30 PC490LC-10 18 HM300-3 22 WA470-7 22 PC490LC-10 49 HM300-3 23 WA470-7 27 PC490LC-10 68 HM300-3 47 WA470-7 47 103 16 8 5 13 10 11 11 16 18 5 11 11 72 3

125E-6 SERIES

01 Specification Engine performance curve

Engine performance curve Engine SAA6D125E-6

125E-6 SERIES

(ENG125-2170-00V-A-00-A)

Engine serial No.

Machine model PC490LC-10 HM300–3 WA470–7

Reference document page 01-26 01-27 01-28

01-25

01 Specification Engine performance curve

Engine performance curve (ENG107-2170-001-A-01-A) <Applicable machine> PC490LC-10 (ENG125-2170-34E-A-00-A) Rated horsepower: 270 ± 8.1 kW {362 ± 10.9 HP}/1,900 rpm (Gross) Max.torque: 1,510 ± 45 Nm {154 ± 4.6 kgm}/1,400 rpm (Gross)

01-26

125E-6 SERIES

01 Specification Engine performance curve

<Applicable machine> HM300-3

(ENG125-2170-34E-A-02-A)

Rated horsepower: 248± 7.4 kW {333 ± 9.9 HP}/2,000 rpm (Gross) Max.torque: 1,677 ± 50 Nm {171 ± 5.1 kgm}/1,400 rpm (Gross)

125E-6 SERIES

01-27

01 Specification Engine performance curve

<Applicable machine> WA470-7

(ENG125-2170-34E-A-03-A)

Rated horsepower: 204 ± 6.1 kW {273.6 ± 8.2 HP}/2,000 rpm (GROSS) Maximum torque: 1,307 ± 39 Nm {133.2 ± 4.0 kgm}/1,450 rpm (GROSS)

01-28

125E-6 SERIES

SHOP MANUAL

ENGINE 125E-6 SERIES Model

Serial Number

125E-6 SERIES

10 Structure and function 3 10 Structure and function

125E-6 SERIES

10-1

10 Structure and function Table of contents

Table of contents (ALL-0310-002-A-00-A) 10 Structure and function ................................................................................................................... 10-1 Table of contents ........................................................................................................................ 10-2 Components layout..................................................................................................................... 10-3 Components layout drawing.................................................................................................. 10-3 Intake and exhaust system parts .................................................................................................. 10-6 Intake and exhaust system layout drawing ............................................................................. 10-6 Intake and exhaust system circuit diagram ............................................................................. 10-7 Air cleaner ........................................................................................................................... 10-9 KVGT................................................................................................................................ 10-10 Aftercooler......................................................................................................................... 10-16 EGR system piping drawing ................................................................................................ 10-17 EGR system circuit diagram ................................................................................................ 10-19 EGR valve......................................................................................................................... 10-20 EGR cooler........................................................................................................................ 10-22 Mixing connector................................................................................................................ 10-24 KCCV layout drawing ......................................................................................................... 10-25 KCCV ventilator ................................................................................................................. 10-27 KDPF................................................................................................................................ 10-31 Engine main body parts............................................................................................................. 10-35 Cylinder head .................................................................................................................... 10-35 Cylinder block .................................................................................................................... 10-37 Main moving parts.............................................................................................................. 10-39 Vibration damper................................................................................................................ 10-42 Timing gear ....................................................................................................................... 10-43 Front cover ........................................................................................................................ 10-45 Valve system ..................................................................................................................... 10-46 Flywheel and flywheel housing ............................................................................................ 10-49 Lubrication system.................................................................................................................... 10-50 Lubrication system parts layout drawing ............................................................................... 10-50 Lubrication system diagram ................................................................................................ 10-51 Oil pump ........................................................................................................................... 10-52 Boost oil pump ................................................................................................................... 10-53 Oil filter.............................................................................................................................. 10-54 Oil cooler........................................................................................................................... 10-55 Oil cooler thermo-valve....................................................................................................... 10-56 Oil pan .............................................................................................................................. 10-57 Fuel system ............................................................................................................................. 10-58 Fuel system parts layout drawing......................................................................................... 10-58 Fuel system circuit diagram................................................................................................. 10-60 Outline of CRI system......................................................................................................... 10-63 Fuel dozing........................................................................................................................ 10-76 Fuel cooler ........................................................................................................................ 10-79 Pre-filter ............................................................................................................................ 10-80 Main filter .......................................................................................................................... 10-81 Cooling system......................................................................................................................... 10-82 Cooling system parts layout drawing.................................................................................... 10-82 Cooling system circuit diagram............................................................................................ 10-83 Water pump....................................................................................................................... 10-84 Thermostat ........................................................................................................................ 10-85 Electrical equipment.................................................................................................................. 10-87 Alternator .......................................................................................................................... 10-87 Alternator mounting ............................................................................................................ 10-91 Starting motor .................................................................................................................... 10-92 Fuel feed pump.................................................................................................................. 10-96 Fuel feed pump switch........................................................................................................ 10-97 Engine wiring harness ........................................................................................................ 10-98 Engine controller .............................................................................................................. 10-100 Sensor ............................................................................................................................ 10-106

10-2

125E-6 SERIES

10 Structure and function Components layout drawing

Components layout (ALL-A000-001-K-04-A) Components layout drawing

(ENG125-A000-04D-K-00-A)

a The shape is subject to machine models.

1. Cylinder block 2. Cylinder liner 3. Piston 4. Connecting rod 5. Piston pin 6. Crosshead 7. Intake valve 8. Exhaust valve 9. Rocker arm shaft 10. Injector 11. Cylinder head cover 12. Camshaft 13. Ring gear 14. Flywheel 15. Rear oil seal 16. Flywheel housing 125E-6 SERIES

10-3

10 Structure and function Components layout drawing

17. Oil pan 18. Crankshaft 19. Main bearing cap 20. Oil strainer 21. Crankshaft gear 22. Front cover 23. Front oil seal 24. Crankshaft pulley 25. Vibration damper

26. Exhaust manifold 27. Turbocharger 28. Cylinder head 29. Rocker arm 30. Push rod

10-4

125E-6 SERIES

10 Structure and function Components layout drawing

31. Intake manifold 32. Common rail 33. Supply pump 34. Cam follower 35. Connecting rod cap Engine Name: SAA6D125E-6 (with turbocharger and air cooled aftercooler) Type: In-line 6-cylinder, water-cooled, direct injection type, 4-cycle diesel engine

125E-6 SERIES

10-5

10 Structure and function Intake and exhaust system layout drawing

Intake and exhaust system parts (ENG107-A900-001-K-00-A) Intake and exhaust system layout drawing

(ENG125-A900-04D-K-00-A)

a The shape is subject to machine models.

1. KVGT 2. EGR valve 3. Intake connector 4. Exhaust manifold 5. EGR cooler 6. Mixing connector A: To KDPF B: From aftercooler C: To intake manifold D: From air cleaner E: To aftercooler

10-6

125E-6 SERIES

10 Structure and function Intake and exhaust system circuit diagram

Intake and exhaust system circuit diagram

(ENG125-A900-052-K-00-A)

A: From atmosphere B: To atmosphere 1. Air cleaner 2. KVGT 3. Air cooled aftercooler 4. Intake air heater 5. Intake manifold 6. Exhaust manifold 7. EGR valve 8. KCCV ventilator 9. KDPF 10. EGR cooler 11. Flywheel housing 12. Engine oil pan 13. Engine 14. Mixing connector

Function

(ENG125-A900-042-K-00-A)

• A variable displacement turbocharger KVGT (KOMATSU Variable Geometry Turbocharger), EGR system (EGR valve and EGR cooler) which sends a part of exhaust gas back to the combustion chamber in order to suppress generation of NOx, KDPF (KOMATSU Diesel Particulate Filter) which purifies the exhaust gas, and a blowby gas recirculation system KCCV (KOMATSU Closed Crankcase Ventilation) are introduced for this engine. • Clean air is necessary to maintain the engine performance. If dirt or dust enters, the engine can get damaged and the performance may be degraded. • Air flows through air cleaner (1), KVGT (2), and air cooled aftercooler (3) into the engine. 125E-6 SERIES

10-7

10 Structure and function Intake and exhaust system circuit diagram

• The KVGT has a variable geometry mechanism not found in conventional turbochargers. The KVGT can get seriously damaged if foreign material enters the KVGT. Therefore, a high quality air cleaner is essential for the engine. Follow the procedures in the Operation and Maintenance Manual to clean or replace the air cleaner element, and be careful not to let foreign material enter the system during replacement work. • Intake air flows from air cleaner (1) into the compressor side of KVGT (2). The air charged at KVGT (2) is cooled at air cooled aftercooler (3). The air then flows through mixing connector (14), air intake manifold (5) and then into the cylinders for combustion. • Exhaust gas is sent from exhaust manifold (6) to the turbine side of KVGT (2). Thus the turbine wheel is driven by the energy of the exhaust gas. • The engine controller outputs signals to the EGR system for opening EGR valve (7) most properly according to the load on the engine to attain both clean exhaust gas and low fuel consumption. • When EGR valve (7) opens, part of the exhaust gas (EGR gas) flows from exhaust manifold (6) through EGR piping to EGR cooler. • The exhaust gas cooled by EGR cooler (10) flows through EGR valve (7) and mixes with the intake air in mixing connector (14), then flows into intake manifold (5). • KDPF (9) is installed to meet the new exhaust gas regulations. The KDPF consists of KDOC (oxidation catalyzer) and KCSF (soot collecting filter). • Particulate soot in the exhaust gas are collected to purify the exhaust gas.

10-8

125E-6 SERIES

10 Structure and function Air cleaner

Air cleaner

(ENG125-A910-041-K-00-A)

a The shape is subject to machine models.

1. Vacuator valve 2. Inlet 3. Air cleaner clogging sensor or dust indicator mounting 4. Outlet 5. Mass air flow and temperature sensor mounting part 6. Rectifying wire mesh 7. Outer element 8. Inner element

Specifications

(ENG125-A910-030-K-00-A)

• Type: Cyclopac type • Filtering area (outer element): 14.7 m2 • Filtering area (inner element): 1.85 m2

Operation

(ENG125-A910-044-K-00-A)

• Since inlet (2) is placed tangentially, the intake air is sucked in while swirling along the body and a centrifugal force is generated by the swirl flow. • The dust contained in the intake air is separated by the centrifugal separation effect. • More than 99.9% of the dust is removed by outer element (7) and only clean air is sucked into the engine through outer element (7), rectifier wire net (6), and outlet (4). • Rectifier wire net (6) rectifies the air flow to the mass air flow sensor (5) which is important to the engine control. • The dust separated while the air is sucked in is discharged out automatically through evacuator valve (1) when the engine is stopped.

125E-6 SERIES

10-9

10 Structure and function KVGT

KVGT

(ENG125-AA10-041-K-00-A)

KVGT: Abbreviation for KOMATSU Variable Geometry Turbocharger and denotes the variable displacement turbocharger. a The shape is subject to machine models.

10-10

125E-6 SERIES

10 Structure and function KVGT

1. Blower housing 2. KVGT speed sensor 3. Hydraulic actuator 4. Turbine housing 5. Plate 6. Vane 7. Nozzle ring 8. Push rod 9. Shaft 10. Blower impeller 11. Turbine impeller 12. Piston A: Air intake inlet B: Air intake outlet C: Exhaust inlet D: Exhaust outlet

Operation

(ENG125-AA10-044-K-00-A)

1. Air cleaner 2. KVGT 3. KDPF 4. EGR cooler 5. EGR valve C: Blower impeller T: Turbine impeller • The new exhaust gas regulation not only requires to control emissions at high engine speed but also at low engine speed. To meet the requirements, the EGR ratio is increased. (EGR ratio = volume of EGR/ intake air flow) • To obtain a high EGR ratio especially at low engine speed, the turbine inlet pressure (P3) must be higher than the boost pressure (P2). A variable displacement turbocharger (KVGT), in which the exhaust gas pressure hitting the turbine impeller (T) can be adjusted, is introduced. • The charged pressure rises faster, also contributing to suppress the generation of PM (particles) due to insufficient oxygen at low engine speed. • The turbine impeller (T) drives the blower impeller (C) via a shaft to send a large amount of air to the cylinders for combustion. When the air flow from KVGT (2) increases, more fuel can be injected, and the engine output increases. • Since the density of the air and the amount of oxygen increases when the air is cooled, more fuel can be injected, and the engine output increases.

125E-6 SERIES

10-11

10 Structure and function KVGT

a Adequate amount of clean high quality oil is required to maintain the KVGT performance. Be sure to use Komatsu genuine high quality oil. Follow the procedures in the Operation and Maintenance Manual when replacing oil or oil filter.

• Exhaust gas enters from (C) of turbine housing (4), and flows out from (D) through section (P). Section (P) is surrounded by plate (5) and nozzle ring (7) fixed on turbine housing (4), and vane (6). • The passage area varies when push rod (8) slides right or left. • The hydraulic actuator (3) moves piston (12) in the actuator up/down by using the oil pressure controlled at the EPC valve installed to the front cover, and also controls the right/left slide of push rod (8). • Exhaust gas flows through vanes (6) and rotates turbine impeller (11), the torque of which rotates blower impeller (10) via shaft (9). This works as a compressor and the air entered from (A) is compressed and sent out from (B). • When the exhaust gas pressure at the inlet (C) of turbine housing (4) is low (at low engine speed), push rod (8) slides to the right to narrow section (P). • Then the exhaust gas pressure to turbine impeller (11) increases, the turbocharger speed also increases, and more air (oxygen) is inhaled. • The turbocharger speed is sensed by KVGT speed sensor (2). When nozzle ring is closed • At low engine speed, exhaust gas inlet passage (P) is narrowed (L1). (Not completely closed.) • When the turbine inlet pressure increases while the nozzle ring is closed, the flow speed to the turbine increases and the turbocharger speed increases.

10-12

125E-6 SERIES

10 Structure and function KVGT

When nozzle ring is open • At high engine speed, exhaust gas inlet passage (P) is widened (L2). • As the engine speed and the turbine inlet pressure (exhaust gas pressure) increases, exhaust gas inlet passage (P) widens (L2) to effectively apply the exhaust gas pressure to turbine impeller (11).

a Nozzle ring (7), vane (6) and rod (8) are integrated and slide together but do not rotate. a KVGT position sensor is installed to hydraulic actuator (3). The KVGT position sensor is calibrated together with the variable mechanism in the KVGT, and values are stored in the memory inside the KVGT position sensor. If any of the hydraulic actuator (3), KVGT position sensor, or KVGT body fails, replace the whole KVGT. Hydraulic actuator operation • Hydraulic actuator (6) is moved by the oil pressure controlled by EPC valve (8) installed to the front cover. • The force for the movement is the oil pressure supplied from boost pump (12). a The shape is subject to machine models.

125E-6 SERIES

10-13

10 Structure and function KVGT

• Position of hydraulic actuator (6) is sensed by KVGT position sensor (5) and the signals are fed back to engine controller (7).

1. Air cleaner 2. Mass air flow and temperature sensor

10-14

125E-6 SERIES

10 Structure and function KVGT

3. KVGT 4. KVGT speed sensor 5. KVGT position sensor 6. Hydraulic actuator 7. Engine controller 8. EPC valve (for KVGT) 9. KDPF 10. EGR system (EGR cooler and EGR valve) 11. EGR valve lift sensor C. Blower impeller T. Turbine impeller KVGT control system • Based on information from KVGT position sensor (5), mass air flow and temperature sensor (2), and KVGT speed sensor (4), etc., the engine controller (7) moves hydraulic actuator (6) by using the oil pressure controlled by EPC valve (8), and then move the piston. • A good response at high altitudes is maintained by sensing high elevations with the ambient pressure sensor, and automatically controlling the fuel injection and the KVGT. • The KVGT is protected by controlling its speed to prevent overspeed. Lubrication • Cooled oil from the engine oil cooler is sent through the supply pipe to the KVGT for lubrication • Oil is sent to the bearing housing to lubricate the shaft bearing and thrust bearing. • Return oil is drained from the return pipe connected to the bottom of the bearing housing and falls to the oil pan. Cooling • Coolant from the cylinder block enters the center housing to cool the KVGT. • Returning coolant flows from the center housing to the radiator.

125E-6 SERIES

10-15

10 Structure and function Aftercooler

Aftercooler

(ENG125-A9A0-041-K-00-A)

a The shape is subject to machine models.

1. Core 2. Tank 3. Tube 4. Fin A: Intake air outlet B: Intake air inlet

Specifications • • • •

(ENG125-A9A0-030-K-00-A)

Cooling method: Core type: Triangle slate Fin pitch: 4.0/2 Total heat dissipation area: 29.98 m2

10-16

125E-6 SERIES

10 Structure and function EGR system piping drawing

EGR system piping drawing

(ENG125-A9J0-04D-K-00-A)

EGR: Abbreviation for Exhaust Gas Recirculation a The shape is subject to machine models.

1. KVGT 2. EGR valve 3. Air intake connector 4. Intake manifold 5. Exhaust manifold 6. EGR cooler 7. Mixing connector

Function

(ENG107-A9J0-042-K-00-A)

• EGR valve (driven hydraulically) Controls the gas flow from the exhaust system to the air intake system. Since the exhaust pressure is higher than the boost pressure, the exhaust gas flows to the air intake side. 125E-6 SERIES

10-17

10 Structure and function EGR system piping drawing

• EGR cooler Cools the exhaust gas. Engine coolant is used for cooling. • Air intake connector Returns the air from the air-cooled aftercooler and exhaust gas from the EGR valve to the air intake side. • Each sensor Controls the EGR according to the operating condition. Troubleshoots the system. • Controls each part of the EGR circuit and controls the EGR rate according to the operating condition to ensure clean exhaust at all times. • Since the EGR circuit is monitored and troubleshooted, a serious trouble is prevented.

10-18

125E-6 SERIES

10 Structure and function EGR system circuit diagram

EGR system circuit diagram

(ENG125-A9J0-052-K-00-A)

EGR: Abbreviation for Exhaust Gas Recirculation

1. Air cleaner 2. KDPF 3. Ambient pressure sensor 4. Aftercooler 5. EGR cooler 6. EGR valve 7. Hydraulic actuator (power piston) 8. EPC valve (for EGR valve) 9. EGR valve lift sensor 10. Exhaust manifold 11. Boost pump 12. Intake manifold 13. Charge (boost) pressure and temperature sensors 14. Engine controller 15. Mixing connector C: Blower impeller T: Turbine impeller

Operation

(ENG125-A9J0-044-K-00-A)

• The engine controller outputs signals for opening EGR valve (6) most properly according to the load on the engine to attain both clean exhaust gas and low fuel consumption. • When EGR valve (6) opens, a part of the exhaust gas (EGR gas) flows from exhaust manifold (10) through EGR piping to EGR cooler (5). • The exhaust gas cooled by EGR cooler (5) flows through EGR valve (6) and mixes with the intake air in mixing connector (15), and then flows into intake manifold (12). 125E-6 SERIES

10-19

10 Structure and function EGR valve

EGR valve

(ENG125-A9K1-041-K-00-A)

a The shape is subject to machine models.

1. Valve 2. Spring 3. Power piston 4. Spool 5. Spring 6. EGR valve lift sensor 7. EPC valve (for EGR) A: EGR gas inlet (from EGR cooler) B: EGR gas outlet (to intake manifold) C: Servo drive oil inlet D: Servo drive oil outlet Structure • The EGR valve consists of the EGR gas flow control mechanism and the EPC valve . • An EPC valve is provided for EGR valve control, and an EPC valve for KVGT control is installed to front cover.

10-20

125E-6 SERIES

10 Structure and function EGR valve

Operation

(ENG107-A9K1-044-K-00-A)

• Oil from the boost oil pump flows into the EGR valve from port (C). Control pressure from the EPC valve flows into port (E). • Spool (4) is pressed to the right by the reaction force of spring (5), and EGR valve (1) is closed by the reaction force of spring (2) Therefore, exhaust gas from the EGR cooler does not flow to the intake side. • To open EGR valve (1), first the control pressure from the EPC valve enters port (E). Spool (4) moves to a position whereat this control pressure and the force of spring (5) are balanced. • The hydraulic circuit in power piston (3) opens, and then the oil from the boost oil pump entering from port (C) pushes power piston (3) to the left. • Oil from the boost oil pump acts on power piston (3) and generates force (Fp). • When force (Fp) becomes larger than reaction force (Fs) of spring (2), EGR valve (1) opens and then exhaust gas will flow to the intake side. • Since the hydraulic circuit to spool (4) is closed by movement of power piston (3), power piston (3) stops at a position determined by spool (4). • The valve position is controlled by the engine controller by controlling the spool position with the control pressure of the EPC valve. • A servo mechanism prevents external force applied to valve (1) from acting on spool (4), which is in contact with power piston (3). • Position of spool (4) is sensed by the EGR valve lift sensor.

125E-6 SERIES

10-21

10 Structure and function EGR cooler

EGR cooler

(ENG125-A9L0-041-K-00-A)

a The shape is subject to machine models.

1. Header plate 4. Shell A: EGR gas inlet B: EGR gas outlet (to EGR valve) C: Coolant inlet D: Coolant outlet E: Air vent F: Air vent

2. Flat tube 3. Inner fin

Operation

(ENG125-A9L0-044-K-00-A)

• The EGR gas enters from (A) and flows through 9 flat tubes (2).

10-22

125E-6 SERIES

10 Structure and function EGR cooler

• Coolant enters from (C) and flows around flat tube (2) in shell (4) and then goes out from (D). • The EGR gas is effectively cooled by flat tubes (2) with inner fins (3) and flows out from EGR gas outlet (B).

125E-6 SERIES

10-23

10 Structure and function Mixing connector

Mixing connector

(ENG125-A9Q5-041-K-00-A)

A. Air inlet B. EGR gas inlet C. To cylinder head (intake gas) 1. Intake manifold 2. Mixing connector 3. Intake connector 4. Electric air heater

Function

(ENG125-A9Q5-042-K-00-A)

Mixes EGR gas with air.

10-24

125E-6 SERIES

10 Structure and function KCCV layout drawing

KCCV layout drawing

(ENG125-A180-04D-K-00-A)

KCCV: Abbreviation for KOMATSU Closed Crankcase Ventilation a The shape is subject to machine models.

1. KCCV ventilator 2. KVGT 3. Check valve 4. CDR valve A: Blowby gas B: Engine oil-free blowby gas (to KVGT) C: Engineoil that C is separated (to oilpan) • Formerly blowby gas (A) was discharged to the atmosphere as is. However, the tightened exhaust gas regulation no longer permits releasing blowby gas to the atmosphere. • Since blowby gas (A) contains engine oil components, which may cause the following problems when recirculated to KVGT (2), a filter is provided at KCCV ventilator (1) to remove the oil. 1. Degraded performance of turbocharger and aftercooler due to adherence of engine oil 2. Abnormal engine combustion 3. Malfunction of sensors due to adherence of engine oil

125E-6 SERIES

10-25

10 Structure and function KCCV layout drawing

Operation

(ENG125-A180-044-K-00-A)

a The figure on the left shows the traditional flow of blowby gas that has been discharged to the atmosphere. The figure on the right shows the flow of blowby gas recirculated to the intake system by the KCCV ventilator.

1. Air cleaner 2. KVGT 3. Aftercooler 4. Cylinder block (crankcase) 5. Breather 6. KCCV ventilator 7. Oil pan • Engine oil is removed from blowby gas (A) in cylinder block (4) by the filter in KCCV ventilator (6), and then the cleaned gas (B) is recirculated to the intake side of the KVGT. • Separated engine oil (C) flows through a check valve and falls to the oil pan.

10-26

125E-6 SERIES

10 Structure and function KCCV ventilator

KCCV ventilator

(ENG125-A18H-041-K-00-A)

a The shape is subject to machine models.

1. Case 2. CDR valve 3. Crankcase pressure sensor 4. Relief valve 5. Impactor 6. Filter 7. Heater tube A: Blowby gas inlet (engine breather) B: Blowby gas outlet (to KVGT intake side) C: Oil drain port (to oil pan) D: Coolant inlet E: Coolant outlets

Function

(ENG125-A18H-042-K-00-A)

• When blowby gas is recirculated to the intake side of the KVGT, the pressure inside the crankcase becomes negative, and dust may be sucked in through the crankshaft seals. Therefore, CDR valve (regulator valve) controls the pressure inside the crankcase. • If the filter in the KCCV ventilator clogs, pressure inside the crankcase increases and oil may leak, so clog of filter is detected by crankcase pressure sensor. • There are two types of filters that differ by the filter replacement method; the top load type (removed upward) and the bottom load type (removed downward). • Warmed engine coolant is conducted to the locations that pose potential problem of freezing to prevent it from happening.

125E-6 SERIES

10-27

10 Structure and function KCCV ventilator

Operation

(ENG107-A18H-044-K-00-A)

• Blowby gas enters (A) and large oil particles in the engine oil mist are separated when it flows through the hole of impactor (5) in filter (6). • Small oil particles are separated by filter (6). • The separated oil flows along the case wall to oil drain port (C), and then flows into the oil pan. • When the crankcase pressure becomes negative, CDR valve (2) operates to prevent the crankcase pressure from becoming excessively negative. • The crankcase pressure sensor (3) senses the blowby gas pressure (crankcase pressure). • If the engine controller judges from the value sensed by the crankcase pressure sensor (3) that the filter is clogged, it displays failure code CA555 and then displays CA556 if the pressure increases further. • Relief valve (4) is installed inside case (1) and operates to protect the KCCV ventilator and engine when filter (6) is blocked.

CDR valve

(ENG107-A18A-041-K-00-A)

CDR: Abbreviation for Crankcase Depression Regulator

1. Diaphragm 2. Spring A: Crankcase side B: VGT side (intake side) • The CDR valve is a regulator valve which prevents excessive negative crankcase pressure (P1). • Normally, diaphragm (1) is pushed up by spring (2) and blowby gas flows from crankcase side (A) to VGT side (intake side) (B). • When intake air flow at VGT side (intake side) (B) increases and crankcase pressure (P1) decreases, the reaction force of spring (2) yields to ambient pressure (P2). The diaphragm shuts the passage and temporarily blocks the flow. • Then, when blowby gas accumulates in the crankcase and pressure (P1) recovers, the diaphragm is pushed up again and blowby gas starts to flow again.

10-28

125E-6 SERIES

10 Structure and function KCCV ventilator

Forming of condensed water and emulsion

(ENG125-A18H-14H-K-00-A)

1. Air cleaner 2. KVGT 3. Aftercooler 4. Engine 5. Breather 6. KCCV ventilator 7. Oil pan Outline • If the machine is continuously operated in a low load condition at low ambient temperatures, the moisture in the blowby gas may condense instead of evaporating away. The water will flow through KCCV ventilator (6) to oil pan (7). The following occurs: 1. Moisture in the blowby gas condenses inside KCCV piping (A). 2. The condensed water flows through the drain circuit to the oil pan. 3. The water in the oil pan evaporates. 4. When the vapor condenses again at a relatively cool place inside the engine, it mixes with oil and forms a milky mixture. This mixture is so-called "mayonnaise sludge"(*). * : A mixture of oil and water, emulsified like mayonnaise (emulsion) 5. Mayonnaise sludge will deposit during low load operation when various parts in the engine are not warmed up enough. • Mayonnaise sludge is formed at low temperature areas that cause condensation, such as inside of breather (B), back side of head cover (C), and dipstick (D).

125E-6 SERIES

10-29

10 Structure and function KCCV ventilator

• Mayonnaise sludge will evaporate away as the engine is operated under load and the engine oil temperature increases. • Condensation water of the blowby gas in oil is harmless. However, if any engine coolant is in oil, the engine must be checked for coolant leakage.

10-30

125E-6 SERIES

10 Structure and function KDPF

KDPF

(ENG125-A9H0-041-K-00-A)

KDPF: Abbreviation for KOMATSU Diesel Particulate Filter a The shape is subject to machine models.

1. Inlet unit 2. KDOC inlet temperature sensor 3. KDOC outlet temperature sensor 4. KCSF unit 5. Aggregate connector box 6. KDPF outlet temperature sensor 7. Outlet unit 8. KDPF differencial pressure sensor port 9. KDPF differencial pressure sensor 10. KDPF differential pressure sensor port 11. KDOC unit 12. Hanger bracket 13. Sensor bracket 14. Sensor bracket band 15. Water drain port A: From KVGT B: Exhaust C: Water drain • The KDPF consists of the following components: inlet unit (1) to introduce exhaust gas, KDOC unit (11) that houses an oxidation catalyst, KCSF unit (4) that houses a soot collecting filter with a catalyzer, and outlet unit (7) that sends out exhaust gas and has a "dam" to prevent rain water from entering KCSF unit (4).

125E-6 SERIES

10-31

10 Structure and function KDPF

• KDOC unit (11) consists of a ceramic honeycomb coated with oxidation catalyst material. By using this ceramic honeycomb, it regenerates (*1) NO (nitrogen monoxide) to NO2 (nitrogen dioxide) in exhaust gas. • The ceramic honeycomb is guarded by a mat made of special fiber to prevent damage caused by engine and machine vibrations. • The mat also prevents overheating of the KDPF outer periphery by insulating the heat generated at the ceramic honeycomb during operation. • The KCSF unit (4) also consists of a ceramic honeycomb coated with oxidation catalyst material, like the KDOC unit (11). This ceramic honeycomb collects soot. • Three temperature sensors and one differential pressure sensor (an integrated KDPF differential pressure and KDPF outlet pressure sensor) are installed to the KDPF. • Temperature signals from these three temperature sensors are used in combination to monitor the KDOC and KCSF operations and to perform various troubleshootings. • The differential pressure sensor detects the amount of soot deposited in the KCSF by sensing the pressure difference across the KCSF. Like the temperature sensors, this sensor is also used for various troubleshootings. *1: Denotes to purification (oxidation) processing of soot. k While engine is running and for some time after engine is stopped, the surface of KDPF and

nearby piping are extremely hot. Be careful not to get burned when working near the KDPF.

Function

(ENG125-A9H0-042-K-00-A)

A: Flow of exhaust gas 1. KDOC(oxidation catalyzer) 2. KCSF 3. Sealing (made of ceramics) 4. Cell 5. Ceramics honeycomb • The KDPF purifies the exhaust gas by catching most of the granulous or chain-like soot formed by the PM (particulates in air such as soot) included in the exhaust from the engine. • KCSF (2) is made of ceramic.

10-32

125E-6 SERIES

10 Structure and function KDPF

• Inside the KCSF (2), there are many cells partitioned by ceramic walls. Cells plugged at the inlet side and cells plugged at the outlet side are alternately arranged. • The soot deposited in KCSF (2) are naturally oxidized and burned away by the effect of KDOC (1) (oxidation catalyzer), in operating conditions with relatively high exhaust gas temperatures. (This is referred to as "passive regeneration".) • On the other hand, when the exhaust temperature is relatively low, in conditions such as continued low load operations, the deposit of soot in KCSF (2) increases. • The engine controller continuously monitors the amount of deposited soot by estimating from the operating conditions and calculating based on the KCSF (2) differential pressure sensor signals. • When the soot deposit exceeds a certain level, and the engine is operated with the exhaust gas temperature exceeding a certain level, the engine controller executes "automatic regeneration" to burn (oxidize) the soot. • During automatic regeneration, the engine controller automatically controls the fuel injection timing and the KVGT to raise the exhaust temperature. (This operation is called "exhaust temperature-raising control") • As the exhaust temperature increases, the engine controller automatically performs calculations based on the exhaust temperature at the KDOC inlet and flow of the exhaust gas, so that KCSF (2) can efficiently burn (oxidize) the soot. • Fuel is injected from (fuel doser) installed to the outlet portion of turbocharger. (Fuel dosing) Fuel that is injected into this piping mixes with exhaust gas and combusts (oxidizes) soot by the action of KDOC (1). • Automatic regeneration is not performed when regeneration is executed from the machine monitor, or when the outside air temperature is extremely low, and when the exhaust gas temperature is not high enough to burn soot because the engine has been operated at low loads for a while. Thus, soot deposit in the KCSF (2) will increase. • If the soot deposit in the KCSF (2) exceeds a certain level, it will be necessary to perform "manual stationary regeneration" to burn away (oxidize) the soot in the KCSF (2). • If the soot deposit exceeds the acceptable level, the exhaust gas flow will be restricted. This can increase fuel consumption, degrade engine combustion, or cause other problems. • If the soot deposit exceeds the limit to safely perform "manual stationary regeneration", the KDPF fails and replacement becomes unavoidable. Make sure to follow the procedures in the Operation and Maintenance Manual when performing "manual stationary regeneration"

Types of soot regeneration functions

(ENG125-A9H0-042-K-01-A)

a Regeneration refers to a new function used for purifying (oxidizing) soot accumulated in the soot collection filter (KCSF) inside the KDPF. 1. Passive regeneration When the engine exhaust temperature is relatively high, the catalyst effect of the KDOC to oxidize soot will be stronger and the soot deposit in the KCSF will be naturally burned away. 2. Active regeneration (increase of engine exhaust temperature + fuel dosing) 1) Automatic regeneration This is the regeneration process started automatically when the soot deposit exceeds a certain level. At this time, the engine controller performs the exhaust temperature-raising control mode (*1) and fuel dosing (*2). Another type of automatic regeneration is performed by the engine controller at certain intervals, regardless of the amount of soot deposited in the KCSF. (= time-dependent regeneration) *1: The fuel injection timing and the KVGT are controlled to raise the exhaust temperature. *2: Fuel is injected to increase the exhaust temperature and accelerate the regeneration process. 2) Manual stationary regeneration (*3) When the exhaust temperature does not reach a certain level due to the machine operating condition, or when regeneration is disabled by the operator, automatic regeneration will not be performed and the soot deposit in the KCSF may increase. In such conditions, the machine monitor displays a manual stationary regeneration request. The operator must perform regeneration by operating the machine monitor on its screen. A regeneration feature is also provided for the technician who should use this feature from the machine monitor menu after engine controller replacement, KDPF replacement, and KCSF ash cleaning. (=Regeneration for service (*2)) • A KDPF drying feature is provided to prevent excessive accumulation of unburned fuel in the KDPF when the machine is operated for a long time with low exhaust temperature.

125E-6 SERIES

10-33

10 Structure and function KDPF

• When certain conditions are met, the engine controller automatically switches control to increase the exhaust temperature to dry the KDPF. If some of the conditions for automatic drying are not met, manual stationary regeneration may be requested. a Follow the procedures in the Operation and Maintenance Manual when starting and stopping KDPF regeneration. a Be sure to use ultra-low-sulfur diesel fuel. Non-specified fuels may cause KDPF failure. a Be sure to use the specified Komatsu genuine oil for the KDPF. Non-specified oils may cause KDPF clogging in a short time, resulting in increased fuel consumption or KDPF failure. a Do not modify the KDPF itself or exhaust pipes. Modifications disturb normal operation of the KDPF, leading to a failure. a Do not apply impacts to the KDPF by stepping on, dropping, or striking it. The KDPF contains a ceramic honeycomb, which can be damaged by strong impacts. a The engine controller performs automatic regeneration even when the amount of soot deposit is low. Since this is programmed to maintain the KDPF performance, this is normal. a During automatic regeneration and manual stationary regeneration, the KVGT automatically operates and the engine sound changes. The flow of exhaust gas through the KDPF changes and the exhaust sound changes, but this is normal. a During automatic regeneration and manual stationary regeneration, especially at low temperatures, white smoke may come out from the exhaust pipe for a short time, but this is normal. Be sure to perform regeneration at a well ventilated place since carbon monoxide can be produced. a During automatic regeneration and manual stationary regeneration, a strange odor may be smelled from the exhaust pipe, but this is normal. a During automatic regeneration and manual stationary regeneration, the exhaust temperature at the exhaust pipe can exceed 650 °C. Make sure that there is no flammable material near the exhaust system to prevent fire. Make sure that nobody is standing in front of the exhaust pipe, and pay sufficient attention to safety of the environment. a KDPF temperature values are shown below for reference. KDOC_In (KDOC inlet temperature sensor) Not regenerating (idling) Regenerating (under exhaust temperature-raising control: 1,000 rpm)

10-34

100 to 250 °C

KDOC_Out (KDOC outlet temperature sensor) 100 to 250 °C

KDPF_Out (KDPF outlet temperature sensor)

400 to 550 °C

125E-6 SERIES

10 Structure and function Cylinder head

Engine main body parts (ENG107-R402-001-K-00-A) Cylinder head

(ENG125-A100-041-K-00-A)

The shape is subject to change depending the machine model.

1. Coolant air tube 2. Cylinder head bolt 3. Injector 4. Fuel spill tube 5. Valve guide 6. Cylinder head 7. Cylinder head cover 8. Valve seat insert 9. Rocker arm housing

125E-6 SERIES

10-35

10 Structure and function Cylinder head

Specifications

(ENG125-A100-030-K-00-A)

Cylinder head • Direct fuel injection type • 4-valve • Overhead injector (Common rail system specification) • Split type 1-cylinder, 1-head Valve seat • Valve seat inserts are press fitted to both intake and exhaust valves Head cover • Float-type seal

10-36

125E-6 SERIES

10 Structure and function Cylinder block

Cylinder block

(ENG125-A300-041-K-00-A)

a The shape is subject to machine models.

1. Cylinder block 2. Cylinder liner 3. Clevis seal 4. Liner ring (Ethylene-propylene rubber) 5. Liner ring (Silicon rubber) 6. Front seal 7. Front cover 8. Main cap bolt 9. Main bearing cap 10. Main bearing 11. Thrust bearing 12. Piston cooling nozzle

125E-6 SERIES

10-37

10 Structure and function Cylinder block

Specifications

(ENG125-A300-030-K-00-A)

Cylinder block • Crankshaft: 7 bearings • Camshaft: 7 bearings Front oil seal • Single lip with dust seal Piston cooling • With piston cooling nozzle Cylinder liner • Wet type • Machining on inside: and nitrocarburizing Liner ring • Upper: Clevis seal • Middle: O-ring (Ethylene-propylene rubber) • Lower: O-ring (Silicon rubber)

10-38

125E-6 SERIES

10 Structure and function Main moving parts

Main moving parts

(ENG125-R403-001-K-00-A)

a The shape is subject to machine models.

1. Piston (FCD piston) 2. Connecting rod bushing 3. Piston pin 4. Crankshaft 5. Crank gear (33 teeth) 6. Connecting rod cap 7. Connecting rod bearing 8. Connecting rod 9. Connecting rod cap bolt 10. Top ring 11. Second ring 12. Oil ring

125E-6 SERIES

10-39

10 Structure and function Main moving parts

Specifications

(ENG125-R403-030-K-00-A)

Crankshaft • Closed die forging • Journal, fillet induction hardening Piston • Special thin ductile cast iron (FCD piston) • Re-entrant combustion chamber Connecting rod lubricating oil hole: Made Piston cooling from connecting rod end: Applied Features of FCD piston • The FCD piston has high heat resistance • The FCD piston has low thermal expansion factor and the clearance between the liner and it can be reduced. • Since the FCD piston has high strength, the top ring can be installed to a higher place, and the loss area of the combustion chamber can be reduced. • The exhaust sound is low and the exhaust gas color is better. • The output can be heightened. Piston ring

10-40

125E-6 SERIES

10 Structure and function Main moving parts

Top ring (1): Double-side keystone, inner cut, barrel face, hard chromium-plated Second ring (2): Keystone, inner cut, taper face, hard chromium-plated Oil ring (3): With coil expander and nitrided surface

125E-6 SERIES

10-41

10 Structure and function Vibration damper

Vibration damper

(ENG125-A5E0-041-K-00-A)

a The shape is subject to machine models.

1. Vibration damper 2. Dowel pin 3. Mounting bolt

Function

(ENG107-A5E0-042-K-00-A)

• The vibration damper absorbs the torsional vibration that acts on the crankshaft and prevents damage and abnormal wear of the crankshaft and gears.

10-42

125E-6 SERIES

10 Structure and function Timing gear

Timing gear

(ENG125-A5A0-041-K-00-A)

a The shape is subject to machine models.

1. Cylinder block 2. Water pump drive gear (22 teeth) 3. Main idler gear, large (57 teeth) 4. EGR oil pump drive gear (20 teeth) 5. Main idler gear, small (38 teeth) 6. Oil pump drive gear (21 teeth) 7. Oil pump idler gear (25 teeth) 8. Injection drive gear (44 teeth) 9. Front cover 10. Camshaft gear (44 teeth) 11. Crankshaft gear (33 teeth) 12. Crankshaft 125E-6 SERIES

10-43

10 Structure and function Timing gear

A.B.C: Each match mark for timing gears

10-44

125E-6 SERIES

10 Structure and function Front cover

Front cover

(ENG125-A5B2-041-K-00-A)

a The shape is subject to machine models.

1. Front cover 2. Boost pump mounting hole 3. EPC valve mounting place

125E-6 SERIES

10-45

10 Structure and function Valve system

Valve system

(ENG125-A700-041-K-00-A)

1. Rocker arm shaft 2. Cam roller 3. Cam roller pin 4. Camshaft 5. Camshaft gear (44 teeth) 6. Adjustment screw 7. Locknut 8. Crosshead 9. Valve seat (upper) 10. Intake valve 11. Valve spring 12. Valve spring seat (lower) (both IN and EX) 13. Adjustment screw 14. Locknut 15. Rocker arm 16. Push rod 17. Cam follower 18. Valve cotter 19. Exhaust valve

10-46

125E-6 SERIES

10 Structure and function Valve system

20. Valve stem seal (both IN and EX)

A: No.1 cylinder intake side B: No.1 cylinder exhaust side Camshaft: Closed die forging Journal and cam: Induction hardened

125E-6 SERIES

10-47

10 Structure and function Valve system

Specifications

(ENG125-A700-030-K-00-A)

Valve timing

10-48

125E-6 SERIES

10 Structure and function Flywheel and flywheel housing

Flywheel and flywheel housing

(ENG125-A560-041-K-00-A)

Without PTO

a The shape is subject to machine models. 1. Flywheel housing 2. Ring gear 3. Flywheel 4. Rear seal

Specifications

(ENG125-A560-030-K-00-A)

Machine model PC490LC-10 HM300-3 WA470-7

125E-6 SERIES

148

Number of internal teeth of flywheel ―

137

―

Number of teeth of ring gear

10-49

10 Structure and function Lubrication system parts layout drawing

Lubrication system (ENG107-AB00-001-K-00-A) Lubrication system parts layout drawing

(ENG125-AB00-04D-K-00-A)

a The shape is subject to machine models.

1. EGR valve 2. Engine oil pan 3. Boost pump 4. KVGT 5. Engine oil filter

10-50

125E-6 SERIES

10 Structure and function Lubrication system diagram

Lubrication system diagram

(ENG125-AB00-052-K-00-A)

1. Strainer 2. Oil pump 3. Relief valve 4. Oil cooler 5. Oil filter 6. Safety valve 7. Lubrication of KVGT 8. Lubrication of main gallery 9. Lubrication of each bearing 10. Boost pump 11. Regulator valve 12. EPC valve (for KVGT) 13. KVGT 14. EPC valve (for EGR valve) 15. EGR valve 16. Piston cooling gallery 17. Lubrication of piston 18. Oil pan

125E-6 SERIES

10-51

10 Structure and function Oil pump

Oil pump

(ENG125-AB50-041-K-00-A)

a The shape is subject to machine models. 1. Oil pump drive gear (21 teeth) 2. Bushing 3. Pump cover 4. Drive gear 5. Pump body 6. Drive shaft 7. Main relief valve 8. Valve spring 9. Retainer 10. Driven shaft 11. Bushing 12. Driven gear

Specifications

(ENG125-AB50-030-K-00-A)

Oil pump Type: Gear pump Speed: Engine speed x 1.571 Main relief valve Cracking pressure: 0.65 to 0.8 MPa {6.63 to 8.16 kg/cm2}

Function

(ENG107-AB50-042-K-00-A)

• The oil pump feeds engine oil which lubricates the inside of the engine. • The pump is installed between the oil pan and regulator valve circuit, and is driven by the camshaft.

10-52

125E-6 SERIES

10 Structure and function Boost oil pump

Boost oil pump

(ENG125-A9N0-041-K-00-A)

a The shape is subject to machine models.

1. Main relief valve a. Center of drive shaft b. Discharge port c. Suction port

Specifications

(ENG125-A9N0-030-K-00-A)

Oil pump • Type: Gear pump • Speed: Engine speed x 1.1 Main relief valve • Cracking pressure: 1.43 ± 0.1 MPa {14.6 ± 1 kg/cm2}

Function

(ENG125-A9N0-042-K-00-A)

• The boost oil pump feeds engine oil which drives the EGR valve and the KVGT. • The pump is installed between the main gallery EGR valve and KVGT circuit, and is driven by the main idler gear. • The pump feeds oil pressure to the EGR valve drive, EGR valve control, KVGT drive, and KVGT control circuits.

125E-6 SERIES

10-53

10 Structure and function Oil filter

Oil filter

(ENG125-ABC0-041-K-00-A)

Remote mount type

a The shape is subject to machine models. A: Oil inlet B: Oil outlet 1. Safety valve 2. Filter head 3. Cartridge

Specifications

(ENG125-ABC0-030-K-00-A)

Oil filter Filtration area: 0.44 m2 (Full flow) Safety valve Cracking pressure: 343 ± 19 kPa {3.5 ± 0.2 kg/cm2}

10-54

125E-6 SERIES

10 Structure and function Oil cooler

Oil cooler

(ENG125-B810-041-K-00-A)

a The shape is subject to machine models. a. Water drain b. Oil inlet c. To each part of engine (oil) d. Water inlet 1. Thermostat cover 2. Thermostat (thermo valve) 3. Cooler cover 4. Cooler element 5. Strainer

Specifications

(ENG125-B810-030-K-00-A)

Oil cooler thermostat (thermo valve) Cracking temperature: 71 °C ± 1.5 °C Full opening temperature: 85 °C Full opening lift: Min. 8 mm Oil cooler Total heat dissipation area: 0.575 m2

125E-6 SERIES

10-55

10 Structure and function Oil cooler thermo-valve

Oil cooler thermo-valve

(ENG125-B810-041-K-01-A)

1. Piston 2. Valve 3. Holder 4. Spring 5. Spring 6. Seat 7. Pellet

Specifications

(ENG125-B810-030-K-01-A)

Cracking temperature: 71 ± 1.5 °C Full opening temperature: 85 °C Full opening lift: Min. 8 mm

Function

(ENG125-B810-042-K-00-A)

This valve is installed in oil cooler. It opens when oil reaches a specified temperature to bypass oil.

10-56

125E-6 SERIES

10 Structure and function Oil pan

Oil pan

(ENG125-AB20-041-K-00-A)

a The shape is subject to machine models.

1. Oil pan 2. Dipstick 3. Oil level sensor

125E-6 SERIES

10-57

10 Structure and function Fuel system parts layout drawing

Fuel system (ENG107-AD00-001-K-00-A) Fuel system parts layout drawing

(ENG125-AD00-04D-K-00-A)

a The shape is subject to machine models.

10-58

125E-6 SERIES

10 Structure and function Fuel system parts layout drawing

1. Main filter 2. Injector 3. Supply pump 4. Common rail 5. High-pressure pipe 6. Pressure limiter valve 7. Feed pump A: From cooling plate B. To cooling plate

125E-6 SERIES

10-59

10 Structure and function Fuel system circuit diagram

Fuel system circuit diagram

(ENG125-AD00-052-K-00-A)

1. Fuel tank 2. Supply pump assembly 2A. PCV 2B. High pressure pump 2C. Priming pump 2D. Feed pump 2E. Bypass valve 2F. G speed sensor 3. Fuel filter 4. Overflow valve 5. Common rail 6. Pressure limiter 7. Flow damper 8. Injector assembly 9. Fuel cooler 10.Engine controller

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125E-6 SERIES

10 Structure and function Fuel system circuit diagram

11.NE speed sensor 12.Fuel feed pump 13.Check valve 14.Pre-fuel filter 15.Fuel doser solenoid valve assembly 15A. Fuel doser solenoid valve 1 15B. Fuel doser solenoid valve 2 15C. Dosing fuel pressure sensor 16.Fuel doser 17.Relief valve

Operation

(ENG125-AD00-044-K-00-A)

• The fuel system is of an electronically controlled high pressure common rail type. The high-pressure common rail system consists of four main components. • They are feed pump (low-pressure fuel pump) (12), supply pump (high-pressure fuel pump) (2), common rail (8) and injector (5). • The fuel system uses injectors (3) driven by solenoids. • The engine controller (EC) controls the solenoid in each injector (3) to control the fuel supply and timing to the injector (3). • By controlling the solenoids electronically, the flow and timing are precisely controlled.

2. Supply pump 5. Common rail 8. Injector EC: Engine controller PS: Common rail pressure sensor • Supply pump (2) feeds high-pressure fuel to common rail (5). High-pressure fuel is stored in common rail (5). • Engine controller (EC) controls the solenoid in each injector (8) to control the fuel supply and timing to the injector (8). • Fuel flows to fuel feed pump through pre-filter (14) with water separator. • Fuel is discharged from fuel feed pump (12), filtrated at main filter (3) and then enters supply pump (2). • Fuel in supply pump (2) is pressurized to a high pressure by two plungers. • Common rail (5) accumulates fuel and works as a fuel manifold when distributing fuel to supply line of each injector (8). • By using common rail pressure sensor (PS) in common rail (5), engine controller (EC) monitors pressure supplied from supply pump (2) to common rail (5). • The pressure detected by common rail pressure sensor (PS) is used by engine controller (EC) to regulate the fuel pressure from supply pump (2). • Pressure limiter (6) (common rail pressure relief) is installed in common rail (4). • Pressure limiter (6) is a safety valve that relieves common rail pressure if it exceeds the predetermined threshold value. • Fuel that is relieved by pressure limiter (6) returns to fuel tank (1) through fuel return circuit connected to common rail (4).

125E-6 SERIES

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10 Structure and function Fuel system circuit diagram

• High-pressure fuel flows to the side of injector (8) and is injected when solenoid is energized and internal needle is raised. • In active regeneration by KDPF, fuel doser supplies fuel to piping to increase exhaust gas temperature at KDOC.

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125E-6 SERIES

10 Structure and function Outline of CRI system

Outline of CRI system

(ENG125-AD00-04A-K-00-A)

Outline • The CRI system detects the condition of the engine (engine speed, accelerator throttle position, coolant temperature, etc.) with sensors. • The microcomputer of the CRI system controls the fuel injection rate, fuel injection timing, fuel injection pressure, etc. totally to operate the engine under the best condition. • The CRI system has a self-diagnosis function and an alarm function, with which the computer of the system checks the main component parts and notifies the operator of detected failures. • In addition, the CRI system has a fail-safe function which stops the engine when a certain parts fail and a backup function which continues the operation by changing the control method in such a case. Configuration • The CRI system is divided by the function into the fuel system and control system.

Fuel system

(ENG125-AD00-042-K-00-A)

• The fuel system distributes the high-pressure fuel supplied by the supply pump to the cylinders through the common rail. • The solenoid valve in the injector opens and closes the nozzle needle valve to start and finish injection.

125E-6 SERIES

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10 Structure and function Outline of CRI system

Various controls

(ENG125-AP00-042-K-01-A)

• The CRI system controls the fuel injection rate and fuel injection timing more properly than the mechanical governor or timer of the conventional fuel injection pump. • For the control of the system, calculations necessary to the engine controller are performed from the signals sent from the sensors installed to the engine and machine. • The energizing timing and duration of the injector are so controlled that the optimum quantity of fuel will be injected in the optimum timing.

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125E-6 SERIES

10 Structure and function Outline of CRI system

Fuel injection rate control function

(ENG125-AG12-042-K-00-A)

• The fuel injection rate control function, which replaces the function of the conventional governor, controls the fuel injection rate to an optimum one according to the signals of engine speed and accelerator throttle position.

Fuel injection timing control function

(ENG125-AG13-042-K-00-A)

• The fuel injection timing control function, which replaces the conventional timer function, controls the fuel injection timing to an optimum one according to the signals of engine speed and fuel injection rate.

Fuel injection pressure control function

(ENG125-AG14-042-K-00-A)

(Common rail fuel pressure control function) • The fuel injection control function (common rail fuel pressure control function) controls the fuel delivery rate of the supply pump by measuring the fuel pressure using the common rail fuel pressure sensor and feeding it back to the engine controller. • This function performs pressure feedback control so that the fuel injection pressure will be the same as the optimum value (command value) set according to the engine speed and fuel injection rate.

Structure and operation of CRI system

(ENG125-AD00-040-K-00-A)

• The CRI system consists of the fuel supply pump, common rail, injector, engine controller to control them, and sensors. • The fuel supply pump generates common rail fuel pressure. The fuel pressure is controlled by the fuel delivery rate of the supply pump. • The delivery rate is controlled by turning on and off the PCV (pressure control valve) of the fuel supply pump according to the electric signals from the engine controller. • The common rail receives the pressurized fuel from the fuel supply pump and distributes it to the cylinders. • The fuel pressure is sensed by the common rail fuel pressure sensor installed to the common rail. • A feedback control is applied so that the actual fuel pressure will match to the command pressure set according to the engine speed and the load on the engine. • The fuel pressure in the common rail is applied to the nozzle side of the injector and to the control chamber through the fuel injection pipe of each cylinder.

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10 Structure and function Outline of CRI system

• The injector controls the fuel injection rate and fuel injection timing by turning ON and OFF the TWV (2way solenoid valve). • When the TWV is turned ON (energized), the fuel circuit is so changed that the high-pressure fuel in the control chamber will flow through the orifice. As a result, the needle valve is raised to start fuel injection by the nozzle cracking pressure of the high-pressure fuel on the nozzle side. • When the TWV is turned OFF (de-energized), the fuel circuit is so changed that the high-pressure fuel will be applied to the control chamber through the orifice. As a result, the needle valve lowers and finishes fuel injection. • Accordingly, the fuel injection timing and fuel injection rate are controlled respectively by the timing to turn ON the TWV and the length of the turn-on time of the TWV.

Structure and operation of component parts Supply pump

(ENG125-AD00-001-K-01-A)

(ENG125-AD70-041-K-00-A)

1. 3-head cam 2. Overflow valve 3. Drive gear 4. No.1 high-pressure pump 5. PCV (pressure control valve) 6. No.2 high-pressure pump 7. Priming pump 8. Feed pump 9. Gear for Bkup speed sensor (G sensor)

Function

(ENG125-AD70-042-K-00-A)

Outline • The supply pump consists of priming pump (7), feed pump (8) and high-pressure pumps (4) and (6). • The function of the supply pump is to generate common rail fuel pressure by controlling the fuel delivery.

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10 Structure and function Outline of CRI system

Structure • High-pressure pumps (4) and (6) have the pressure feed systems similar to those of the conventional inline fuel injection pump and the PCVs (pressure control valves) for each cylinder to control the fuel delivery. • By employing the 3-head cam (1), the necessary number of the cylinders of high-pressure pumps (4) and (6) is reduced to 1/3 of the engine cylinders. • Since the frequency of feeding fuel to the common rail is the same as that of fuel injection, the common rail fuel pressure is smooth and stable. • The fuel fed by high-pressure pumps (4) and (6) to the common rail is categorized as follows. • No.1 high-pressure pump (on the drive gear side) (4) compensates for drop in the common rail fuel pressure caused by fuel injection into the No.1, 3 and 5 cylinders. • No.2 high-pressure pump (on the feed pump side) (6) compensates for drop in the common rail fuel pressure caused by fuel injection into the No.2, 4 and 6 cylinders.

Operation

(ENG125-AD70-044-K-00-A)

• (A): During the lowering stroke of the plunger, the PCV is open and the low-pressure fuel is sucked in the plunger chamber through the PCV. • (B): While the PCV is not energized and is open after the plunger starts the rising stroke, the sucked fuel is returned through the PCV without being pressurized. • (C): If the PCV is energized and closed in the timing for the necessary delivery, the return passage is closed and the pressure in the plunger chamber rises. Accordingly, the fuel is fed through the delivery valve (check valve) to the common rail. That is, the quantity of the fuel corresponding to the plunger lift after the PCV is closed is the delivery. The delivery is changed and the common rail fuel pressure is controlled by changing the opening timing (pre-stroke of plunger) of the PCV. • (D): After the cam passes the maximum lift point, the plunger starts the lowering stroke and the pressure in it decreases. At this time, the delivery valve closes to stop feeding the fuel. Since the PCV is de-energized, it opens and the low-pressure fuel is sucked in the plunger chamber, namely the state of (A) starts again. PCV (pre-stroke control valve) • The PCV adjusts the fuel delivery from the supply pump to adjust the common rail fuel pressure. The delivery from the supply pump to the common rail is decided by the timing of energizing the PCV. 125E-6 SERIES

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10 Structure and function Outline of CRI system

Feed pump • The feed pump built in the supply pump assembly sucks up the fuel from the fuel tank and sends it to the high-pressure pump chamber through the fuel filter. • The feed pump is driven by the camshaft. Its outer and inner rotors start rotating when driven. • The fuel is sucked in on the suction side and discharged on the delivery side according to the increase and decrease of the spaces between the outer and inner rotors.

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10 Structure and function Outline of CRI system

Common rail

(ENG125-AE21-041-K-00-A)

Structure • Common rail (4) distributes the high-pressure fuel generated on high-pressure pump to the injectors of the cylinders. • Common rail (4) is equipped with common rail fuel pressure sensor (2), flow damper (1) and pressure limiter (3). • The fuel injection pipes are connected to flow dampers (1) to send the high-pressure fuel to the injectors. • The piping of pressure limiter (3) is returned to the fuel tank.

Flow damper

(ENG125-AE23-042-K-00-A)

Function • The flow dampers reduce the pressure pulses in the high-pressure piping and supply the fuel to the injectors with stable pressure. • If excessive fuel flows out, the flow dampers block the fuel passage to prevent abnormal outflow of the fuel. • If the fuel flows out abnormally, high pressure is applied to the piston, which moves to the right until it reaches the seat to stop the flow of fuel. 125E-6 SERIES

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10 Structure and function Outline of CRI system

Operation

(ENG125-AE23-044-K-00-A)

When fuel is not injected • Piston (2) is in contact with stopper (1). (Initial position) • The fuel for static leakage is supplied through the clearance between orifice (a) of piston (2) and sliding portion. When fuel is injected • Piston (2) compresses spring (3) with pressure of fuel and moves to the right. • The fuel for dynamic leakage is supplied through the clearance between orifice (a) of piston (2) and sliding portion. When fuel is stopped • If the fuel flows out abnormally because of a burst of the piping, etc., piston (2) moves to the right stroke end. • The end of piston (2) touches seat (b) to stop the flow of fuel. • Once the fuel is stopped, piston (2) does not return to the initial position until the engine is stopped.

Pressure limiter • If abnormally high pressure is generated, the pressure limiter opens to release that pressure. • If the common rail fuel pressure reaches about 200 MPa {2,040 kg/cm 2} the pressure limiter operates (opens). • If the common rail fuel pressure lowers to 30 MPa {310 kg/cm 2}, the pressure limiter resets itself (closes) until the engine is topped. • Under the normal condition, the pressure limiter does not reset itself (close) until the engine is stopped.

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10 Structure and function Outline of CRI system

1. Ball 2. Housing 3. Spring 4. Body 5. Guide Common rail fuel pressure sensor • The common rail fuel pressure sensor is installed to the common rail to sense the fuel pressure. • This sensor is a semiconductor pressure sensor, which utilizes the phenomenon that the electric resistance of silicon changes according to pressure applied to it.

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10 Structure and function Outline of CRI system

Injector

(ENG125-AE60-04A-K-00-A)

Function (ENG125-AE60-042-K-00-A) • The function of the injector is to inject the high-pressure fuel from the common rail into each combustion chamber of the engine in the optimum timing, by the optimum quantity, at the optimum injection rate, and under the optimum spray condition while referencing signals from engine controller. • The TWV (2-way solenoid valve) controls the start and finish of fuel injection by controlling the pressure in the control chamber. • The orifice restricts the nozzle valve opening speed to control the fuel injection rate. • The hydraulic piston transmits the force generated by the pressure in the control chamber to the needle valve of the nozzle. • The nozzle has the function of atomizing fuel.

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10 Structure and function Outline of CRI system

Structure

(ENG125-AE60-041-K-00-A)

1. Inlet connector 2. Terminal 3. Upper body 4. Solenoid 5. Valve body 6. Orifice (OUT) 7. Orifice (IN) 8. Pressure control chamber 9. Control piston 10. Spring 11. Pressure pin 12. Nozzle assembly 13. QR code tab 125E-6 SERIES

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10 Structure and function Outline of CRI system

• The injector consists of the traditional nozzle section, orifice to control the fuel injection rate, hydraulic piston, and 2-way solenoid valve.

A: When fuel is not injected B: When fuel injection is started C: When fuel injection is finished D: From common rail 1. Nozzle 2. Control piston 3. Orifice (IN) 4. Orifice (OUT) 5. Valve body 6. Solenoid 7. Spring 8. Pressure control chamber

Operation

(ENG125-AE60-044-K-00-A)

1) When fuel is not injected (A) • When solenoid (6) is not energized, valve body (5) is pushed down by spring (7). • Since the high-pressure fuel is applied from the common rail to pressure control chamber (8), nozzle (1) is closed and the fuel is not injected. 2) When fuel injection is started (B) • When solenoid (6) is energized, valve body (5) is pulled up by the electromagnetic force and the fuel passage opens. • Since the fuel in pressure control chamber (8) flows out through orifices (3) and (4), nozzle (1) rises and fuel injection pump starts. • The fuel injection rate is gradually increased by the function of orifices (3) and (4). • If energization of solenoid (6) is continued, injection rate is set to the maximum.

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10 Structure and function Outline of CRI system

3) When fuel injection is finished (C) • When solenoid (6) is de-energized, valve body (5) is lowered by spring (7) and the fuel passage is closed. • At this time, the high-pressure fuel in the common rail is applied to pressure control chamber (8) suddenly and nozzle (1) is closed quickly, fuel injection is finished sharply.

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10 Structure and function Fuel dozing

Fuel dozing

(ENG125-A9H6-001-K-00-A)

Dozing piping drawing

(ENG125-A9H6-04D-K-00-A)

1. Fuel doser 2. Fuel doser solenoid valve 1 3. Fuel doser solenoid valve 2 4. Doser fuel pressure sensor 5. Fuel feed pump A: From pre-filter B: To fuel tank

Outline

(ENG125-A9H6-04A-K-00-A)

• In active regeneration by KDPF, the fuel doser supplies exhaust piping to increase the exhaust gas temperature at KDOC. • The fuel, which is pressurized by the electrical fuel feed pump, is fed to the fuel doser since fuel doser solenoid valve 1 opens during active regeneration. • When active regeneration is finished, fuel doser solenoid valve 1 closes, stopping fuel supply. And at the same time, the remaining pressure is discharged because the fuel doser solenoid valve 2 opens at this point.

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10 Structure and function Fuel dozing

Fuel doser

(ENG125-A9H6-042-K-00-A)

1. Fuel doser A: Fuel inlet B: Coolant inlet C: Coolant outlet • The engine controller calculates volume of the fuel to be injected by fuel doser (1) necessary to procure appropriate KDOC outlet temperature. • The engine controller drives fuel doser (1) in order to have injection of the calculated volume of fuel by controlling PWM according to the pressure detected by the doser fuel pressure sensor.

Fuel doser solenoid valve and doser fuel pressure sensor

(ENG125-A9JE-042-K-00-A)

1. Fuel doser solenoid valve 1 2. Fuel doser solenoid valve 2 3. Doser fuel pressure sensor A: Fuel inlet B: Fuel outlet (to fuel doser) 125E-6 SERIES

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10 Structure and function Fuel dozing

C: Fuel outlet (drain) • The fuel doser solenoid valves (1) and (2) are assembled with doser fuel pressure sensor (3) as fuel doser solenoid valve. • Mesh filter is installed to fuel inlet (A) of the fuel doser solenoid valve assembly. • Doser fuel pressure sensor (3) measures pressure of fuel supplied to the fuel doser. • When active regeneration is finished, fuel doser solenoid valve (1) closes, stopping fuel supply. And at the same time, the remaining pressure is drained because the fuel doser solenoid valve (2) opens at this point.

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10 Structure and function Fuel cooler

Fuel cooler

(ENG125-B7W0-041-K-00-A)

a The shape is subject to machine models. A: From fuel tank B: To supply pump 1. Mount bracket 2. Core

Specifications

(ENG125-B7W0-030-K-00-A)

Cooling method: Cooling with air Core type: AL-CFT-1 Total heat dissipation area: 3.31 m2

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10 Structure and function Pre-filter

Pre-filter

(ENG125-AEA0-041-K-00-A)

a The shape is subject to machine models. A: Fuel inlet B: Fuel outlet 1. Air bleeding plug 2. Filter head 3. Cartridge

Specifications

(ENG125-AEA0-030-K-00-A)

Filtration area: 1.0 m2

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10 Structure and function Main filter

Main filter

(ENG125-AED0-041-K-00-A)

a The shape is subject to machine models. A: Fuel inlet B: Fuel outlet 1. Air bleeding plug 2. Filter head 3. Cartridge

Specifications

(ENG125-AED0-030-K-00-A)

Filtration area: 1.0 m2

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10 Structure and function Cooling system parts layout drawing

Cooling system (ENG107-B110-001-K-00-A) Cooling system parts layout drawing

(ENG125-B110-04D-K-00-A)

a The shape is subject to machine models.

1. EGR cooler 2. KVGT 3. Water pump 4. Oil cooler A. From radiator B. To radiator

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10 Structure and function Cooling system circuit diagram

Cooling system circuit diagram

(ENG125-B110-052-K-00-A)

1. Radiator 2. Thermostat 3. Cylinder head 4. KVGT 5. EGR cooler 6. Cylinder block 7. Engine oil cooler 8. Water pump 9. Water manifold 10. Coolant temperature sensor 11. Fuel dozer 12. KCCV a: Flow when thermostat is open b: Flow when thermostat is closed

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10 Structure and function Water pump

Water pump

(ENG125-BA10-041-K-00-A)

Mounting

a The shape is subject to machine models. A: To radiator (coolant) B: From engine (coolant) C: To engine via water pump (coolant) D: From radiator (coolant) E: From oil pump (oil) F: To engine (oil) a. Water drain valve 1. Thermostat 2. Thermostat housing 3. Water pump 4. Oil cooler

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10 Structure and function Thermostat

Thermostat

(ENG125-BA30-041-K-00-A)

a The shape is subject to machine models.

1. Thermostat 2. Thermostat housing a: To radiator b: To water pump

Specifications

(ENG125-BA30-030-K-00-A)

• Cracking temperature: 76.5 ± 2 ℃ • Full opening temperature: 90 °C • Valve lift: Min. 9 mm

Operation

(ENG125-BA30-044-K-00-A)

When coolant is cool (when valve is closed) When the coolant temperature is lower than the valve opening temperature of the thermostat, valve (1) is closed. As a result, coolant (C) from cylinder block and cylinder head flows to water pump (A) without flowing to radiator.

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10 Structure and function Thermostat

When coolant is warm (when valve is open) As the coolant temperature reaches valve opening temperature, expansion action of heat sensing part (2) opens valve (1) and coolant (C) flows to radiator (B).

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10 Structure and function Alternator

Electrical equipment (ENG107-AK50-001-K-00-A) Alternator

(ENG125-AKK0-041-K-00-A)

Alternator with built-in regulator (Open type, 50A)

(ENG125-AKK0-041-K-01-A)

a The shape is subject to machine models. 1. Alternator 2. Alternator pulley 3. Terminal B 4. Terminal R 5. Terminal E 6. Internal electrical circuit diagram 6A. Initial energizing resistor 6B. Regulator 6C. Field coil

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10 Structure and function Alternator

Specifications Engine

(ENG125-AKK0-030-K-00-A)

Machine model PC490LC-10

SAA6D125E-6

10-88

WA470-7

Type Open type (brushless), manufactured by Nikko Electric Industry

Pulley SpecificaOutside Number tion diameter of stage (mm) 8 80 24 V, 50 A 75 2

Weight (kg)

125E-6 SERIES

10 Structure and function Alternator

Alternator with built-in regulator (Open type, 60A)

(ENG125-AKK0-041-K-02-A)

Specifications Engine

SAA6D125E-6

125E-6 SERIES

(ENG125-AKK0-030-K-01-A)

Machine model PC490LC-10 HM300-3

Type Open type (brushless), manufactured by Nikko Electric Industry

Pulley SpecificaOutside Number tion diameter of stage (mm) 24 V, 60 A

Weight (kg)

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Alternator with built-in regulator (Open type, 90A)

(ENG125-AKK0-041-K-03-A)

a The shape is subject to machine models. 1. Alternator 2. Alternator pulley 3. Terminal B 4. Terminal E 5. Terminal R 6. Internal electrical circuit diagram 6A. Field coil 6B. Initial energizing resistor 6C. Regulator

Specifications Engine

SAA6D125E-6

10-90

(ENG125-AKK0-030-K-02-A)

Machine model

HM300–3

Type Open type (brushless), manufactured by Nikko Electric Industry

Pulley SpecificaOutside Number tion diameter of stage (mm) 24 V, 90 A

Weight (kg)

125E-6 SERIES

10 Structure and function Alternator mounting

Alternator mounting

(ENG125-AKN0-041-K-00-A)

a The shape is subject to machine models.

1. Alternator 2. Alternator drive belt 3. Crankshaft pulley 4. Alternator bracket 5. Tensioner

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10 Structure and function Starting motor

Starting motor

(ENG-AK70-001-K-00-A)

With built-in safety relay (7.5kW)

(ENG125-AK70-041-K-00-A)

a The shape is subject to machine models. 1. Pinion gear 2. Starting motor (body) 3. Magnetic switch 4. External electrical circuit diagram [2P connector (male)] 4A. Safety relay

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10 Structure and function Starting motor

4B. Starting motor 5. Connector specifications Type A: 2P connector (male) B, C, R, S, E: Each terminal

Specifications

(ENG125-AK70-030-K-00-A)

Engine

Machine model

Type

Specification

SAA6D125E-6

PC490LC-10 HM300-3 WA470-7

Water-proof, oil-proof type, manufactured by Nikko Electric Industry

24 V, 7.5 kW

125E-6 SERIES

Number of Connector Weight (kg) pinion type teeth 12

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10 Structure and function Starting motor

With built-in safety relay (11kW)

(ENG125-AK70-041-K-01-A)

a The shape is subject to machine models. 1. Pinion gear 2. Starting motor (body) 3. Magnetic switch 4. External electrical circuit diagram 4A. Safety relay 4B. Starting motor

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10 Structure and function Starting motor

5. Connector specifications Type A: 2P connector (male) B, C, R, S, E: Each terminal

Specifications

(ENG125-AK70-030-K-01-A)

Engine

Machine model

SAA6D125E-6

PC490LC-10 HM300-3 (if equipped)

125E-6 SERIES

Type

Specification

Water-proof, oil-proof type, manufactured by 24 V,11 kW Nikko Electric Industry

Number of Connector Weight (kg) pinion type teeth 12

10-95

10 Structure and function Fuel feed pump

Fuel feed pump

(PC400-AEH0-041-K-00-A)

1. Body 2. Rubber 3. Bracket 4. Connector A. Fuel inlet B. Fuel outlet

Function

(PC400-AEH0-042-K-00-A)

Operates according to the control by the engine controller or timer of the fuel feed pump switch for the following purposes. • Increases the fuel pressure in the fuel dosing process. (Control by engine controller) • Bleed air from the fuel route (engine side). (Control by timer of fuel feed pump switch)

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10 Structure and function Fuel feed pump switch

Fuel feed pump switch

(PC400-AEH5-041-K-00-A)

1. Body 2. Toggle switch 3. LED lamp 4. Connector

Function

(PC400-AEH5-042-K-00-A)

• Receives signals from the engine controller and drives the fuel feed pump. • Drives the fuel feed pump by operating the toggle switch to bleed air from the fuel route after replacement of the fuel filter etc. • The air in the fuel route is bled by driving the fuel feed pump according to the setting of the built-in timer. • Drive pattern of fuel feed pump: Perform the cycle of “Drive pump (30 sec) o Stop pump (10 sec)” 10 times, and then stop automatically

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10 Structure and function Engine wiring harness

Engine wiring harness

(ENG125-AK51-041-K-00-A)

a The shape is subject to machine models.

1. Engine pressure sensor 2. EGR valve lift sensor 3. Fuel dosing pressure sensor 4. Charge pressure sensor 5. KVGT position sensor 6. KVGT speed sensor 7. Ambient pressure sensor 8. Coolant temperature sensor 9. Charge temperature 10. Common rail pressure sensor 11. Ne sensor 12. Engine controller

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10 Structure and function Engine wiring harness

13. Supply pump 14. Bkup speed sensor (Camshaft)

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10 Structure and function Engine controller

Engine controller

Function

(PC220-AP70-041-K-00-A)

(ENG107-AP70-042-K-00-A)

• The engine controller CM2250, co-developed by Komatsu and Cummins, is adopted. • It performs calculations based on input signals from various sensors to output signals for optimized engine control. • The engine controller shares information with other controllers on the machine through the network (CAN) and optimally controls the engine according to the machine conditions. • By mounting the controller on the engine, serviceability in the field is improved. • The controller is mounted with rubber vibration isolators to reduce the effect of vibration.

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10 Structure and function Engine controller

Engine controller system diagram

Input and output signals

(ENG125-AP70-052-K-00-A)

(ENG125-AP70-03C-K-00-A)

• The following is the list of the symbols used for signal category in the input/output signal table. A: Electric power supply B: Input C: Ground/Shield/Return D: Output E: Communication DRC26–60P(1) [ECM J1 (CN-CE01)] Pin No. 1 2 3 4 5 6 7 8 9 10 125E-6 SERIES

Signal name (*1) Engine pressure sensor Crankcase pressure sensor (*1) Charge temperature sensor Intake temperature sensor CAN_C(+) CAN_B(+)(KOMNET/r) Bkup speed sensor (+) (*1)

Signal category – B B – B B E E B –

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10 Structure and function Engine controller

Pin No. 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Signal name (*1) (*1) GND Coolant temperature sensor Charge pressure sensor Ambient pressure sensor CAN_C(-) CAN_B(-)(KOMNET/r) (*1) (*1) Sensor power supply (12 V) GND Mass air flow and temperature sensor (*1) (*1) Ne (crankshaft) speed sensor (+) (*1) (*1) (*1) (*1) (*1) GND (*1) (*1) (*1) Sensor power supply (5 V) Ne (crankshaft) speed sensor (-) (*1) (*1) (*1) (*1) (*1) Injector #4 (+) Injector #5 (+) Injector #6 (+) Injector #3 (+) Injector #2 (+) Injector #1 (+) (*1) (*1) (*1) (*1) Injector #4 (–) Injector #5 (–) Injector #6 (–) Injector #3 (–) Injector #2 (–) Injector #1 (–) GND Sensor power supply (5 V)

Signal category – – C B B B E E – – A C B – – B – – – – – C – – – A C – – – – – D D D D D D – – – – C C C C C C C A

*1: Never connect these pins. Malfunctions or failures may occur. DRC26–60P(2) [ECM J2 (CN-CE02)]

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Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 125E-6 SERIES

Signal name Supply pump PCV2(+) Supply pump PCV2(+) (*1) Supply pump PCV1(+) Supply pump PCV1(+) EGR actuator (+) (*1) Fuel doser solenoid valve 2(+) Fuel doser solenoid valve 1(+) KVGT actuator (+) (*1) (*1) (*1) (*1) (*1) EGR actuator (-) (*1) Fuel doser solenoid valve 1, 2(-) (*1) KVGT actuator (-) GND (*1) (*1) CAN_B(+) CAN_B(-) (*1) (*1) (*1) (*1) Sensor power supply (5 V) Sensor power supply (5 V) KVGT speed sensor (+) KVGT speed sensor (-) Exhaust manifold pressure sensor (*1) Doser fuel Pressure sensor (*1) KVGT position sensor (*1) (*1) (*1) (*1) (*1) (*1) (*1) GND GND (*1) (*1) Fuel doser(+) (*1) (*1)

Signal category D C – D C D – D D D – – – – – C – C – C C – – E E – – – – A A B C B – B – B – – – – – – – C C – – D – –

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10 Structure and function Engine controller

Pin No. 53 54 55 56 57 58 59 60

Signal name (*1) (*1) Common rail pressure sensor (*1) (*1) (*1) EGR valve lift sensor Fuel doser(-)

Signal category – – B – – – B C

*1: Never connect these pins. Malfunctions or failures may occur. DRC26–60P(3) [CN-CE03] Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

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Signal name continuous power supply (24 V) continuous power supply (24 V) Starting switch ACC signal Intake air heater relay (+) (*1) (*1) (*1) (*1) System operating lamp (*1) continuous power supply (24 V) continuous power supply (24 V) GND Electrical fuel feed pump (*1) (*1) CAN_A(+)(KOMNET/c) CAN_A(-)(KOMNET/c) GND (*1) GND GND (*1) (*1) (*1) (*1) (*1) (*1) (*1) (*1) GND GND (*1) (*1) (*1) (*1) (*1) (*1) (*1) (*1) GND

Signal category A A B D – – – – D – A A C D – – E E C – C C – – – – – – – – C C – – – – – – – – C 125E-6 SERIES

10 Structure and function Engine controller

Pin No. 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Signal name Sensor power supply (5 V) GND (*1) KDOC inlet temperature sensor (*1) (*1) KDOC outlet temperature sensor Idle validation signal 1 Idle validation signal 2 Throttle signal Sensor power supply (5 V) (*1) KDPF outlet temperature sensor KDPF differential pressure sensor (*1) (*1) KDPF outlet pressure sensor (*1) (*1)

Signal category A C – B – – B B B B A – B B – – B – –

*1: Never connect these pins. Malfunctions or failures may occur.

125E-6 SERIES

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10 Structure and function Sensor

Sensor

(ALL-E700-001-P-00-A)

Sensors layout drawing

10-106

(ENG125-AK50-04D-K-00-A)

125E-6 SERIES

10 Structure and function Sensor

List of sensors No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

(ENG125-AK50-056-K-00-A)

Sensor KVGT speed sensor KVGT position sensor KDOC inlet temperature sensor KDPF differential pressure and outlet pressure sensor Crankcase pressure sensor Manifold pressure sensor Coolant temperature sensor Engine oil level sensor Air cleaner clogging sensor KDOC outlet temperature sensor KDPF outlet temperature sensor Common rail pressure sensor Ambient pressure sensor Ne (crankshaft) speed sensor Bkup (camshaft) speed sensor Engine oil pressure switch Mass air flow and temperature sensor EGR valve lift sensor Charge temperature sensor Dosing fuel pressure sensor

Engine oil pressure sensor

Connector label name VGT_REV SVGT TEMP1 E25 PCCV PIM TWTR P44 E26[TOUT] TEMP2 TEMP3 PFUEL PAMB NE G POIL MAF SEGR TIM HC

(PC400-ABK5-041-K-00-A)

1. Connector 2. Sensor 3. O-ring

Function

(PC400-ABK5-042-K-00-A)

• This oil pressure sensor, installed in the cylinder block, It detects engine oil pressure to output variable voltage.

KVGT speed sensor

(ENG125-AAQ4-041-K-00-A)

KVGT: Abbreviation for KOMATSU Variable Geometry Turbocharger

125E-6 SERIES

10-107

10 Structure and function Sensor

1. Sensor 2. O-ring 3. Connector

Function

(ENG125-AAQ4-042-K-00-A)

• This sensor, installed to KVGT in the engine, outputs the pulse voltage by means of the rotation of KVGT turbine.

VGT position sensor

(ENG-AAQ3-041-K-00-A)

VGT: Abbreviation for Variable Geometry Turbocharger

1. O-ring (small) 2. O-ring (large) 3. Sensor 4. Connector

Function

(ENG-AAQ3-042-K-00-A)

• This sensor, installed to VGT in the engine, detects the location of the nozzle ring which is built in VGT to output the corresponding variable voltage. Output characteristics • The relation between stroke and output voltage is as shown in the following graph.

10-108

125E-6 SERIES

10 Structure and function Sensor

Ambient pressure sensor

(ENG-AAP2-041-K-00-A)

1. Connector 2. Sensor

Function

(ENG-AAP2-042-K-00-A)

• This sensor, installed to the air intake cover at the engine top side, detects the ambient pressure to output the corresponding variable voltage. Output characteristics

125E-6 SERIES

10-109

10 Structure and function Sensor

Charge temperature sensor

Function

(ENG125-AAM4-041-K-00-A)

(ENG125-AAM4-042-K-00-A)

• The charge temperature sensor detects the intake air temperature (boost temperature) and sends it to the engine controller. • The thermistor is used as a sensor of which resistance changes according to the temperature. The engine controller applies voltage to the thermistor and senses the temperature by using the voltage divided by the resistance in the computer and the resistance of the thermistor.

Coolant temperature sensor

(ENG-BA87-041-K-00-A)

1. Connector 2. Sensor 3. O-ring

Function

(ENG-BA87-042-K-00-A)

• This sensor, installed on the cylinder head of the engine, converts the temperature variation into the resistance variation, and outputs the corresponding signals.

10-110

125E-6 SERIES

10 Structure and function Sensor

Ne (crankshaft) speed sensor

(ENG-AG42-041-K-00-A)

1. O-ring 2. Sensor 3. Connector

Function

(ENG-AG42-042-K-00-A)

• This sensor, installed to the crankshaft pulley on the engine front cover, outputs the pulse voltage due to the gear rotation.

Bkup (camshaft) speed sensor

125E-6 SERIES

(ENG125-AG62-041-K-00-A)

10-111

10 Structure and function Sensor

Function

(ENG125-AG62-042-K-00-A)

• Like the NE speed sensor, it utilizes 0 to 5 V pulses that result from the change in the magnetic lines passing through the sensor. • The disc gear installed to the central part of the camshaft of the high-pressure pump has teeth (cut parts) around it at intervals of 120 deg. • In addition to the above teeth, one more tooth is installed. Accordingly, seven pulses are generated every two revolutions of the engine. • The standard pulse of No. 1 cylinder is recognized by the combination of the NE speed sensor pulse and Bkup speed sensor pulse.

Common rail pressure sensor

(ENG-AE28-041-K-00-A)

1. Connector 2. Sensor

Function

(ENG-AE28-042-K-00-A)

• This sensor, installed to the common rail in the engine, detects the fuel pressure to output the corresponding variable voltage.

Exhaust manifold pressure sensor

(ENG-AAN5-041-K-00-A)

1. O-ring 2. Sensor 3. Connector

Function

(ENG-AAN5-042-K-00-A)

• This sensor, installed to the pressure outlet tube installed to the exhaust manifold of the engine, detects the exhaust pressure to output the corresponding variable voltage.

EGR valve lift sensor

(ENG125-A9S2-041-K-00-A)

EGR: Abbreviation for Exhaust Gas Recirculation

10-112

125E-6 SERIES

10 Structure and function Sensor

1. O-ring (small) 2. O-ring (large) 3. Sensor 4. Connector

Function

(ENG125-A9S2-042-K-00-A)

• The sensor, installed to EGR valve on the engine, detects the EGR valve opening to output the corresponding variable voltage. Output characteristics • The relation between stroke and output voltage is as shown in the following graph.

Mass air flow and temperature sensor

125E-6 SERIES

(ENG-A96H-041-K-00-A)

10-113

10 Structure and function Sensor

1. Connector 2. O-ring 3. Sensor

Function

(ENG-A96H-042-K-00-A)

• This sensor is installed to the outlet side of air cleaner, converts the variations of intake air flow and temperature into the resistance variation, and outputs the corresponding signals. a The "MAF (Mass Air Flow)" means the "intake air flow".

KDPF differential pressure and outlet pressure sensor

(ENG-A9HL-041-K-00-A)

KDPF: Abbreviation for KOMATSU Diesel Particulate Filter

1. High-pressure port 2. Low-pressure port 3. Connector 4. Sensor

Function

(ENG-A9HL-042-K-00-A)

• This sensor, installed to KDPF, detects the inlet pressure and outlet pressure of KDPF to output the corresponding variable voltage. • The output pressure difference is the difference between the KDPF inlet pressure which is detected at high-pressure port (1) and the KDPF outlet pressure which is detected at low-pressure port (2). • The KDPF outlet pressure is output as a pressure which is detected at low-pressure port (2).

KDOC inlet temperature sensor

(ENG-A9HG-041-K-00-A)

KDOC: Abbreviation for KOMATSU Diesel Oxidation Catalyst

10-114

125E-6 SERIES

10 Structure and function Sensor

1. Sensor 2. Connector

Function

(ENG-A9HG-042-K-00-A)

• This sensor, installed to the inlet side of KDOC which is built in KDPF, converts the temperature variation into the resistance variation, and outputs the corresponding signals.

KDOC outlet temperature sensor

(ENG-A9HH-041-K-00-A)

KDOC: Abbreviation for KOMATSU Diesel Oxidation Catalyst

1. Sensor 2. Connector

Function

(ENG-A9HH-042-K-00-A)

• This sensor, installed to the outlet side of KDOC which is built in KDPF, converts the temperature variation into the resistance variation, and outputs the corresponding signals.

KDPF outlet temperature sensor

(ENG-A9HJ-041-K-00-A)

KDPF: Abbreviation for KOMATSU Diesel Particulate Filter

125E-6 SERIES

10-115

10 Structure and function Sensor

1. Sensor 2. Connector

Function

(ENG-A9HJ-042-K-00-A)

• This sensor, installed to the outlet side of KDPF, converts the temperature variation into the resistance variation, and outputs the corresponding signals.

Crankcase pressure sensor

(ENG-A18C-041-K-00-A)

1. Connector 2. Sensor 3. O-ring

Function

(ENG-A18C-042-K-00-A)

• This sensor, installed to the inlet side of KCCV head portion, detects the crankcase pressure (blowby pressure) to output the corresponding variable voltage.

Engine oil level sensor

(ENG-AB45-041-K-00-A)

1. Connector 2. Bracket 3. Float 4. Switch

10-116

125E-6 SERIES

10 Structure and function Sensor

Function

(ENG-AB45-042-K-00-A)

• This sensor, installed on the side face of the oil pan, turns "OFF" by the lowered float, if the oil level becomes lower than specified.

Air cleaner clogging sensor

(PC-A968-041-K-01-A)

1. Adapter 2. Hood 3. Indicator 4. Connector

Function

(PC-A968-042-K-00-A)

• This sensor is installed on the air cleaner outlet side. The switch is turned to "ON" position, if the air cleaner is clogged and the pressure level drops to the specified level (negative pressure).

Dosing fuel pressure sensor

(PC400-A9JC-041-K-00-A)

1. O-ring 2. Sensor 3. Connector

Function

(PC400-A9JC-042-K-00-A)

• This sensor, which is installed to the dosing fuel solenoid valve assembly, detects the pressure of the fuel supplied to output the corresponding variable voltage.

125E-6 SERIES

10-117

10-118

125E-6 SERIES

SHOP MANUAL

ENGINE 125E-6 SERIES Model

Serial Number

125E-6 SERIES

20 Standard value table 4 20 Standard value table

125E-6 SERIES

20-1

20 Standard value table Table of contents

Table of contents (ALL-0310-002-A-00-A) 20 Standard value table ..................................................................................................................... 20-1 Table of contents ........................................................................................................................ 20-2 Standard service value table........................................................................................................ 20-3 Standard value table for engine ............................................................................................. 20-3 Running-in standard and performance test standard ............................................................... 20-9

20-2

125E-6 SERIES

20 Standard value table Standard value table for engine

Standard service value table (ALL-A000-001-K-00-A) Standard value table for engine

(ENG107-A000-033-K-00-A)

<Applicable machines> PC490LC-10

(ENG125-A000-033-K-01-A)

Performance Engine Item Engine speed

Measurement condition • Coolant temperature: 60 to 102°C

High idle Low idle

Unit rpm

SAA6D125E-6 Standard value Repair limit for new machine ― 1,930 ± 25 1,000 ± 25

―

Air intake and exhaust system Engine Item

Measurement condition

Air intake resistance Whole speed range Boost pressure

At rated horsepower (1,900 rpm)

Exhaust gas temperature

Whole speed range (20°C)

Exhaust gas color

Valve clearance

Engine outlet • Coolant temperature: (between turbocharger and 60 to 102°C KDPF inlet) • Relieve the arm circuit at the arm IN stroke end, and set swing KDPF outlet lock ON • After kept for 5 (exhaust pipe outlet) seconds at normal condition Intake valve Exhaust valve

At high idle EGR valve oil pressure and KVGT oil pressure At low idle

SAA6D125E-6 Standard value Repair limit Unit for new machine Max. 3.73 kPa 7.47 {762} {mmH 2O} {380} Min. 167 kPa 133 {1,000} {mmHg} {1,250} °C

Max. 650

650

Bosch index

Max. 1.5

―

Bosch index

Max. 0.5

―

0.33 0.71 Min. 1.43 {14.6} Min. 1.18 {12.0}

― ―

mm MPa {kg/cm2}

― ―

Main body Engine Item Compression pressure Blowby pressure

125E-6 SERIES

Measurement condition Engine oil temperature: 40 to 60°C Engine speed: 200 to 250 rpm At rated horsepower (when KCCV is disconnected)

SAA6D125E-6 Standard value Repair limit Unit for new machine MPa Min. 2.9 2.0 {20} 2 {kg/cm } {30} kPa Max. 1.96 3.92 {400} {mmH2O} {200}

20-3

20 Standard value table Standard value table for engine

Lubrication system Engine Item

Oil pressure

Oil temperature Oil consumption

Measurement condition At rated horsepower Engine oil SAE5W-30LA temperature: SAE5W-40LA Min. 80°C At low idle SAE10W-30LA Engine oil SAE15W-40LA temperature: Min. 80°C Whole speed range (inside oil pan) At continuous rated horsepower Ratio to fuel consumption

Unit

SAA6D125E-6 Standard value Repair limit for new machine 0.29 to 0.69 {3.0 to 7.0}

0.18 {1.8}

Min. 0.08 {0.8}

0.05 {0.5}

°C

90 to 110

120

Max. 0.15

0.3

MPa {kg/cm2}

Cooling system Engine Item

Measurement condition

Tension of alternator Deflection when pressed with finger force of 98 N {10 kg} and fan belt

20-4

Unit mm

SAA6D125E-6 Standard value Repair limit for new machine Automatic Automatic adjustment adjustment (auto-tensioner) (auto-tensioner)

125E-6 SERIES

20 Standard value table Standard value table for engine

<Applicable machines> HM300–3

(ENG125-A000-033-K-03-A)

Performance Engine Item Engine speed

Measurement condition • Coolant temperature: 59 to 102°C

High idle Low idle

Unit rpm

SAA6D125E-6 Standard value Repair limit for new machine ― 2,220 ± 50 725 (+50/0)

―

Air intake and exhaust system Engine Item

Measurement condition

Air intake resistance Whole speed range Boost pressure

At rated horsepower (2,000 rpm)

Exhaust gas temperature

Whole speed range (20°C)

Exhaust gas color

Valve clearance

Engine outlet • Coolant temperature: (between turbocharger and 59 to 102°C • After kept for 5 KDPF inlet) seconds at KDPF outlet normal (exhaust pipe outlet) condition Intake valve Exhaust valve

At high idle EGR valve oil pressure and KVGT oil pressure At low idle

SAA6D125E-6 Standard value Repair limit Unit for new machine Max. 3.73 kPa 7.47 {762} {mmH 2O} {380} Min. 147 kPa 120 {900} {mmHg} {1,100} °C

Max. 650

650

Bosch index

Max. 1.5

―

Bosch index

Max. 0.5

―

0.33 0.71 Min. 1.43 {14.6} Min. 1.18 {12.0}

― ―

mm MPa {kg/cm2}

― ―

Main body Engine Item Compression pressure Blowby pressure

125E-6 SERIES

Measurement condition Engine oil temperature: 40 to 60°C Engine speed: 200 to 250 rpm At rated horsepower (when KCCV is disconnected)

SAA6D125E-6 Standard value Repair limit Unit for new machine MPa Min. 2.9 2.0 {20} 2 {kg/cm } {30} kPa Max. 1.96 3.92 {400} {mmH2O} {200}

20-5

20 Standard value table Standard value table for engine

Lubrication system Engine Item

Oil pressure

Oil temperature Oil consumption

Unit

SAA6D125E-6 Standard value Repair limit for new machine 0.29 to 0.69 {3.0 to 7.0}

0.18 {1.8}

Min. 0.08 {0.8}

0.05 {0.5}

°C

90 to 110

120

Max. 0.15

0.3

MPa {kg/cm2}

Cooling system Engine Item

Measurement condition

Tension of alternator Deflection when pressed with finger force of 98 N {10 kg} and fan belt

20-6

Unit mm

SAA6D125E-6 Standard value Repair limit for new machine Automatic Automatic adjustment adjustment (auto-tensioner) (auto-tensioner)

125E-6 SERIES

20 Standard value table Standard value table for engine

<Applicable machine> WA470-7

(ENG125-A000-033-K-04-A)

Performance Engine Item Engine speed

Measurement condition • Coolant temperature: 60 to 102°C

High idle Low idle

Unit rpm

SAA6D125E-6 Standard value Repair limit for new machine ― 2,170 ± 50 800 (+50/0)

―

Air intake and exhaust system Engine Item

Measurement condition

Air intake resistance Whole speed range Boost pressure

At rated horsepower (2,000 rpm)

Exhaust gas temperature

Whole speed range (20°C)

Exhaust gas color

Valve clearance

Engine outlet • Coolant temperature: (between turbocharger and 60 to 102°C KDPF inlet) • Torque converter stall • After kept for 5 KDPF outlet seconds at (exhaust pipe outlet) normal condition Intake valve Exhaust valve

At high idle EGR valve oil pressure and KVGT oil pressure At low idle

SAA6D125E-6 Standard value Repair limit Unit for new machine Max. 3.73 kPa 7.47 {762} {mmH 2O} {380} Min. 127 kPa 100 {750} {mmHg} {950} °C

Max. 650

650

Bosch index

Max. 1.5

―

Bosch index

Max. 0.5

―

0.33 0.71 Min. 1.43 {14.6} Min. 1.18 {12.0}

― ―

mm MPa {kg/cm2}

― ―

Main body Engine Item Compression pressure Blowby pressure

125E-6 SERIES

Measurement condition Engine oil temperature: 40 to 60 °C Engine speed: 200 to 250 rpm At rated horsepower (when KCCV is disconnected)

SAA6D125E-6 Standard value Repair limit Unit for new machine MPa Min. 2.9 2.0 {20} 2 {kg/cm } {30} kPa Max. 1.96 3.92 {400} {mmH2O} {200}

20-7

20 Standard value table Standard value table for engine

Lubrication system Engine Item

Oil pressure

Oil temperature Oil consumption

Unit

SAA6D125E-6 Standard value Repair limit for new machine 0.29 to 0.69 {3.0 to 7.0}

0.18 {1.8}

Min. 0.08 {0.8}

0.05 {0.5}

°C

90 to 110

120

Max. 0.15

0.3

MPa {kg/cm2}

Cooling system Engine Item Alternator belt tension

20-8

Measurement condition Deflection when pressed with finger force of 58.8 N {6 kg}

Unit mm

SAA6D125E-6 Standard value Repair limit for new machine 13 to 16

13 to 16

125E-6 SERIES

20 Standard value table Running-in standard and performance test standard

Running-in standard and performance test standard <Applicable machines> PC490LC-10

(ENG125-A000-034-K-00-A)

(ENG125-A000-034-K-01-A)

Running-in standard Engine

min. rpm

1 2 1,000

2 8 1,000

SAA6D125E-6 Procedure 3 2 1,140

N {kg}

0 {0}

360 {37}

947 {97}

1,516 {155}

1,895 {193}

kW {HP}

0 {0}

27 {36}

81 {109}

162 {217}

270 {362}

Item Running time Engine speed Dynamometer load Output

4 3 1,425

5 5 1,900

Test item Specification value (Gross) Engine speed

SAA6D125E-6 Max. speed with Max. torque no load

Min. speed with no load

– rpm N {kg} kW {HP} Nm {kgm}

Dynamometer load Output (Gross) Torque (Gross) Fuel consumption sec/300 cc Coolant °C temperature Lubricating oil °C temperature kPa Lubricating oil pressure {kg/cm2} Exhaust °C temperature

1,900 1,838 to 1,952 {187 to 199} 270 {362}

1,400 2,045 to 2,172 {209 to 221}

1,930 ± 25

1,000 ± 25

–

1,510 {154}

–

80 to 90

90 to 110

290 to 690 {3.0 to 7.0}

190 to 540 {2.0 to 5.5}

290 to 690 {3.0 to 7.0}

Min. 80 {Min. 0.8}

Max. 650

–

a This table shows the standard values obtained by using the JIS correction coefficients. a Since the output and torque in this table are the standard values when the fan is not installed, they are different from the specification values. a This table shows the standard values when the air cleaner and the KDPF are installed and no load is applied to the alternator. a The dynamometer load in this table shows the value when the dynamometer arm is 716 mm long. a Use ASTM No. 1 or No. 2 diesel fuel as fuel. a Use SAE15W-40LA as lubricating oil.

125E-6 SERIES

20-9

20 Standard value table Running-in standard and performance test standard

<Applicable machines> HM300–3

(ENG125-A000-034-K-03-A)

Running-in standard Engine

min. rpm

1 2 725

2 8 1,000

SAA6D125E-6 Procedure 3 2 1,200

N {kg}

0 {0}

331 {34}

827 {84}

1,323 {135}

1,653 {169}

kW {HP}

0 {0}

25 {33}

74 {100}

149 {200}

248 {333}

Item Running time Engine speed Dynamometer load Output

4 3 1,500

5 5 2,000

a This table shows the values when the fan is not installed. a The dynamometer load in this table shows the value when the dynamometer arm is 716 mm long. Performance test standard Engine SAA6D125E-6 Max. speed with Min. speed with Rated horsepower Max. torque Test item no load no load Specification value – (Gross) rpm Engine speed 725(+50/0) 2,000 1,400 2,220 ± 50 N 1,604 to 1,703 2,272 to 2,411 Dynamometer – – load {kg} {164 to 174} {232 to 246} Output kW 248 – – – (Gross) {HP} {333} Torque Nm 1,677 – – – (Gross) {kgm} {171} Fuel – – – – consumption sec/300 cc Coolant °C 80 to 90 80 to 90 80 to 90 80 to 90 temperature Lubricating oil °C 90 to 110 90 to 110 90 to 110 90 to 110 temperature kPa 290 to 690 190 to 540 290 to 690 Min. 80 Lubricating oil pressure {kg/cm2} {3.0 to 7.0} {2.0 to 5.5} {3.0 to 7.0} {Min. 0.8} Exhaust – – °C Max. 650 Max. 650 temperature a This table shows the standard values obtained by using the JIS correction coefficients. a Since the output and torque in this table are the standard values when the fan is not installed, they are different from the specification values. a This table shows the standard values when the air cleaner and the KDPF are installed and no load is applied to the alternator. a The dynamometer load in this table shows the value when the dynamometer arm is 716 mm long. a Use ASTM No. 1 or No. 2 diesel fuel as fuel. a Use SAE15W-40LA as lubricating oil.

20-10

125E-6 SERIES

20 Standard value table Running-in standard and performance test standard

<Applicable machine> WA470-7

(ENG125-A000-034-K-05-A)

Running-in standard Engine

min. rpm

1 2 800

2 8 1,000

SAA6D125E-6 Procedure 3 2 1,200

N {kg}

0 {0}

272 {28}

680 {69}

1,088 {111}

1,360 {139}

kW {HP}

0 {0}

20 {27}

61 {82}

122 {164}

204 {274}

Item Running time Engine speed Dynamometer load Output

4 3 1,500

5 5 2,000

a This table shows the values when the fan is not installed. a The loads for the dynamometer in this table shows the value when the dynamometer arm is 716 mm long. Performance test standard Engine Rated horsepower

Test item Specification value (Gross value) Engine speed

SAA6D125E-6 Max. speed with no load Max. torque Engine speed

Min. speed with no load Engine speed

― rpm N {kg} kW {HP} Nm {kgm}

Dynamometer load Output (Gross value) Torque (Gross value) Ratio to fuel consumption sec/300 cc Coolant °C temperature: Lubricating oil °C temperature kPa Lubricating oil pressure {kg/cm2} Exhaust gas °C temperature

1,450 1,769 to 1,879 {180 to 192}

2,170 ± 50

800 (+50/0)

―

1,307 {133}

―

80 to 90

90 to 110

290 to 690 {3.0 to 7.0}

190 to 540 {2.0 to 5.5}

290 to 690 {3.0 to 7.0}

Min. 80 Min. {0.8}

Max. 650

―

2,000 1,319 to 1,401 {135 to 143} 204 {274}

a This table shows the standard values obtained by using the JIS correction coefficients. a Output and torque in this table show the values when the fan is not installed, and these values differ from specification values. a This table shows the standard values when the air cleaner and the KDPF are installed and no load is applied to the alternator. a The dynamometer load in this table shows the value when the dynamometer arm is 716 mm long. a Use JIS No.2 diesel fuel for the fuel. a Use SAE15W-40LA as lubricating oil.

125E-6 SERIES

20-11

20 Standard value table Running-in standard and performance test standard

20-12

125E-6 SERIES

SHOP MANUAL

ENGINE 125E-6 SERIES Model

Serial Number

125E-6 SERIES

50 Disassembly and assembly 5 50 Disassembly and assembly

125E-6 SERIES

50-1

50 Disassembly and assembly Table of contents

Table of contents (ALL-0310-002-A-00-A) 50 Disassembly and assembly ........................................................................................................... 50-1 Table of contents ........................................................................................................................ 50-2 Related information on disassembly and assembly ........................................................................ 50-3 How to read this manual ....................................................................................................... 50-3 Coating materials list ............................................................................................................ 50-5 Special tool list..................................................................................................................... 50-9 Sketch of special tool.......................................................................................................... 50-11 Disassembly and assembly ....................................................................................................... 50-14 General disassembly of engine ........................................................................................... 50-14 General assembly of engine................................................................................................ 50-35 Removal and installation procedure of supply pump as single component............................... 50-80 Engine front oil seal replacement procedure ......................................................................... 50-85 Engine rear oil seal replacement procedure.......................................................................... 50-88

50-2

125E-6 SERIES

50 Disassembly and assembly Related information on disassembly and assembly

Related information on disassembly and assembly (ALL-3851-001-A-00-A) How to read this manual

(ALL-0320-011-A-00-A)

(Rev.2013.05) Removal and installation of TTTT assembly Special tools • The special tools required for removal and installation work are described in the list as symbols such as A1, ..., X1. Part number, part name, necessity, and quantity are described. • Mark used in the column of necessity are explained below. t: Tools are not substituted, must always be equipped (used). q: Tools extremely useful if available or tools that can be substituted with commercially available tools. • For details and the sketches of the special tools, see "Special tool list" and "Sketches of special tools." Removal • In "Removal" section, the work procedures, precautions and know-how to do the work, and the amount of oil and coolant to be drained are described. • The general tools required for "Removal" are listed as [1], [2], ..., without description of part number, part name, and quantity. • Marks used in "Removal" section are explained below. k : This mark shows safety-related precautions

which must be followed when performing the work.

• The general tools required for "Installation" are listed as [1], [2], ..., without description of part number, part name, and quantity. • Marks used in "Installation" section are explained below. k : This mark shows safety-related precautions

which must be followed when performing the work. a : This mark gives knowledge or precautions when performing the work. 4 : This mark shows the weight of the part or equipment. 2 : This mark shows a specific coating agent to be used. 3 : This mark shows the specified tightening torque. 5 : This mark shows the amount of oil or coolant to be added. • For details of oil or coolant to be added after installation, see Specification "Table of fuel, coolant and lubricants". Disassembly and assembly of TTTT assembly Special tools

Installation

• The special tools required for disassembly and assembly work are described in the list as symbols such as A1, ..., X1. Part number, part name, necessity, and quantity are described. • Mark used in the column of necessity are explained below. t: Tools are not substituted, must always be equipped (used). q: Tools extremely useful if available or tools that can be substituted with commercially available tools. • For details and the sketches of the special tools, see "Special tool list" and "Sketches of special tools."

• The work procedure of "Installation" is in the reversed order to removal unless otherwise specified. • For knowledge and precautions required for "Installation", a [*1] mark is assigned to the "Removal" work procedure to indicate the work item of the installation knowledge or precaution.

Disassembly • "Disassembly" describes the work procedure as well as the precautions, knowledge, and drain amounts of oil and coolant required for the work. • The general tools required for "Disassembly" are listed as [1], [2], ..., without description of part number, part name, and quantity.

a : This mark gives knowledge or precautions when performing the work. [*1]: This mark indicates that knowledge or precautions for the assembly installation work are given in the "Installation" section. 6 : This mark shows the amount of oil or coolant to be drained. 4 : This mark shows the weight of the part or equipment.

125E-6 SERIES

50-3

50 Disassembly and assembly Related information on disassembly and assembly

• Marks used in the section of "Disassembly" are explained below. k : This mark shows safety-related precautions

which must be followed when performing the work. a : This mark gives knowledge or precautions when performing the work. 6 : This mark shows the amount of oil or coolant to be drained. 4 : This mark shows the weight of the part or equipment. Assembly • "Assembly" describes the work procedure as well as the precautions, knowledge, and drain amounts of oil and water required for the work. • The general tools required for "Assembly" are listed as [1], [2], ..., without description of part number, part name, and quantity. • Marks used in the section of "Assembly" are explained below. k : This mark shows safety-related precautions

50-4

125E-6 SERIES

50 Disassembly and assembly Related information on disassembly and assembly

Coating materials list

(ALL-3540-071-A-00-A)

(Rev.2012.11) a The coating materials such as adhesives, liquid gasket, and grease used for disassembly and assembly are listed below. a For coating materials not listed below, use the equivalent of products shown in this manual. Adhesive Komatsu code

Part No.

Capacity

Container

LT-1A

790-129-9030

150 g

Tube

LT-1B

790-129-9050

20 g (contained 2 pieces)

Polyethylene container

LT-2

790-129–9180

50 g

Polyethylene container

Main features and applications • Use to prevent rubber gaskets, rubber cushions, and cork plugs from coming out. • Use for plastic (except polyethylene, polypropylene, tetrafluoroethylene and vinyl chloride), rubber, metal, and nonmetal parts which require immediate and strong adhesion. • Features: Resistance to heat and chemicals • Use to prevent bolts and plugs from coming loose and as sealant.

LT-3

790-129-9060 Set of adhesive and hardener

Adhesive: 1 kg Hardener: 500 g

Can

• Use to bond and seal metal, glass and plastics.

LT-4

790-129-9040

250 g

Polyethylene container

Holts MH705

790-129-9120

75 g

Tube

ThreeBond 1735

790-129-9140

50 g

Polyethylene container

Aron Alpha 201

790-129-9130

2g (contained 5 pieces)

Polyethylene container

Loctite 499

428-99-80070

20 cc

Tube

Loctite 648-50

79A-129-9110

50 cc

Polyethylene container

125E-6 SERIES

• Use to seal plugs for blank holes. • Heat-resistant seal used to repair engines • Instantaneous adhesive • Curing time: From 5 sec. to 3 min. • Use mainly to bond metals, rubbers, plastics, and woods. • Instantaneous adhesive • Quick-curing type (max. strength is obtained after 30 minutes) • Use mainly to bond rubbers, plastics, and metals. • General-purpose instantaneous adhesive with excellent resistance to heat and impact • Use on the bushing mounting faces of axle supports. • Features: Resistance to heat and chemicals • Use to bond high-temperature fit parts.

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50 Disassembly and assembly Related information on disassembly and assembly

Liquid gasket Komatsu code LG-5 ThreeBond 1110F

Part No. 790-129-9080

Capacity

Container

1 kg

Polyethylene container

• • •

LG-6 ThreeBond 1215

790-129-9160

250 g

Tube

• • •

LG-7 ThreeBond 1207C

790-129-9170

150 g

Tube

LG-8 ThreeBond 1207B

419-15-18131

100 g

Tube

LG-9 ThreeBond 1206D

790-129-9310

• • • •

200 g

Tube • •

LG-10 ThreeBond 1206E

790-129-9320

200 g

LG-11 ThreeBond 1121

790-129-9330

200 g

Tube

•

ThreeBond 1211

790-129-9090

100 g

Tube

•

Tube • •

Main features and applications Use to seal various threaded parts, pipe joints, and flanges. Use to seal taper plugs, elbows, and nipples for hydraulic piping. Features: Silicon-based heat and coldresistant sealant. Use to seal flange surface and threaded parts. Use to seal oil pan, final drive case, etc. Features: Silicon-based quick-curing sealant Use to seal flywheel housing, intake manifold, oil pan, thermostat housing, etc. Features: Silicon-based heat, vibration, and shock-resistant sealant. Use to seal transfer case, etc. Use for rough surfaces such as the circle gear top seal which is not clamped by bolts, gaps in the weld which must be caulked, etc. Can be coated with paint. Use as lubricant or sealant when the radiator hoses are put on. Can be coated with paint. Feature: Can be used together with solid gaskets. Use for covers of the transmission case and steering case etc. Liquid gasket used to repair engine

Molybdenum disulfide lubricant Komatsu code

Part No.

Capacity

Container

LM-P

09940-00040

200 g

Tube

LM-S

09995-00250

190 g

Can

50-6

Main features and applications • Use to prevent galling and seizure of press-fitted parts, shrinkage-fitted parts, and threaded parts. • Use to lubricate linkages, bearings, etc. • Spray type • Thin molybdenum disulfide films are made on metal surfaces to prevent the metals from galling. • Use for the drive shaft splines, needle bearings, various link pins, bolts, etc.

125E-6 SERIES

50 Disassembly and assembly Related information on disassembly and assembly

Seizure prevention compound Komatsu code

Part No.

Capacity

Container

LC-G NEVER-SEEZ

—

Can

Capacity

Container

Main features and applications

Various

• Lithium grease with extreme pressure lubrication performance, general purpose type.

400 g x 10 400 g x 20 16 kg

Bellowstype container Can

• Use for parts under heavy load. Caution: • Do not use this grease for rolling bearings like swing circle bearings, etc. and spline. • Use this grease for work equipment pins only when installing them, but do not use it afterward.

400 g 16 kg

Bellowstype container Can

• Higher seizure resistance, heat resistance, and waterproof than molybdenum disulfide grease • Not conspicuous on machine since color is white.

400 g 16 kg

Bellowstype container Can

• Since this grease is biodegradable in short period, it has less impact on microorganisms, animals, and plants.

Main features and applications • Feature: Seizure and galling prevention compound with metallic super-finegrain, etc. • Use for the mounting bolt in the high temperature area of the exhaust manifold and the turbocharger, etc.

Grease Komatsu code

Part No. SYG2-400LI-A G2-LI SYGA-16CNLI G0-LI(*) SYG0-400LI-A *: For cold districts (*) SYG0-16CNLI (*)

Molybdenum disulfide grease LM-G(G2-M)

SYG2-400M SYG2-400M-A SYGA-16CNM

Hyper white SYG2-400T grease SYG2-16CNT G2-T SYG0-400T(*) G0-T(*) SYG0-16CNT(*) *: For cold districts Biogrease SYG2-400B G2-B SYGA-16CNB G2-BT(*) SYG2-400BT(*) *: For use at high SYGA-16CNBT temperature and (*) under high load

G2-S ThreeBond 1855

—

200 g

Tube

G2-U-S ENS grease

427-12-11871

2 kg

Can

125E-6 SERIES

• Feature: Silicon-based grease with wider operating temperature range and superior thermal oxidative stability to prevent deterioration of rubber and plastic. • Use for oil seals of the transmission, etc. • Feature: Urea (organic) grease with heat resistance and long life, inclusion type. • Use for rubber, bearing and oil seal in damper. Caution: Do not mix with lithium grease.

50-7

50 Disassembly and assembly Related information on disassembly and assembly

Primer Loctite 712

Part No.

Capacity

428-99-80080

100 ml

SUNSTAR Paint Surface Primer 580 SUPER SUNSTAR Glass Primer 580 SUPER

417-926-3910

SUNSTAR Paint Surface Primer 435-95

Container Glass container

20 ml

Glass container

20 ml

Glass container

22M-54-27230

20 ml

Glass container

SUNSTAR PRIMER 435-41 for glass

22M-54-27240

150 ml

Steel can

SUNSTAR sash primer GP-402

22M-54-27250

20 ml

Glass container

Komatsu code

Part No.

Capacity

Container

SUNSTAR Penguin Seal 580 SUPER "S" or "W"

417-926-3910

320 ml

Polyethylene container

Sika Japan Sikaflex 256HV

20Y-54-39850

310 ml

Cartridge

SUNSTAR Penguin Super 560

22M-54-27210

320 ml

Ecocart (special container)

Part No.

Capacity

Container

417-926-3920

330 ml

Cartridge

20Y-54-55130

333 ml

Cartridge

Main features and applications • Use to accelerate hardening of instantaneous adhesive. • Use as primer for cab side. (Effective period: 4 months after manufacture) • Use as primer for glass side. (Effective period: 4 months after manufacture) • Use as primer for painted cab sheet metal surface. (Effective period: 4 months after manufacture) • Use as primer for black ceramiccoated glass surface and for hard polycarbonate-coated surface. (Effective period: 4 months after manufacture) • Use as primer for sash (alumite surface treatment). (Effective period: 4 months after manufacture)

For adhered window glass

Komatsu code

For adhered window glass

Adhesive Main features and applications • Use "S" as adhesive for glass in high temperature months (during summer) and "W" in low temperature months (during winter). (Effective period: 4 months after manufacture) • Use as adhesive for glass. (Effective period: 6 months after manufacture) • Use as adhesive for glass. (Effective period: 6 months after manufacture)

Komatsu code SUNSTAR Penguin Seal No.2505 SEKISUI Silicone Sealant 83 GE TOSHIBA SILICONES TOSSEAL381

50-8

22M-54-27220

333 ml

Cartridge

For adhered window glass

Caulking material Main features and applications • Use to seal glass-to-glass joint. (Effective period: 4 months after manufacture) • Use to seal front window. (Effective period: 6 months after manufacture) • Translucent white seal used for joint seals between glasses (Effective period: 12 months after manufacture)

125E-6 SERIES

50 Disassembly and assembly Related information on disassembly and assembly

Special tool list

(ENG125-3530-061-A-00-A)

a Tools with part number 79*T-***-****: are not supplied (to be locally manufactured). a Necessity: t: Tools are not substituted, must always be equipped (used). q: Tools extremely useful if available or tools that can be substituted with commercially available tool. a New/redesign: N: Tools with new part numbers, newly developed for this model. R: Tools, with advanced part numbers, developed by improving existing tools for other models. Blank: Tools that are already used on other models and are usable for the give model, too, without any modification

Disassembly and 1 assembly of engine A 2 assembly Removal and installation of cylinder B head valve spring Removal and installation of piston ring C Removal and installation of cylinder D liner Installation of cylinder E liner Measurement of protrusion of cylinder F liner Installation of piston G assembly Measurement of protrusion of piston H head Adjustment of valve J clearance

Part name

790-501-2001 Engine repair stand t 1 790-901-1240 Adapter

t 1

795-102-2103 Spring pusher

t 1

795-100-1191 Piston ring tool

t 1

795-921-1110

Piston holder

t 1

795-502-1121 Gauge holder

t 1

795-125-1360 Clearance gauge

q 1 q 1

790-331-1110

Removal of engine front seal and engine rear seal

Oil seal puller 795-931-1100 assembly

125E-6 SERIES

795T-5211140 M 2 01010-61650 3 01643-31645 1

Removal and installation of cylinder head valve spring Removal and installation of piston ring Removal and installation of cylinder liner Press-fitting of cylinder liner Measurement of protrusion of cylinder liner Insertion of piston assembly Measurement of protrusion of piston head Adjustment of valve clearance Angle tightening of connecting rod cap bolt, main cap bolt, and cylinder head bolt Removal of engine front seal and engine rear seal

795-225-1520 Cylinder liner driver t 1 795-790-4100 Depth gauge

Wrench

q 1

Push tool

t 1

Bolt Washer

t 3 t 9

Detail of work, remarks

Setting of cylinder block

795-220-1000 Cylinder liner puller t 1

Torque plus angle method for bolt

Installation of engine front seal

Sketch

Part number

New/redesign

Symbol

Q'ty

Work

Necessity

a Tools marked with Q in the sketch column have the sketches. (See "Sketches of special tools")

Press-fitting of engine front seal

50-9

50 Disassembly and assembly

t 1

Bolt Washer Push tool Bolt Washer

t t t t t

Push tool

t 1

Bolt Washer Standard puller Bolt Washer

t t t t t

795T-4111510

Screwdriver

t 1

795T-6212820

Push tool

t 1

795T-6212810

Installer

t 1

2 3 4 N 5 6 7

Removal of supply pump

8 9 1 P 2 3

Installation of oil seal for valve stem in cylinder head Installation of exhaust connector

50-10

795T-4211340 01010-61635 01643-31645 795-931-1220 01010-41650 01643-31645 795T-4211320 01010-61645 01643-31645 795-630-5500 01010-81090 01643-31032

3 3 1 3 3

Sketch

Part name

Push tool

Installation of engine rear seal

Part number

New/redesign

Symbol

Q'ty

Work

Necessity

Related information on disassembly and assembly

Detail of work, remarks

Press-fitting of standard oil seal (with guide)

Press-fitting of sleeved Q oil seal

3 9 1 2 2

Removal of supply pump drive gear Press-fitting of valve N Q system oil seal Press-fitting of exhaust connector seal Measurement of N Q exhaust connector installed dimensions N Q

125E-6 SERIES

50 Disassembly and assembly Related information on disassembly and assembly

Sketch of special tool

(ENG125-3531-066-A-00-A)

Note: Komatsu does not accept any responsibility for special tools manufactured according to these sketches. M1 Push tool

N1 Push tool

125E-6 SERIES

50-11

50 Disassembly and assembly Related information on disassembly and assembly

Note: Komatsu does not accept any responsibility for special tools manufactured according to these sketches. N7 Push tool

Q Screwdriver

50-12

125E-6 SERIES

50 Disassembly and assembly Related information on disassembly and assembly

Note: Komatsu does not accept any responsibility for special tool manufactured according to this sketch. S1 Push tool

S2 Installer

125E-6 SERIES

50-13

50 Disassembly and assembly Disassembly and assembly

Disassembly and assembly (ENG107-A000-001-K-00-A) General disassembly of engine

(ENG125-A000-530-K-00-A)

a Before starting your work, check the shapes, quantity, locations, etc. of the parts depend on the machine model. 1. Preparation work Before disassembling the engine, check its parts for cracking, damage, etc. and clean it generally and carefully for accurate inspection of its parts and quick disassembly and assembly. a Before cleaning the engine, carefully seal the openings or remove electric parts and wiring connectors so that water does not enter them. 2. Engine assembly 1) Set engine assembly (1) on a rigid and stable stand [1]. 4 Engine assembly (1):

a The shape of KDPF bracket (1) depends on the applicable machine model.

4. Starting motor assembly Remove mounting bolt (1) and remove starting motor assembly (2).

1,800 kg a The weight of engine assembly (1) depends on the applicable machine model. 2) Drain the coolant and engine oil. 6 Engine oil: approx. 40 l a The quantity of the engine oil depends on the applicable machine model. 5. Alternator assembly 1) Remove alternator belt (1) according to the following procedure. 1] Set wrench [1] to portion (a) of tension assembly (2) (width across flats: 12.7 mm). 2] Turn wrench [1] anticlockwise when seen from the front of engine, and remove alternator belt (1). k Rotate wrench [1] after making sure it

3. KDPF bracket Remove KDPF bracket (1).

is securely set to portion (a) of tensioner assembly (2). (If you try to rotate the wrench before it is securely attached, it can disengage and cause serious physical injuries due to the strong spring force of tensioner assembly (2).) k After removing alternator belt (1),

return tensioner assembly (2) slowly and carefully.

50-14

125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

k Take care not to get your fingers

caught between the pulley and alternator belt (1) during work.

7. EGR cooler

2) Remove tensioner assembly (2) from tensioner bracket (5). 3) Remove alternator assembly (4) from tensioner bracket (5) and alternator bracket (6). 4) Remove tensioner bracket (5) from the front cover. 5) Remove alternator bracket (6) from the cylinder block.

1) Disconnect KVGT oil drain tube (1). 2) Disconnect air vent tube (2) and EGR coolant tubes (3) and (3a).

3) Disconnect two EGR air vent tubes (4).

6. Oil tube for KVGT hydraulic actuator 1) Disconnect EPC valve connector VGT-SOL (1). 2) Disconnect oil tube (2) for the KVGT hydraulic actuator. 4) Disconnect air heat insulation plate (5) and EGR piping (6). a The installation of the heat insulation plate (5) depends on the machine model. 5) Remove EGR piping (7) and EGR cooler (8).

125E-6 SERIES

50-15

50 Disassembly and assembly Disassembly and assembly

3) Remove the clamp and disconnect coolant tube (4).

4) Disconnect the following connectors. (7): SVGT (8): VGT-REV

6) Remove bracket (9).

5) Disconnect the following hoses and tubes. 1] Remove the clamps and disconnect coolant tube (5) and fuel hose (6) for fuel doser. 2] Remove cover (5a) and disconnect two KVGT wiring harnesses (5b) from wiring harness bracket (5c). 8. KVGT and exhaust manifold assembly 1) Remove dosing fuel solenoid valve assembly cover (1).

6) Remove bracket (9).

2) Disconnect connector TWTR (2) and remove bracket (3).

50-16

125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

7) Remove three brackets (10) and wiring harness clamp bracket (11).

11)Sling KVGT and exhaust manifold assembly (15) and remove 18 mounting bolts (16). 12)Lift and remove KVGT and exhaust manifold assembly (15). 4 KVGT and exhaust manifold assembly (15): 65 kg

8) Remove the clamp and disconnect KVGT lubricating oil tube (12).

9. Air vent tube Remove air vent tube (1).

9) Remove bracket (13).

10.Wiring harness assembly

10)Remove the clamp and disconnect KVGT coolant return tube (14). 125E-6 SERIES

1) Disconnect the following connectors. (7): PCV1 (8): PCV2 (9): G (10): PO1L (11): SEGR (12): EGR-SOL

50-17

50 Disassembly and assembly Disassembly and assembly

(4): PDOSER (5a): SOV1 (5b): SOV2 (6): Fuel injector connectors CN1 to CN6 (on each cylinder head)

(1): PAMB (2): SVGT (Remove connector from the holder.) (3): VGT-REV (Remove connector from the holder.)

3) Loosen two lock bolts (20) for connectors ECMJ1 (17) and ECMJ2 (18). 4) Disconnect the following connectors. (15): PFUEL (16): NE (17): ECMJ1 (18): ECMJ2 5) Remove wiring harness assembly (19).

11.Oil filter 1) Remove two clamps (1) and two head tubes (2). 2) Remove the mounting bolts on the oil filter head side and remove oil filter and head assembly (3). 3) Remove upper bracket (4) and lower bracket (5).

2) Remove engine controller cover (14). a The engine control cover (14) varies depending on the machine model.

50-18

125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

12.Fuel pre-filter 1) Disconnect two head tubes (1). 2) Remove the mounting bolts on the fuel prefilter head side and remove fuel pre-filter and head assembly (2).

14.Dosing fuel solenoid valve assembly Remove dosing fuel solenoid valve assembly (1).

15.KCCV ventilator

3) Remove bracket (3).

1) Disconnect two upper hoses (1) and coolant tube (2). 2) Disconnect coolant tube (3) and lower drain hose (4). 3) Remove KCCV ventilator (5). a On some machine models, KCCV ventilator (5) may be mounted on the machine side.

13.Fuel filter a On some machine models, the fuel pre-filter may be mounted on the machine side. 1) Disconnect fuel filter head tubes (1), (2), (3), and (4). 2) Remove fuel filter and head assembly (5).

125E-6 SERIES

50-19

50 Disassembly and assembly Disassembly and assembly

4 Mixing connector (2): 35 kg

16.EGR valve 1) Remove EGR valve oil drain tube (1a). 2) Remove oil tube (1b) for the EGR valve hydraulic actuator. 3) Remove EGR valve (2).

17.Air intake connector 1) Remove bracket (1).

2) Sling mixing connector (2) and remove the mounting bolts. 3) Lift and remove mixing connector (2).

50-20

18.Fuel spill tube Disconnect fuel spill tube (1).

19.Fuel high-pressure pipe 1) Remove bracket (1).

2) Remove clamp (2). 3) Remove fuel spray prevention cap (3).

125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

4 Air intake manifold (3): 30 kg

4) Remove 10 clamps (4). 5) Disconnect six fuel high-pressure pipes (5). 21.Engine controller 1) Disconnect ground cable (1). 2) Remove the mounting bolts and remove engine controller (2).

20.Air intake manifold 1) Remove bracket (1) and oil filler pipe (2). a The shapes of (1) and (2) mentioned above differ depending on the machine model.

22.Engine controller cooler 1) Disconnect two fuel hoses (1). 2) Remove two wiring harness clamps (2). 3) Remove the four mounting bolts and remove engine controller cooler (3).

2) Sling air intake manifold (3) and remove 24 mounting bolts. 3) Lift and remove air intake manifold (3).

4) Remove three clamps (4). 5) Remove fuel spray prevention cap (5) on the fuel high-pressure pipe on the common rail. 6) Disconnect two fuel high-pressure pipes on common rail (6). 7) Disconnect overflow tube (7). 8) Remove dipstick pipe clamp (8). 125E-6 SERIES

50-21

50 Disassembly and assembly Disassembly and assembly

9) Disconnect fuel hose (9) for the fuel doser pump.

24.Supply pump assembly 10)Sling bracket (10). 11)Remove the mounting bolts and lift and remove bracket (10).

1) Disconnect lubricating oil tube (1). 2) Disconnect fuel tubes (1a) and (1b).

a Remove bracket (10) with fuel doser pump (11) attached. 4 Bracket (10): 25 kg

3) Remove cover (2). 4) Rotate the crankshaft in the normal direction (counterclockwise seeing from the flywheel side) to set center point (a) between stamps 2/5TOP and 3/4TOP of damper (3) to pointer (4).

23.Common rail 1) Remove two mounting bolts (1) and common rail (2). 2) Remove four mounting bolts (3) and bracket (4).

a At this time, the stamp of 1/6 TOP is almost at the bottom. a At this time, check that the forcing tap of the drive gear aligns with the mounting bolt hole of cover (2). (If it is not, rotate the crankshaft one more turn.) a At this position, the key of the supply pump shaft is rotated clockwise 15 degrees from the top.

50-22

125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

5) Remove mounting nut (5). 6) Install tools P1, P2, and P3 and tighten the center bolt of P1 to pull out the supply pump drive gear from the shaft. a Keep tools P1, P2, and P3 installed to prevent the supply pump drive gear from coming off.

26.Dipstick pipe Remove dipstick pipe (1). a Put a match mark between dipstick pipe (1) and the cylinder block to indicate the mounting position of the dipstick pipe.

27.Oil cooler assembly 1) Remove drain hose (1a). 7) Remove bracket (6). 8) Remove four mounting bolts (7) and remove supply pump assembly (8). a Keep tools P1, P2, and P3 installed to prevent the supply pump drive gear from coming off.

2) Remove the mounting bolts and remove oil cooler assembly (1) by using guide bolt [1].

25.Fuel block 1) Remove fuel block (1). 2) Remove bracket (2).

125E-6 SERIES

50-23

50 Disassembly and assembly Disassembly and assembly

28.Engine repair stand adapter (installation) Install tool A2.

31.Rocker arm and shaft assembly 1) Loosen lock nut (3) and fully loosen adjustment screw (2). 2) Remove mounting bolt (4) and remove rocker arm and shaft assembly (1).

29.Cylinder head cover Remove cylinder head cover (1). 32.Push rod Remove 12 push rods (1).

30.Fuel injector wiring harness 1) Fully loosen two capture nuts (2) on the head of fuel injector (1). a Loosen capture nuts (2) alternately. 2) Loosen mounting bolt (3) of the wiring harness fixing holder.

33.Fuel injector Remove holder mounting bolt (3) of fuel injector (1) and remove fuel injector (1) and holder (2) together. a Note the cylinder number for the removed fuel injectors and store them in order. a Never grip the solenoid valve at the top of fuel injector (1) with pliers, etc.

50-24

125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

a Be careful not to damage or remove QR code tab (4) on the top of fuel injector (1).

36.Rocker arm housing Remove rocker arm housing (1). 34.Cross head 1) Remove 12 crossheads (1).

37.Thermostat housing and water pump 35.Fuel injector wiring harness connector 1) Remove mounting bolts (2) for the fuel injector wiring harness connector (1). 2) Remove wiring harness from holder (3), and remove holder (3) from rocker housing (4).

1) Remove pins (1). 2) Use bar [1] to push up connector tube (2). a Apply bar [1] to the flange of connector tube (2) to pry off the tube. 3) Disconnect connector (6). 4) Remove thermostat housing (3). a The shape of thermostat housing (3) differs depending on the machine model.

3) Remove wiring harness connector of fuel injector (1) by pushing it from the inside of rocker housing (4) toward the outside. 4) Remove O-ring (5) from the rocker housing.

125E-6 SERIES

50-25

50 Disassembly and assembly Disassembly and assembly

5) Remove the mounting bolts and remove water pump (4).

40.Cam follower 1) Remove 12 mounting bolts (1) and remove six cam followers (2). 2) Remove dowel pins (3).

38.Front hanger 1) Disconnect coolant tube (1). 2) Remove the mounting bolts and remove front hanger (2).

39.Cam follower cover Remove three cam follower covers (1).

41.Cylinder head assembly (removal) 1) Remove seven each of mounting bolts (2) of cylinder head assembly (1). 2) Using eyebolts [1], lift off cylinder head assembly (1). 4 Cylinder head assembly (1): 20 kg 3) Remove six cylinder head gaskets (3).

50-26

125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

4) Turn the cylinder head sideways and remove valve (6). a Check and record the combinations of the valves and cylinder heads.

42.Cylinder head (disassembly) 1) Using tool B, compress valve spring (1) to remove valve cotter (2). 2) Remove upper seat (3) and valve spring (1). 43.Engine repair stand (installation) 1) By using lifting tools, lift the engine and set the previously installed tool A2 to tool A1. Tighten the mounting bolts.

44.Speed sensor Remove speed sensor (1).

3) Remove oil seal (4) and remove lower seat (5).

125E-6 SERIES

50-27

50 Disassembly and assembly Disassembly and assembly

4 Engine oil pan (1): 25 kg

45.Engine oil pressure sensor Remove engine oil pressure sensor (1). 3) Remove the mounting bolts, and then remove bracket (3) and oil strainer (2).

46.Coolant temperature sensor Remove coolant temperature sensor (1). 48.Flywheel 1) By using eyebolt [1], sling flywheel (1). 2) Remove the six mounting bolts and pull out the dowel pin. 3) By using guide bolt [2], pull out and lift and remove flywheel (1). 4 Flywheel (1): 50 kg

47.Engine oil pan and oil strainer 1) Turn the engine sideways, and sling engine oil pan (1) with lifting tool [5]. 2) Remove the mounting bolts and lift and remove engine oil pan (1).

49.Flywheel housing 1) By using eyebolts [1], sling flywheel housing (1). 2) Remove ten mounting bolts (2).

50-28

125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

3) Pull flywheel housing (1) off the dowel pin of the cylinder block. 4 Flywheel housing (1): 70 kg

1) By using eyebolts [1], sling front support bracket (1). 2) Remove the mounting bolts, and then lift and remove front support bracket (1). 4 Front support bracket (1): 50 kg a The shape of front support bracket (1) varies depending on the machine model.

50.Engine rear seal Remove engine rear seal (1) from the flywheel housing. 53.Boost pump, EPC valve 1) Remove boost pump (1). 2) Remove EPC valve (2).

51.Damper and pulley assembly 1) By using lifting tool [1], sling damper and pulley assembly (1). 2) Remove six mounting bolts. 3) By using guide bolts [2], sling and remove dumper and pulley assembly (1). 4 Damper and pulley assembly (1): 25 kg

54.Front cover 1) Remove four mounting bolts (1) on the back. 2) By using eyebolts [1], sling front cover (2). 3) Remove the mounting bolts, and lift and remove front cover (2).

52.Front support 125E-6 SERIES

50-29

50 Disassembly and assembly Disassembly and assembly

4 Front cover (2): 35 kg

a Pull out the camshaft slowly, while rotating it, not to damage the cam bushing.

57.Idler gear (small) 1) Remove mounting bolt (1) and remove plate (2) and idler gear (3).

4) Remove tools P1, P2, and P3 which are installed in step 24. 6), then remove the supply pump drive gear. 55.Engine front seal Remove engine front seal (1) from the front cover.

56.Camshaft 1) Remove two mounting bolts (1) and remove camshaft (2).

50-30

2) Remove shaft (4).

58.Engine oil pump Remove four mounting bolts (1) and remove engine oil pump (2).

125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

a Before removing the piston and connecting rod assembly, measure the side play of big end (a) of the connecting rod with dial gauge [1].

59.Idler gear (large) Remove mounting bolt (1) and remove shaft (2), idler gear (3), and plate (4). 1) Remove the carbon from the upper wall of the cylinder liner with fine sandpaper. 2) Rotate the crankshaft to set the piston to be removed to the bottom dead center. 3) Check that there are identification stamps (b) on the camshaft side of the connecting rod and cap. a The stamps on the connecting rod and cap must be the same. a If there are not stamps, stamp on them before disassembling.

60.Piston cooling nozzle Remove mounting bolt (1) and remove piston cooling nozzle (2) of each cylinder.

4) Remove two mounting bolts (1) of the connecting rod cap. 5) While lightly hitting with a plastic hammer, remove connecting rod cap (2) and connecting rod bearing together.

61.Piston and connecting rod assembly (removal) 125E-6 SERIES

50-31

50 Disassembly and assembly Disassembly and assembly

a When hitting with the plastic hammer, do not damage the threads of mounting bolts (1).

a When storing, assemble the connecting rod and cap loosely and store them together with the connecting rod bearing to prevent any mistake occurring during reassembly.

6) By using wooden rod [2], push in connecting rod end (c) from the engine oil pan side and take out the piston and connecting rod assembly (3) on the cylinder head side. a When taking out the connecting rod, take care not to scratch the inside wall of the cylinder liner with its corners. 7) Remove the other piston and connecting rod assemblies according to the above procedure. a When storing the parts, implement a measures to protect the sliding surfaces of the piston, connecting rod bearing, etc. 62.Piston and connecting rod (disassembly) 1) By using tool [1], remove two snap rings (1). 2) Support connecting rod (2) by hand, pull out piston pin (3) and disconnect piston (4) from connecting rod (2).

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a Before removing crankshaft (1), measure its end play with dial gauge [1].

3) By using tool C, remove piston ring (5). a Store the parts (piston, connecting rod, connecting rod bearings, piston rings, and piston pin) in a set for each cylinder No..

1) Remove two each of mounting bolts (2) of the main cap and remove main caps (3) to (9). 2) Insert mounting bolts (2) into the bolt holes of the main cap and remove the main cap while shaking it.

63.Crankshaft

3) Remove lower thrust bearing (10). (only main cap (9) of No. 7) a Check and record the mounting position of lower thrust bearing (10). 4) Remove lower main bearing (11) from each main cap.

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a Before removing cylinder liner (1), measure its protrusion with plate [1] and tool F. 1) By using tool D, remove cylinder liner (1).

5) By using bolts [2], lift off crankshaft (1). a When removing crankshaft (1), take care not to damage its journals. 4 Crankshaft (1): 110 kg

6) Remove upper thrust bearing (12). (only journal of No. 7) a Check and record the mounting position of upper thrust bearing (12). 7) Remove upper main bearing (13) from each main journal. a Discriminate the parts (main caps, main bearings, thrust bearings) to indicate the positions to be installed, and then keep them by grouping by every cylinder number.

64.Cylinder liner

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General assembly of engine a Before starting your work, check the shapes, quantity, locations, etc. of the parts depend on the machine model.

4 Cylinder block (1): 320 kg

a Clean each part and check for the existence of any dents, damage, cavities, etc. When assembling, check that no oil/coolant passages are clogged. Tightening of bolts by torque plus angle method a Parts to be tightened by torque plus angle method • Cylinder head mounting bolt • Main cap mounting bolt • Connecting rod cap mounting bolt a If a bolt is tightened by the torque plus angle method, permanent deformation occurs to it, thus the number of times of repeated use for the bolt is limited. Accordingly, observe the following before tightening. • Measure the stem length of each bolt and make sure that they are within the allowable limit. If a bolt is out of the allowable limit, do not reuse it; replace it with a new one. • If the number of punch marks on the head of a bolt exceeds the specified number, do not reuse that bolt; replace it with a new one. 1. Cylinder block 1) Install tool A2 to cylinder block (1). 2) Sling cylinder block (1) and set tool A2 to tool A1.

3) Perform preparation work for cylinder block according to the following procedure. a Be sure to perform this preparation work before inserting the cylinder liner. 1] Using a sandpaper, etc., remove rust and scales from faces (A) and (B) until the machined surfaces are exposed. 2] Using a sandpaper (No. 240 or equivalent), polish portion (R) until it is smooth. If portion (R) is sharp or has any burr, polish it with a scraper or sandpaper. Finish this face particularly smoothly so that it does not scratch the O-ring. 3] If face (B) is pitted and cannot be repaired, replace the cylinder block with a new one. 4] If face (A) and portion (R) are pitted, finish them smoothly. 5] Check the counterbore portion and remove all burrs, if there is any. If there is a chips or dirt on face (C), the cylinder liner does not have a tight fit, which may lead to water leakage or improper projection of the cylinder liner, so remove them.

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a If the counterbore portion is drooped, corroded, or pitted, repair it additionally.

a Since engine oil causes the clevis seal and O-ring to swell and deteriorat, apply a small amount of engine oil with a brush just before installing them.

2. Cylinder liner 1) Check that the periphery of the cylinder liner and O-ring grooves are not corroded or pitted. a If any failure is found, replace the cylinder liner with a new part. 2) Install clevis seal (1) and O-rings (2) and (3) to the cylinder liner. a Check that the grooves of the cylinder liner are free from burr, flaw, and dirt. a Replace the clevis seal and O-rings with new ones. a Install clevis seal (1) with the chamfered side down. Press up the clevis seal all around the groove so that it does not be twisted when installed.

3) After installing the O-ring, check it for twisting. If the O-ring is twisted, straighten it by using a smooth rod [1] (outside diameter: approx. 10 mm).

a Referring to the following, install O-rings (2) and (3). • O-ring (2): Whole body is black • O-ring (3): Whole body is red 2 Clevis seal, O-ring: Rubber lubricant (NOF CORPORATION, DISPANOL LH-50) or clean engine oil (SAE30-DH or equivalent)

4) Apply liquid gasket to the fitting portion of the cylinder block counterbore and cylinder liner. a Remove dirt, oil, etc. from the contact faces of the cylinder block counterbore and cylinder liner flange. 2 Cylinder block: Liquid gasket (LG6) • Bead diameter of liquid gasket: 0.8 to 1.6 mm

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• Overlap of liquid gasket (a): 6 ± 6 mm a If the liquid gasket is left for a long period of time after applied, its surface becomes hardened. Accordingly, complete installation of the cylinder block within 50 minutes.

3 Mounting bolt: 127.5 to 147.1 Nm {13 to 15 kgm}

9) Remove the cylinder head and wipe off the excessive liquid gasket which projected from the counterbore portion. 5) Insert cylinder liner (4) into the cylinder block. a Insert cylinder liner (4) slowly so that the outside of the O-rings does not be damaged. 6) Push cylinder liner (4) further into the cylinder block with both hands. a If cylinder liner (4) does not enter the cylinder smoothly, the periphery of the Orings may be broken. In this case, check the cylinder block for existence of burrs. 7) By using tool E, press fit cylinder liner (4) into the cylinder block.

a Be sure to perform steps 8) and 9) since the projected excessive liquid gasket can deform the grommet of the cylinder head gasket. 10)By using plate [1] and tool F, measure the projection of cylinder liner (4). • Projection of cylinder liner: 0.07 to 0.15 mm a If it is out of standard value, take actions by referring to "Maintenance Standards".

3. Crankshaft 8) By using a used cylinder head gasket, tighten the cylinder head temporarily.

a The cylinder block and main bearings are fitting selective parts. (Spare parts are so made that clearance is secured)

a This work is required to prevent the liquid gasket from projecting between the cylinder block and cylinder liner.

1) Drive roll pins (1) into the cylinder block and adjust their protrusion to the following. (only journal of No. 7)

a Observe the following temporary tightening torque and tightening order for the mounting bolts.

• Protrusion of roll pin (1): 1.5 to 1.9 mm 2) Install upper main bearing (2) while fitting its protrusion (b) to notch (a) of the cylinder block.

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a Check that oil hole (C) of upper main bearing (2) is aligned to the oil hole of the cylinder block.

a When installing, take care not to damage the journal of crankshaft (4) by hitting it against the cylinder block.

a Check that no dirt or dust sticks to the back of the upper main bearing (2) before installing.

2 Journal of crankshaft (4): Engine oil (SAE30-DH or equivalent)

2 Upper main bearing inner surface (2): Engine oil (SAE30-DH or equivalent) 3) Install upper thrust bearing (3). (only journal of No. 7)

a When replacing the crankshaft gear, heat the crankshaft gear by using a bearing heater to 150 °C , and fit it quickly.

a Install upper thrust bearing (3) with the grooved face toward the crankshaft. 2 Upper thrust bearing (3): Engine oil (SAE30-DH or equivalent)

6) Drive roll pins (5) into the main cap. (only journal of No. 7) a Protrusion of roll pin (5): 1.5 to 1.9 mm 7) Install lower main bearing (6) to the main cap. a Install lower main bearing (6) while fitting its protrution to the notch of the main cap. a Check that no dirt or dust sticks to the back of the lower main bearing (6) before installing. 2 Lower main bearing (6): Engine oil (SAE30-DH or equivalent) 8) Install lower thrust bearing (7). (only journal of No. 7) a Install lower thrust bearing (7) with the grooved face directed toward the crankshaft. 4) Before installing the crankshaft, check the following.

2 Lower thrust bearing (7): Engine oil (SAE30-DH or equivalent)

• Failure of threaded portions at front and rear of crankshaft (Bolt must be tightened smoothly with the fingers) • Flaw or bruise on crankpin and main journal • Dirt sticking to inside of oil hole 5) By using bolts [1], sling crankshaft (4) and set it to the mounting position. 4 Crankshaft (4): 110 kg 9) Install main cap (8).

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a Check that the stamped No. at the center of the main cap is the same as the journal No. of the cylinder block. a Install main cap (8) with embossed letter (F) at portion (c) directed toward the front of the engine. 2 Journals of crankshaft: Engine oil (SAE30-DH or equivalent)

12)Tighten main cap mounting bolts (9) according to the following procedure. a Tighten mounting bolts (9) in order from the center to the outside. 2 Threaded portion and washer of mounting bolt (9): Engine oil (SAE30-DH or equivalent) 3 Mounting bolt (9): 1st time: 98.1 ± 9.8 Nm {10 ± 1 kgm} 2nd time: 196.1 ± 4.9 Nm {20 ± 0.5 kgm} 3rd time: Using tool K, retighten bolt by 90 deg.(+30 ° /0).

10)Check the main cap mounting bolts for the following. If the following applies to a bolt, do not reuse that bolt but replace it.

a When not using tool K, put paint marks (e) on the main cap and bolt and retighten the bolt by 90 ° (+30 ° /0). 13)After tightening each bolt, put one punch mark (f) on its head. a When using a new bolt, do not put punch mark (f).

• The number of tightening times is six (The number of punch marks on the bolt head is five) • Bolt stem allowable limit (d): Min.159.8 mm

14)Check that crankshaft (4) rotates smoothly. 15)Measure the end play of crankshaft (4) by using dial gauge [1].

11)Tighten main cap mounting bolts (9) alternately to fit main cap (8) perfectly. 125E-6 SERIES

a End play of crankshaft (4): 0.14 to 0.315 mm

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a If it is out of standard value, take actions by referring to "Maintenance Standard".

a When installing the oil ring, take out the expander from inside and fit it to the piston, and then install the oil ring. At this time, make sure that the expander is settled in the ring groove completely.

4. Piston and connecting rod (assembly) a The pistons and cylinder liners are fitting selective parts. (Spare parts are so made that clearance is secured) 1) By using tool C, install piston rings (1). (Install the oil ring, 2nd ring, and top ring in order from the bottom) a Install the top ring and 2nd ring to the piston with the stamped side up. • Mark on top ring: 1H • Stamp of 2nd ring: 2R

2) Set the abutment joints of the piston rings as shown below. a Set the expander joint in the oil ring to the position of 180 ° from the abutment joint of the oil ring.

3) Install snap ring (3) to either side of piston (2). 4) By using an electric oven, heat piston (2) at 100 °C for at least 5 minutes.

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a If an electric oven is not available, heat the piston in hot water of 100 °C for at least 5 minutes.

5) Set connecting rod (4) to piston (2). a Set grade stamp (F) at portion (a) on the side of piston (2) to the front side and set the distinction stamp at portion (b) on the side of the large end of connecting rod (4) to the left side.

a Rotate right and left snap rings (3) to check that they are fitted to the ring grooves perfectly.

8) Install upper connecting rod bearing (6) while setting its projection (d) to notch (c) of connecting rod (4). a Check that no dirt or dust sticks to the back of the upper connecting rod bearing (6) before installing. a Install upper connecting rod bearing (6) while setting its oil hole (f) to oil hole (e) of upper connecting rod (4).

9) Install lower connecting rod bearing (8) while setting its projection (h) to notch (g) of connecting rod cap (7).

6) Insert piston pin (5) into piston (2). 2 Boss of piston: Engine oil (SAE30DH or equivalent) 7) Install snap ring (3) on the opposite side.

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a Check that no dirt or dust sticks to the back of the lower connecting rod bearing (8) before installing.

2 Inside surface of upper connecting rod bearing and inside wall of cylinder: Engine oil (SAE30-DH or equivalent)

5. Piston and connecting rod assembly (installation) 1) Rotate the crankshaft to set the crankpin of the piston to be installed to the bottom dead center. 2) Insert piston and connecting rod assembly (1) in the cylinder block. a Set grade stamp (F) at portion (a) on the side of the piston to the front side of the engine and set the distinction stamp at portion (b) on the side of the large end of the connecting rod to the left side (camshaft side). a Check that the abutment joints of the piston rings are at the positions shown below.

3) Using tool G, reduce the piston rings and push in the head of piston and connecting rod assembly (1) with wooden rod [1].

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a When pushing in piston and connecting rod assembly (1), support the large end of the connecting rod and guide it to the crankpin with the hand on the opposite side to prevent scratching.

4) Install connecting rod cap (2). 2 Inside surface of lower connecting rod bearing: Engine oil (SAE30-DH or equivalent) a Match distinction stamps (c) of connecting rod (3) and connecting rod cap (2). 5) Install connecting rod cap mounting bolts (4).

• The number of tightening times is six (The number of punch marks on the bolt head is five) • Bolt stem is out of allowable limit (d): Min. 84.1 mm

7) Tighten connecting rod cap mounting bolts (4) alternately to fit the connecting rod cap perfectly. 8) Tighten connecting rod cap mounting bolts (4) according to the following procedure. 3 Mounting bolt (4) 1st time: 98.1 ± 4.9 Nm {10 ± 0.5 kgm} 2nd time: Using tool K, retighten bolt by 90 ° (+30 ° /0).

a When not using tool K, put paint marks (e) on the main cap and bolt and retighten the bolt by 90 ° (+30 ° /0). 9) After tightening each bolt, put one punch mark (f) on its head.

6) Check the connecting rod cap mounting bolts for the following. If the following applies to a bolt, do not reuse that bolt but replace it.

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a When using a new bolt, do not put punch mark (f).

6. Piston cooling nozzle 1) Rotate the crankshaft to the following position to install each piston cooling nozzle. • No. 1 at top: No. 1 and No. 6 can be installed • No. 2 at top: No. 2 and No. 5 can be installed • No. 3 at top: No. 3 and No. 4 can be installed 2) While matching the dowel pin, set piston cooling nozzle (2) and secure it with bolt (1). 3 Mounting bolt (1): 27 to 34 Nm {2.8 to 3.5 kgm}

10)Check that the crankshaft rotates smoothly. 11)Measure the side clearance of large end (g) of the connecting rod with dial gauge [2].

a After installing each piston cooling nozzle (2), check that its end is at the center of the notch of the piston.

a Side clearance of large end (g) of connecting rod: 0.2 to 0.375 mm

7. Idler gear (large)

12)By using tool H and dial gauge [2], measure the protrusion of the piston head from the cylinder block top.

1) Install plate (4) to the engine block, 2) Install idler gear (3) and shaft (2), and install mounting bolt (1). a Check that the V-groove is provided on the side of shaft (2) before installing.

a When measuring, press the piston head to eliminate the oil clearance. a Use dial gauge [2] after setting it to zero at the cylinder block top. a Protrusion of piston head: 0.984 to 1.335 mm

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a Install plate (4) with the chamfered side toward the front of the engine.

9. Idler gear (small) 1) Drive in the pin, and install shaft (4). a Check that the V-groove is found on the mating face of shaft (4) with plate (2). 2) Install idler gear (3) and plate (2) with mounting bolt (1) lightly tightened. 3) Mesh idler gear (3) with the engine oil pump gear properly and tighten mounting bolt (1). 3 Mounting bolt (1): 147.0 to 176.4 Nm {15 to 18 kgm}

3) Match timing marks (A) of crankshaft gear (5) and idler gear (3), and then tighten mounting bolt (1). 3 Mounting bolt (1): 245 to 294 Nm {25 to 30 kgm}

8. Engine oil pump 1) Fit the O-ring, install engine oil pump (2), and install four mounting bolts (1).

10.Camshaft 1) Install camshaft (2) to the cylinder block. a Install camshaft (2) while rotating it so that the cam bushing are not scratched.

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a When replacing the cam gear, heat the new cam gear at 220 to 240 °C for less than 30 minutes by using an electric oven, and install it by shrink fit. 2 Journal surface of camshaft (2): Engine oil (SAE30-DH or equivalent) 2) Match timing marks (B) of the camshaft gear and idler gear (small), and then tighten mounting bolts (1).

Install the O-ring and install cam follower cover (1). a When installing the O-ring, do not twist it. 3 Mounting bolt: 9.8 to 12.7 Nm {1.0 to 1.3 kgm}

13.Dipstick pipe Install the collar onto dipstick pipe (1) and fix it with nut (2). 11.Cam follower 1) Drive dowel pins (3) into the cylinder block. 2) Install six cam follower assemblies (2) and tighten mounting bolts (1). 3 Mounting bolt (1): 44 to 59 Nm {4.5 to 6.0 kgm}

3 Nut (2): 44 to 59 Nm {4.5 to 6.0 kgm} a Match the marks put on the cylinder block and dipstick pipe when the dipstick pipe is removed.

14.Thermostat housing and water pump 1) Install O-ring to water pump (4) and tighten the mounting bolts lightly. a Before installing water pump (4), supply engine oil (SAE30-DH or equivalent) to the bearing chamber.

12.Cam follower cover

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2) Install the O-ring to connector tube (2) and install them to thermostat housing (3). 3) Install thermostat (5) and gasket to thermostat housing (3). 4) While pushing up connector tube (2), install thermostat housing (3) and tighten the thermostat housing mounting bolts to the specified torque. 5) By using bar [1], push connector tube (2) into the water pump and fix it with pin (1). a Apply bar [1] to the flange of connector tube (2) to pry the tube up. 6) Tighten the water pump mounting bolts to the specified torque. 7) Install O-ring to connector (6) and tighten the mounting bolts to the specified torque while positioning the connector.

15.Front hanger 1) Install front hanger (2). 2) Install coolant tube (1).

16.Supply pump assembly 1) Set supply pump assembly (1) on the front cover and tighten four mounting bolts (2) lightly. (These are tightened to the specified torque in step 48). 2 Mounting bolt (2): Adhesive (LT-2) 2) Match the keyway of supply pump drive gear (3) with the woodruff key of the shaft. 3) At the same time, match timing marks (C) on supply pump drive gear (3) and cam gear (4), and then tighten mounting nut (5). 3 Mounting nut (5): 176 to 196 Nm {18 to 20 kgm} 4) Install bracket (6). 3 Mounting bolt of bracket (6) (supply pump side): 19.6 to 29.4 Nm {2.0 to 3.0 kgm}

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a Temporarily tighten the mounting bolts on the cylinder block side. (Tighten them to the specified torque in Step 48)

18.Backlash and end play (measurement) a By using dial gauge [1], measure the backlash and end play of each gear. • Standard backlash of each gear Range (mm) Position a 0.105 to 0.325 b 0.105 to 0.325 c 0.116 to 0.359 d 0.105 to 0.337 e 0.082 to 0.389 f 0.076 to 0.366 • Standard end play of each gear Position g h j k m n

Range (mm) 0.05 to 0.17 0.10 to 0.25 0.09 to 0.48 0.04 to 0.38 0.05 to 0.21 0.030 to 0.092

17.Timing mark (check) Check that timing marks (A), (B), and (C) of each drive gear and idler gear are matched securely.

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a If out of standard value, take actions by referring to "Maintenance Standard".

a Length of mounting bolt *1: 95 mm *2: 80 mm *3: 70 mm 3) Install cover (2). 3 Mounting bolt: 98 to 123 Nm {10.0 to 12.5 kgm}

19.Front cover 1) Apply liquid gasket to the front cover mounting face (a) as shown in the drawing below. 2 Front cover (1) mounting face (a): Liquid gasket (LG-7) a Liquid gasket bead diameter at (a): 3 to 5 mm

4) By using dial gauge [2], measure the bottom level difference between cylinder block (5) and front cover (1) at portion (a). a Difference in level at bottom: 0 to 0.275 mm a If it is out of standard value, take actions by referring to "Maintenance Standard".

2) By using eyebolts [1], sling front cover (1) and install it with guide bolt [3]. 4 Front cover (1): 35 kg

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5) Install four mounting bolts (3) on the back.

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3 Mounting bolt (3): 59 to 74 Nm {6.0 to 7.5 kgm}

20.Engine front oil seal a Check that crankshaft end surface corners, sliding surfaces of oil seal lip, and front cover are free from flaws, burrs, rust, etc. 1) Set engine front oil seal (2) to front cover (1) and press fit it with a plastic hammer until oil seal lip (a) enters crankshaft (3). a Take care not to install engine front oil seal (2) in a wrong direction. a When press fitting engine front oil seal (2), hit its periphery evenly so that it does not be deformed. a Take care that oil seal lip (a) does not be caught in crankshaft (3).

2) Install tool M1 and tighten three tools M2 (bolts) evenly until they reach the end to press fit engine front oil seal (2) to front cover (1). a Do not fit tools M3 (washers) to tools M2 (bolts). 3) Remove three tools M2 (bolts) and fit three each of tools M3 (washers) to tools M2 (bolts). 4) Install three tools M2 (bolts) again and tighten them until the end of tool M1 reaches the end of front cover (1) to press fit engine front oil seal (2). a Press fitting distance (b) of engine front oil seal (2) from end of front cover (1): 16 (+1/0) mm

2 Engine front oil seal (2) (50 to 80% full of hollow part of lip): Grease (G2-LI)

a Press fitting distance (c) of engine front oil seal (2) from end of crankshaft (3): 9.2 (+1/0) mm

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a The front support mounting bolts vary depending on the machine model.

21.Boost pump, EPC valve 1) Install three O-rings and EPC valve (2). 3 Mounting bolt: 9.8 to 12.7 Nm {1.0 to 1.3 kgm} 2) Install three O-rings and boost pump (1). 3) Check that the embossed mark (T4) is found at portion (a) of boost pump (1).

23.Damper and pulley assembly 1) By using lifting tool [1], sling damper and pulley assembly (1) and install it by using guide bolt [2]. 2) Install the mounting bolts (there are two types). 4 Damper and pulley assembly (1): 25 kg 3 Mounting bolt (22 mm width across flats, one pc.): 157 to 196 Nm {16 to 20 kgm} 3 Mounting bolt (24 mm width across flats, five pcs.): 245 to 309 Nm {25.0 to 31.5 kgm}

22.Front support bracket 1) By using eyebolts [1], sling front support bracket (1) and install the mounting bolts. 4 Front support bracket (1): 50 kg 2 Mounting bolt of front support bracket (1): Adhesive (LT - 2) 3 Mounting bolt of front support bracket (1): 59 to 74 Nm {6.0 to 7.5 kgm} a The shape of front support bracket (1) varies depending on the machine model.

24.Flywheel housing assembly 1) Apply liquid gasket to portion (a) in the following figure. a Diameter of liquid gasket at part (a): 1 mm 2 Mounting surface of flywheel housing: Liquid gasket (LG-7)

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2) Using eyebolts [1], sling flywheel housing (1) and install it to the cylinder block. a When installing, match the dowel pin. 4 Flywheel housing (1): 70 kg 3) Tighten mounting bolts (2).

4) Measurement of facial runout of flywheel housing 1] Install the magnet stand of dial gauge [3] to the end of the crankshaft. 2] Set dial gauge [3] so that its probe is perpendicular to the end face of the flywheel housing. 3] Rotate the crankshaft one turn on the damper side and read the difference between the maximum and minimum readings of the gauge pointer. a Measure at eight or more points equally spaced peripherally on the end face of the flywheel housing. a Push the crankshaft to the front or rear so that an error is not caused by the end play. a After the crankshaft is rotated by one turn, check that the dial gauge indicates the value at the start of rotation.

a Tighten mounting bolts in the following order.

a Since the gauge pointer moves to both right left, take care not to misread it when the gauge is top, bottom, right, and left position.

a When tightening first, tighten mounting bolts (1), (4) and (2), (9) twice. 2 Threaded portion and seat of mounting bolt: Engine oil equivalent)

(SAE30-DH

a Facial runout: Max. 0.02 mm or

3 Mounting bolt: 1st time: 147 to 235 Nm {16 to 24 kgm} a Impact wrench can be used. 2nd time: 245 to 309 Nm {25 to 31.5 kgm} a Use torque wrench (Do not use impact wrench.) 5) Measurement of radial runout of flywheel housing Similarly to the setting for the facial runout measurement of the flywheel housing, set

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the probe of dial gauge [3] perpendicularly to the spigot joint portion to measure the radial runout. a During the radial runout measurement, no error is caused by the end play of the crankshaft, but the other precautions for facial runout measurement must be observed. a Radial runout: Max. 0.20 mm

6) Using dial gauge [3], measure the bottom level difference between cylinder block (3) and flywheel housing (1) at portion (b). a Bottom level difference: 0 to 0.35 mm a If the measurement result is out of the standard value, take corrective action according to "Structure, function and maintenance standard".

a If the crankshaft is worn to a degree of luster (you can feel the wear with the pad of your finger and the wear depth is a maximum of 10 mm) and there are no scratches, install the standard oil seal. In other cases, install sleeved oil seal. a The left one in the following figure shows the standard oil seal and the right one shows the sleeved oil seal.

2) Installation of standard oil seal a Clean, degrease, and dry the contacting surface against the flywheel housing. a Before installing the oil seal, check that the end corners of crankshaft (4), seal lip sliding surfaces, and housing are free from a flaw, burr, fin, rust, etc. a When installing the engine rear seal, do not apply oil or grease to the hatched portions of the crankshaft and oil seal lip (b). Thoroughly wipe off oil and grease from the crankshaft. a Spare standard engine rear seal (2) has installation guide (6). Never remove that guide before installing the engine rear seal.

25.Engine rear oil seal 1) Selection of oil seal a Check the wear of the crankshaft and select the type of the Teflon seal (laydown lip seal) to install, "standard oil seal" or "sleeved oil seal", depending on the wear of the crankshaft. 1] Put large inside diameter side (c) of installation guide (6) of engine rear seal (2) to the end of crankshaft (4).

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a Take care not to install engine rear seal (2) in a wrong direction.

a When press fitting engine rear seal (2), take care not to scratch the oil seal lip with a tool etc. a After press fitting engine rear seal (2), remove the red sealant layer from its periphery.

2] Push in the outer case end face of engine rear seal (2) evenly. 3] Push in to a degree that engine rear seal (2) does not come off the housing, and then remove installation guide (6). a When removing installation guide (6), take care not to scratch the oil seal lip.

3) Installation of sleeved oil seal a Clean, degrease, and dry the contacting surface against the flywheel housing. a Check that crankshaft end surface corners, sliding surfaces of oil seal lip, and housing are free from flaws, burrs, rust, etc. a Do not apply oil or grease to the hatched parts of the crankshaft, inner cylinder of sleeve (5), and engine rear seal lip (b). Thoroughly wipe off oil and grease from the crankshaft. a Handle the engine rear seal and sleeve (5) as an assembly and never separate them from each other.

4] Install tool N1 and tighten three tools N2 (bolts) evenly until they reach the end to press fit engine rear seal (2). a Do not fit tools N3 (washers) to tools N2 (bolts). a When press fitting the engine rear seal, take care not to scratch the oil seal lip with a tool etc. 5] Remove tools N2 (bolts) and fit one each of tools N3 (washers) to tools N2 (bolts). 6] Install three tools N2 (bolts) to tool N1 again and tighten them until the end of tool N1 reaches the end of crankshaft (4) to press fit engine rear seal (2).

1] Set sleeve and engine rear seal assembly (2) to tool N4.

a Press fitting distance (d) of engine rear seal (2) from end of crankshaft (4): 16.3 ± 0.2 mm

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2 Sleeve inner cylinder surface: Liquid gasket (LG7)

a Press fitting distance (e) of sleeve and engine rear seal assembly (2) from end of crankshaft (4): 16.3 ± 0.2 mm a When press fitting engine rear seal (2), take care not to scratch the oil seal lip with a tool etc. a After press fitting sleeve and engine rear seal assembly (2), remove the red sealant layer from its periphery.

2] Put sleeve (5) of sleeve and engine rear seal assembly (2) to the end face of crankshaft (4) and evenly tighten three tools N5 (bolts) of tool N4 to press fit sleeve and engine rear seal assembly (2). a Install one each of tools N6 (washers) to tools N5 (bolt) and tighten tools N5 (bolts) until they reach the end.

26.Flywheel 1) By using eyebolt [1], sling flywheel (1). By using guide bolt [2], install the flywheel while aligning the dowel pin and the hole. 4 Flywheel (1): 50 kg 2 Threaded portion of mounting bolt and seating surface: Engine oil (SAE30-DH or equivalent) 2) Tighten the mounting bolts in the following order.

3] Replace tool N4 with tool N7 and tighten three tools N8 (bolts) evenly until they reach the end to press fit sleeve and engine rear seal assembly (2). a Do not fit tools N9 (washers) to tools N8 (bolts). 4] Remove tools N8 (bolts) and fit three each of tools N9 (washers) to tools N8 (bolts). 5] Install three tools N8 (bolts) to tool N7 again and tighten them until the end of tool N7 reaches the end of crankshaft (4) to press fit sleeve and engine rear seal assembly (2).

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3 Mounting bolt: 1st time: 147 ± 19.6 Nm {15 ± 2.0 kgm} a Impact wrench can be used 2nd time: 289.1 ± 19.6 Nm {29.5 ± 2.0 kgm}

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1) Install the gasket and install cover (2). 2) Install coolant temperature sensor (1) and plug (3). 3 Coolant temperature sensor (1): 23 ± 3 Nm {2.3 ± 0.3 kgm} 3 Plug (3): 24.5 to 34.3 Nm {2.5 to 3.5 kgm}

28.Speed sensor Install speed sensor (1).

3) By using dial gauge [3], measure the facial runout and radial runout.

3 Mounting bolt (2): 4.9 to 7.9 Nm {0.5 to 0.8 kgm}

a Facial runout: Max. 0.20 mm a Radial runout: Max. 0.15 mm

29.Engine oil pressure sensor Install engine oil pressure sensor (1). 3 Engine oil pressure sensor (1): 23 ± 3 Nm {2.3 ± 0.3 kgm}

27.Coolant temperature sensor

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30.Engine oil pan and oil strainer 125E-6 SERIES

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1) Install the O-ring and oil strainer (2). a Temporarily assemble oil strainer (2) and bracket (3). Tighten the mounting bolts when properly positioned.

32.Engine repair stand adapter (removal) Remove tool A2 from the engine.

2) Put the engine sideways. 3) By using lifting tools [5], sling engine oil pan (1), set the gasket, and then install the engine oil pan. a Install the gasket with the bead facing the oil pan. a Apply liquid gasket (LG-7) to the gasket at the following locations. • Six clinching parts of the gasket • Mating faces of the cylinder block and front cover • Mating faces of the cylinder block and flywheel housing a Install engine oil pan (1) by using the guide bolt.

33.Engine (setting) Set engine (1) on a rigid and stable block [1]. 4 Engine (1): 820 kg

4 Engine oil pan (1): 25 kg

34.Cylinder head (Assembly) 1) Put the cylinder head sideways and install valve (6). 31.Engine repair stand (removal) 1) Set the engine upward. 2) By using lifting tools, sling the engine and separate tool A2 and tool A1. 3) Sling the engine and remove it from tool A1.

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2 Valve (6) (valve stem): Engine oil (SAE30-DH equivalent)

a Hit the valve stem lightly with a plastic hammer to check that the valve cotter is fitted to the groove of the valve stem.

2) Turn the cylinder head upward and install lower seat (5). 3) By using tool Q, install oil seal (4) until driven-in distance (a) is as follows. Driven-in distance (a): 23.4 ± 0.5 mm a Oil seal (4) is of the type that has back pressure lip (4a).

35.Cylinder head assembly (installation) 1) Set six cylinder head gaskets (3) after checking that there is no dust or foreign material on the cylinder head mounting face and inside the cylinders. a Check that the grommet of cylinder head gasket (3) has no peeling or omission.

4) Install valve spring (1) and upper seat (3). 5) By using tool B, compress valve spring (1) and install valve cotter (2).

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2) Check the cylinder head mounting bolts for the following. If the following applies to a bolt, do not reuse that bolt but replace it. • The number of tightening times is six (The number of punch marks on the bolt head is five) • Bolt stem allowable limit (a): Min. 171.4 mm 125E-6 SERIES

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3 Mounting bolt: 1st time: 98.1 ± 9.8 Nm {10 ± 1 kgm} 2nd time: 166.6 to 176.4 Nm {17 to 18 kgm} (Target: 176.4 Nm {18 kgm}) 3rd time: By using tool K, retighten bolt by 90 to 120 ° (Target: 120 ° ).

3) By using eyebolts [1], sling cylinder head assembly (1). Align the dowel pins with the holes, and install the cylinder head assembly. 4 Cylinder head assembly (1): 20 kg

4) Tighten the mounting bolts and auxiliary bolt of the cylinder head assembly. 1] Tighten mounting bolts (1) to (6) in the order shown in the drawing below. 2 Threaded portion of mounting bolt and seating surface: Molybdenum disulfide grease (LM-P) or engine oil (SAE30-DH or equivalent).

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a When not using tool K, put marks (b) on the cylinder head and bolt with paint and retighten the bolt by 90 to 120 ° (Target: 120 ° ). 2] After tightening each bolt, put one punch mark (c) on its head.

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a When using a new bolt, do not put punch mark (c).

2 O-ring (4): Engine oil (SAE30-DH or equivalent) 2) Insert fuel injector wiring harness connector (1) in rocker housing (3) and tighten mounting bolt (2). 2 Mounting bolt (2): Adhesive (LT-2) 3) Fit the wiring harness to holder (5).

3] Tighten cylinder head mounting auxiliary bolt (7). 3 Cylinder head mounting auxiliary bolt (7): 58.8 to 73.5 Nm {6.0 to 7.5 kgm}

36.Rocker arm housing 1) Fit gasket (1) and install rocker arm housing (2). 2) Tighten mounting bolts (3). 3 Mounting bolt (3): 58.8 to 73.5 Nm {6.0 to 7.5 kgm}

38.Cross head 1) Set crosshead (1), loosen lock nut (2), and return adjustment screw (3). 2) Hold the rocker arm contacting surface of crossheads (1) lightly with your fingers to keep crosshead (1) in contact with the valve stem on the push rod side. 3) Tighten adjustment screw (3) until crossheads (1) touches the other valve stem. 4) After adjustment screw (3) touches the valve stem, tighten it further by 20 degrees and tighten lock nut (2) under this condition. 2 Crosshead guide and crosshead top: Engine oil (SAE30-DH or equivalent)

37.Fuel injector wiring harness connector 1) Install O-ring (4) to fuel injector wiring harness connector (1).

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3 Lock nut (2): 58.7 ± 5.9 Nm {6.0 ± 0.6 kgm}

39.Fuel injector a Check that there is no dirt in the fuel injector sleeve. 1) Install bracket (1). 2) Install common rail (2) temporarily.

a Be careful not to damage or remove QR code tab (9) on the top of fuel injector (1).

4) Insert holder (2) into fuel injector (1) and insert inlet connector (5) into the fuel highpressure pipe insertion hole of the rocker housing.

a For positioning of the fuel injector

5) Install the spherical washer to mounting bolt (3) and tighten holder (2) lightly. 2 Spherical washer: Engine oil (SAE30-DH or equivalent) 6) Put fuel high-pressure pipe sleeve (4) to inlet connector (5) and tighten it lightly. a Lightly tighten the common rail side sleeve nuts also. 7) Tighten mounting bolts (3) of holder (2) to the specified torque. a Tighten mounting bolt (3) while pulling the tube of the fuel high-pressure pipe in the opposite direction of fuel injector (1). 3 Mounting bolt (3): 3) Install gasket (6) and O-rings (7) and (8) to fuel injector (1). 2 O-rings (7) and (8): Engine oil (SAE30-DH or equivalent) a Install the fuel injectors to their correct positions by referring to the cylinder numbers noted at removal.

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58.8 to 73.5 Nm {6.0 to 7.5 kgm} 8) Similarly, install the other fuel injectors. 9) After tightening holder (2), remove fuel highpressure pipe sleeve (4) from inlet connector (5). 10)Remove the common rail installed lightly in the above steps.

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3 Mounting bolt (4): 58.8 to 73.5 Nm {6.0 to 7.5 kgm}

40.Push rod Install 12 push rods (1). a Check that the end of push rod (1) is securely fitted to the socket of the cam follower.

42.Fuel injector wiring harness 1) Tighten mounting bolts (3) of the wiring harness fixing holder. 3 Mounting bolt (3): 27.0 to 34.0 Nm {2.8 to 3.5 kgm} 2) Set the wiring harnesses terminal to the head of fuel injector (1) and install two capture nuts (2). a The wiring harness terminal plate can be installed in only one direction. a Tighten capture nuts (2) alternately. 3 Capture nut (2): 2.0 to 2.4 Nm {0.20 to 0.24 kgm}

41.Rocker arm and shaft assembly 1) Set rocker arm and shaft assembly (1) to the rocker housing. a When installing rocker arm and shaft assembly (1), direct its larger mounting hole end down and its ball plug (6) end to the front side of the engine. a Before installing, clean the oil hole of mounting bolt (4) thoroughly. 2) Check that the ball of adjustment screw (2) is fitted in the socket of push rod (5). 3) Tighten mounting bolts (4).

43.Valve clearance (adjustment) a As the valve clearance, adjust the clearance between the crosshead and rocker arm to the following values. • Valve clearance (when the engine is cold) Valve Intake valve Exhaust valve

Valve clearance (mm) 0.33 0.71

a Rotate the crankshaft and adjust the valve clearance of each cylinder in the firing order of 1, 5, 3, 6, 2 and 4.

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1) Rotate the crankshaft in the normal direction (counterclockwise seeing from the flywheel side) to set 1/6TOP stamp (a) of damper (1) to pointer (2), while watching the movement of the valves.

3 Mounting bolt of cylinder head cover (1): 9.8 ± 1.0 Nm {1.0 ± 0.1 kgm}

45.Oil cooler assembly 2) Set tool J between rocker arm (3) and crosshead (4). 3) Tighten adjustment screw (5) and tighten lock nut (6) under the condition that tool J move heavily.

1) Install drain hose (1a).

3 Lock nut (6): 53.0 to 64.7 Nm {5.4 to 6.6 kgm}

a After tightening lock nut (6), check the valve clearance again.

2) Install the gasket to oil cooler assembly (1) and install them by using guide bolts [1].

44.Cylinder head cover Install the O-ring and install cylinder head cover (1). a When installing the O-ring, do not twist it. 46.Fuel block 1) Install bracket (1). 2) Install fuel block (2). a The shape of fuel block (2) varies depending on the machine model.

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3 Sleeve nut of fuel tube (5) (fuel block side): 43 to 47 Nm {4.4 to 4.8 kgm} 3 Sleeve nut of fuel tube (6) (fuel block side): 84 to 132 Nm {8.5 to 13.5 kgm} 3 Joint bolt of fuel tube (6) (fuel doser pump side) 11.6 to 13.6 Nm {1.2 to 1.4 kgm} 47.Common rail 1) Install common rail (2) and tighten mounting bolts (1). 3 Mounting bolt (1): 59 to 74 Nm {6.0 to 7.5 kgm}

48.Fuel high-pressure pipe between supply pump and common rail (installation)

2) Sling and install bracket (3). 4 Bracket (3): 25 kg a Install bracket (3) with fuel doser pump (4) attached.

3) Install fuel tubes (5) and (6). 3 Joint bolt of fuel tube (5) (supply pump side) 14.8 to 19.6 Nm {1.5 to 2.0 kgm}

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a If the taper seal portion of the fuel highpressure pipe joint part has any of the following problems, replace the fuel highpressure pipe with a new one since fuel may leak. • There is visible lengthwise slit (b) or spot (c) in range (a) of 2 mm from the end. • Level difference caused by fatigue which is felt with nail in taper seal end part (d) of 2 mm from end.

1) Install and finger-tighten high-pressure fuel pipes (1) and (2). 2) Install and finger-tighten clamps and brackets for the above-mentioned highpressure fuel pipes (1) and (2). 3) Install and finger-tighten lubricating oil tube (5).

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4) Tighten the sleeve nuts of high-pressure fuel pipes (1) and (2) to the specified torque. 3 Sleeve nut: Supply pump side: 39.2 to 44.1 Nm {4.0 to 4.5 kgm} Common rail side: 39.2 to 44.1Nm {4.0 to 4.5 kgm} 5) Tighten mounting bolts (3) of the supply pump to the specified torque.

3 Joint bolt of lubricating oil tube (5) (cylinder block side): 9.8 to 12.7 Nm {1.0 to 1.3 kgm} 17)Tighten mounting bolts (21) for bracket (10) to the specified torque. 18)Tighten mounting bolts (22) for bracket (11) to the specified torque.

a When reusing mounting bolts (3), apply liquid adhesive (LT-2) to the bolt threads. 2 Mounting bolt (3): Adhesive (LT-2) 3 Mounting bolt (3): 59 to 74 Nm {6.0 to 7.5 kgm} 6) Tighten the two mounting bolts for bracket (4) on the supply pump side to the specified torque. 3 Supply pump side mounting bolt: 19.6 to 29.4 Nm {2.0 to 3.0 kgm} 7) Tighten mounting bolts (6) and mounting bolts (7) for bracket (7a) to the specified torque in this order. 8) Install fuel spray prevention caps (8) and (9). a When installing the fuel spray prevention caps, turn their slits in the direction shown below. Fuel spray prevention cap (8): cylinder block side Fuel spray prevention cap (9): lower side 9) Install and finger-tighten brackets (10), (11), (12), (13), and (14). 10)Install and finger-tighten clamps (15) and (16). 11)Tighten clamps (15) and (16) to the specified torque. 3 Clamps (15), (16) mounting bolt: 11.8 to 14.7 Nm {1.2 to 1.5 kgm} 12)Tighten mounting bolts (17) of bracket (14) to the specified torque. 13)Tighten mounting bolts (18) of bracket (12) to the specified torque. 14)Tighten mounting bolts (19) of bracket (13) to the specified torque. 15)Tighten bolt (20) to the specified torque. 16)Tighten lubricating oil tube (5) to the specified torque. 3 Joint bolt of lubricating oil tube (5) (supply pump side): 7.9 to 12.7 Nm {0.8 to 1.3 kgm}

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51.Air intake manifold 1) Install the gasket and install air intake manifold (3) loosely. 4 Air intake manifold (3): 30 kg

49.Engine controller cooler 1) Install engine controller cooler (1). 2) Install two fuel hoses (2). 3 Face seal side of fuel hose (2): 84 to 132 Nm {8.5 to 13.5 kgm} 3) Install overflow tube (3). 3 Joint bolt on common rail side: 17.7 to 22.6 Nm {1.8 to 2.3 kgm} 4) Install two wiring harness clamps (4).

50.Engine controller 1) Install engine controller (2). 2) Install ground cable (1).

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2) Tighten the mounting bolts in the following order. 3 Mounting bolt: 59 to 74 Nm {6.0 to 7.5 kgm}

3) Install dipstick pipe (2) and bracket (1). a The shape varies depending on the machine model.

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50 Disassembly and assembly Disassembly and assembly

4) Install all clamps (7) to (10) loosely. 5) Install clamp (11) to bracket (12) loosely, and then tighten clamp (11) to the specified torque. a Clamp (11) is on the back of bracket (12) and used to fix the six fuel high-pressure pipes.

52.Fuel high-pressure pipe between common rail and fuel injector (installation) a If the taper seal portion of the fuel highpressure pipe joint part has any of the following problems, replace the fuel highpressure pipe with a new one since fuel may leak. • There is visible lengthwise slit (b) or spot (c) in range (a) of 2 mm from the end. • Level difference caused by fatigue which is felt with nail in taper seal end part (d) of 2 mm from end.

3 Clamping bolt: 11.8 to 14.7 Nm {1.2 to 1.5 kgm} 6) Tighten bracket (12) to the specified torque. 7) Tighten clamps (7) to (10) to the specified torque. 3 Clamping bolt: 11.8 to 14.7 Nm {1.2 to 1.5 kgm} 8) Install fuel spray prevention caps (13) to both ends of the fuel high-pressure pipe. a Install the fuel spray prevention cap with the slit of the cap on the cylinder head side facing downward and with the slit of the cap on the common rail side facing to the cylinder block.

1) Tighten six fuel high-pressure pipes (1) to the specified torque. a The mounting angle of the inlet connector is adjusted when the fuel injector is installed. 3 Sleeve nut: Supply pump side: 39.2 to 44.1 Nm {4.0 to 4.5 kgm} Common rail side: 39.2 to 44.1 Nm {4.0 to 4.5 kgm} 2) Install the bracket and clamps (2) to (6) loosely, and then tighten the clamps to the specified torque.

53.Fuel spill tube Fit the gaskets to both sides and install spill tube (1).

3 Clamping bolt: 11.8 to 14.7 Nm {1.2 to 1.5 kgm} 3) Tighten the mounting bolts for brackets (2) to (6) to the specified torque. 125E-6 SERIES

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3 Mounting bolt: 9.8 to 12.7 Nm {1.0 to 1.3 kgm}

56.KCCV ventilator 54.Mixing connector 1) Install the gasket. Sling and install mixing connector (2). 4 Mixing connector (2): 35 kg

1) Install KCCV ventilator (5). 2) Install coolant tube (3) and lower drain hose (4). 3) Install two upper hoses (1) and coolant tube (2). a On some machine models, KCCV ventilator (5) may be mounted on the machine side.

2) Install bracket (1). a The shape of bracket (1) varies depending on the machine model.

4) When drain hose (4) is installed, check the following. 55.EGR valve 1) Install EGR valve (2). 2) Install the gasket, and install EGR valve oil drain tube (1a). 3) Install the O-ring, and install oil tube (1b) for the EGR valve hydraulic actuator.

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1] To install check valve (6) in the direction shown in the drawing below. 2] To check that the lower black part (a) of check valve (6) is on the cylinder block side. a The dimension in the figure below shows the parting line between two clolrs. 125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

a At this time, clearance (d) between KVGT housing (13) and seal (12) is as follows. Clearance (d): 3 mm

57.Dosing fuel solenoid valve assembly Install dosing fuel solenoid valve assembly (1). 2) Install seal ring (11) to exhaust connector (10). a Install seal ring (11) with its mark (R) facing the KVGT housing.

a If exhaust connector (10) is removed, install it according to the following procedure. • • • • •

(10): Exhaust connector (11): Seal ring (12): Seal (13): KVGT housing (14): Fuel doser

3) Fix exhaust connector (10) and tool S2 with mounting bolts [1], and install them to KVGT housing (13). a Install exhaust connector (10) in the direction of the arrow. 4) Press in tool S2 until its end reaches flange surface (c) of KVGT housing (13). 5) Fix KVGT housing (13) and tool S2 with mounting bolts [2].

1) By using tool S1, install seal (12) to KVGT housing (13) a Install seal (12) in the direction of the arrow.

a This is to prevent installing exhaust connector (10) in a slanted way. 6) With tool S2 installed, tighten the mounting bolts of exhaust connector (10) to fix it. 7) Check that dimensions (e) and (f) are the following value or less. Dimension (e): 129 mm Dimension (f): 19 mm 8) Remove tool S2.

a Drive in tool S1 until it reaches the flange surface (C) of KVGT housing (13).

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a If fuel doser (2) is removed, clean it according to the following procedure.

Cleaning 1) Remove soot (a) from fuel doser (2) according to the following procedure.

a Tightening torques of the parts related to exhaust connector (10) 3 Plug (15): 2.9 to 5.9 Nm {0.3 to 0.6 kgm} 3 Mounting bolt (16): 44.1 to 53.9 Nm {4.5 to 5.5 kgm} 3 Mounting bolt (17): 68.6 to 73.5 Nm {7.0 to 7.5 kgm}

2) Press cloth [1] with a generous amount of diesel fuel against the soot accumulated at the fuel doser injection port end to let the fuel soak into the soot.

3) After letting fuel soak into the soot, wipe off excessive fuel with cloth [1].

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4) By using brush [2], clean the injection port end to remove the soot. a Clean by using brush [2] and cloth [1] until all of the soot is removed from the injection port. a Use a nylon brush [2] for cleaning. (Do not use a wire brush because it will damage the injection port.) a Use only diesel fuel for cleaning.

Installation 1) Install heat insulator (4) to fuel doser (2). 2) Set mounting bolts (5) to fuel doser (2), install gasket (3), and install them to the exhaust connector. 3 Mounting bolt (5) (width across flats: 8 mm): 8.5 to 9.5 Nm {0.87 to 0.97 kgm} a Use new parts for heat insulators (4), gaskets (3), and mounting bolts (5).

a Install gasket (3) with its stepped part (b) facing toward the exhaust connector.

a Cleaned injection port end A: Cleaning complete (no soot remaining at injection port) B: Cleaning incomplete (soot remaining at injection port)

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58.Fuel filter 1) Install fuel filter and head assembly (5). 2) Install fuel filter head tubes (4), (3), (2), and (1).

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3 Joint bolts of fuel filter head tubes (4), (3), (1): 24.5 to 34.3 Nm {2.5 to 3.5 kgm} 3 Joint bolt of tube (2): 7.8 to 9.8 Nm {0.8 to 1.0 kgm}

59.Fuel pre-filter 1) Install bracket (3). a On some machine models, the fuel prefilter may be mounted on the machine.

2) Install oil filter and head assembly (3) loosely. 3) Install the O-rings, and install two head tubes (2) loosely. 4) After tightening the bolts for the lower flange of head tube (2) to the specified torque, tighten the bolts for the upper flange to the specified torque. 5) Tighten the bolts for the oil filter and head assembly (3) to the specified torque. 6) Install clamp (1). a Face the slit of clamp (1) outward.

2) Install fuel pre-filter and head assembly (2). 3) Install two head tubes (1).

61.Wiring harness assembly 1) Route wiring harness assembly (19) in position, connect the harness connectors to their mating connectors, and then fix it with clamps. 2) Connect the following connectors. (18): ECMJ2 (17): ECMJ1 (16): NE (15): PFUEL a Fix connectors ECMJ1 (17) and ECMJ2 (18) with bolts (20).

60.Oil filter 1) Install lower bracket (5) and upper bracket (4).

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3 Bolt (20) (4 mm): 2.6 to 3.1 Nm {0.27 to 0.32 kgm}

3) Install engine controller cover (14). a The shape of engine controller cover (14) varies depending on the machine model.

4) Connect the following connectors. (3): VGT-REV (Install connector to holder) (2): SVGT (Install connector to holder) (1): PAMB

(6): Fuel injector connectors CN1 to CN6 (on each cylinder head) (5a): SOV1 (5b):SOV2 (4): PDOSER

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(12): EGR-SOL (11): SEGR (10): PO1L (9): G (8): PCV2 (7): PCV1

62.Air vent tube Install the gaskets to both sides and install air vent tube (1). 3 Mounting bolt: 9.8 to 12.7 Nm {1.0 to 1.3 kgm}

63.KVGT and exhaust manifold assembly 1) Install the KVGT and exhaust manifold assembly according to the following procedure. 1] Install rings (19) to manifolds (17) and (18) at both ends.

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2 Both ends (a) of manifolds (17) and (18): Heat-resistant sealant (HOLTS MH705 or equivalent) 2] Install manifolds (17) and (18) to intermediate manifold (16).

3 Mounting bolt (16): 58.8 to 73.5 Nm {6.0 to 7.5 kgm}

a Install them so that dimension (b) at the insertion portion is as follows. Dimension (b) at insertion portion: 5 mm 3] Install the gasket, and install the KVGT to the exhaust manifold. 2 Mounting bolt threads: Seizure prevention compound (LC-G) 3 Mounting bolt: 68.6 to 73.5 Nm {7.0 to 7.5 kgm}

2) Install KVGT coolant tube (14), and then install the clamp. 4] Sling KVGT and exhaust manifold assembly (15), install the gasket, and install them loosely. 4 KVGT and exhaust manifold assembly (15): 65 kg 5] Tighten the mounting bolts at (A), (B), and (C) of the exhaust manifold. 6] Tighten the remaining mounting bolts.

3 Coolant tube (14): Nut on KVGT side: 35 to 65 Nm {3.5 to 6.5 kgm} Joint bolt on cylinder block side: 24.5 to 34.3 Nm {2.5 to 3.5 kgm}

3) Install bracket (13).

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4) Install KVGT lubricating oil tube (12) and install the clamp. 3 Sleeve nut of KVGT lubricating oil tube (12) (cylinder block side):

7) Connect the following connectors. (7): SVGT (8): VGT-REV

24 to 27 Nm {2.4 to 2.7 kgm}

8) Install the following hoses and tubes. 5) Install wiring harness clamp bracket (11) and install three brackets (10).

1] Install two KVGT wiring harnesses (5b) to harness bracket (5c). 2] Install cover (5a). 3] Install coolant tube (5) and fuel hose (6) for fuel doser, and then install the clamps. 3 Fuel hose (6) for fuel doser: 14.7 ± 4.9 Nm {1.5 ± 0.5 kgm} 3 Joint bolt of coolant tube (5): 24.5 to 34.3 Nm {2.5 to 3.5 kgm}

6) Install bracket (9).

9) Install coolant tube (4) and install the clamp. 3 Joint bolt of coolant tube (4): 24.5 to 34.3 Nm {2.5 to 3.5 kgm}

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10)Install bracket (3) and connect connector TWTR (2).

11)Install cover (1) for dosing fuel solenoid valve assembly.

3 Mounting bolt: 59 to 74 Nm {6.0 to 7.5 kgm}

4) Install the gasket and install EGR piping (6) and clamp (6a) loosely, and then tighten the bolts to the specified torque. 5) Install heat insulation plate (5). a The installation of the heat insulation plate (5) depends on the machine model.

64.EGR cooler 1) Install bracket (9).

6) Install two EGR air vent tubes (4). 3 All of joint bolts: 19.6 to 29.4 Nm {2.0 to 3.0 kgm}

2) Install EGR cooler (8). 3) Install the gasket and install EGR piping (7).

7) Install gaskets and O-rings, and then install EGR coolant tubes (3) and (3a). 8) Install air vent tube (2). 3 Joint bolt: 19.6 to 29.4 Nm {2.0 to 3.0 kgm}

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50 Disassembly and assembly Disassembly and assembly

9) Install the gasket, install oil drain tube (1) for KVGT, and then install the clamps.

4) Install tensioner assembly (2) to tensioner bracket (5). 3 Tensioner assembly (2) mounting bolt: 45 to 55 Nm {4.6 to 5.6 kgm}

65.Oil tube for KVGT hydraulic actuator 1) Install the O-rings, install two oil tubes (2) for the KVGT hydraulic actuator, and then install the clamps. 3 Sleeve nut on front cover side: 24 to 27 Nm {2.4 to 2.7 kgm} 3 Joint bolt on KVGT side: 24.5 to 34.3 Nm {2.5 to 3.5 kgm}

5) Install alternator belt (1) according to the following procedure. 1] Set wrench [1] to portion (a) of tension assembly (2) (width across flats: 12.7 mm). 2] Turn wrench [1] anticlockwise when seen from the front of engine, and install alternator belt (1). k Rotate wrench [1] after making sure it

is securely set to portion (a) of tensioner assembly (2). (If you try to rotate the wrench before it is securely attached, it may disengage and cause serious physical injuries due to the strong spring force of tensioner assembly (2).) 2) Connect EPC valve connector VGT-SOL (1).

k After installing alternator belt (1),

return tensioner assembly (2) slowly and carefully. k Take care not to get your fingers

caught between the pulley and alternator belt (1) during work. a Check that alternator belt (1) is fitted correctly in the pulley groove.

66.Alternator assembly 1) Install tensioner bracket (5) to the front cover. 2) Install alternator bracket (6) to the cylinder block. 3) Install alternator assembly (4) to tensioner bracket (5) and alternator bracket (6). 125E-6 SERIES

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50 Disassembly and assembly Disassembly and assembly

a When reinstalling or replacing the sensors, tighten their mounting bolts to the following torque.

67.Starting motor assembly Install starting motor assembly (2) and install mounting bolts (1). a Connect the connector and wiring harness to the specified positions.

Tightening torque Sensor name Ne (Crankshaft) speed 4.9 to 7.9 Nm {0.5 to 0.8 (Hexagonal socket kgm} head bolt) Engine oil pressure 23 ± 3 Nm {2.3 ± 0.3 kgm} Crankcase pressure 2.0 to 2.5 Nm {0.2 to 0.3 (Hexagonal socket kgm} head bolt) Atomosphere pressure 4.1 to 9.5 Nm {0.4 to 1.0 (Hexagonal socket kgm} head bolt) Coolant temperature 23 ± 3 Nm {2.3 ± 0.3 kgm} Charge temperature 23 ± 3 Nm {2.3 ± 0.3 kgm} Engine oil level 11.8 to 14.7 Nm {1.2 to 1.5 (Hexagonal socket kgm} head bolt) 0.98 to 1.27 Nm Air cleaner clogging {0.10 to 0.13 kgm} Charge pressure 23 ± 3 Nm {2.3 ± 0.3 kgm} 70.Check for fuel leakage

68.KDPF bracket Install KDPF bracket (1).

a If supply pump (1), common rail (2), or highpressure fuel pipe (3) or (4) is removed and installed, check for fuel leakage according to the following procedure after assembling the engine.

a The shape of KDPF bracket (1) varies depending on the applicable machine model.

69.Tightening torque of mounting bolts for sensors

50-78

a Clean and degrease the engine and the parts around it in advance so that you may easily find fuel leakage. 1) Spray color checker (developer) over the joint of the supply pump, common rail, fuel injector, and fuel high-pressure pipe. 2) Start the engine, keep its speed at 1,000 rpm or below, and stop it when its speed is stabilized. 3) Check the fuel piping and compornent for fuel leakage.

125E-6 SERIES

50 Disassembly and assembly Disassembly and assembly

a Check the high-pressure fuel circuit parts coated with the color checker (developer) and their peripheries for fuel leakage. a If any fuel leakage is detected, repair it and perform the inspection again from Step 2). 4) Run the engine and keep its speed at low idle. 5) Check the fuel piping and compornent for fuel leakage. a Check the high-pressure fuel circuit parts coated with the color checker (developer) and their peripheries for fuel leakage. a If any fuel leakage is detected, repair it and perform the inspection again from Step 2). 6) Run the engine and keep its speed at high idle. 7) Check the fuel piping and compornent for fuel leakage. a Check the high-pressure fuel circuit parts coated with the color checker (developer) and their peripheries for fuel leakage. a If any fuel leakage is detected, repair it and perform the inspection again from Step 2). 8) Run the engine at high idle and apply a load on the engine. a When checking while the engine is mounted on the machine, stall the torque converter or relieve the hydraulic pump. 9) Check the fuel piping and compornent for fuel leakage. a Check the high-pressure fuel circuit parts coated with the color checker (developer) and their peripheries for fuel leakage. a If any fuel leakage is detected, repair it and perform the inspection again from Step 2). a If no fuel leakage is detected, the inspection is completed. 71.Writing compensation values at replacement of fuel injector and engine controller a When any of the fuel injectors or the engine controller is replaced, write the compensation values into the controller by using INSITE.

125E-6 SERIES

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Removal and installation procedure of supply pump as single component (ENG125-AD70-924-K-00-A) Removal

(ENG125-AD70-520-K-00-A)

1. Wiring harness connector and fuel tube 1) Disconnect the following connectors. (1): PCV1 (2): PCV2 (3): G 2) Disconnect fuel tubes (4) and (5). [*1]

2. Pump piping 1) Disconnect fuel tubes (6) and (7). [*2] 2) Disconnect lubricating oil tube (8). 3) Remove fuel spray prevention cap (9) and loosen the fuel high-pressure pipe clamp. 4) Loosen the sleeve nuts of two fuel high pressure pipes (10). [*3] a Loosen the sleeve nuts on the common rail side, as well.

4. Supply pump drive gear 1) Remove cover (19). [*5] 2) Rotate the crankshaft in the normal direction (counterclockwise when seen from the flywheel side), and match the center point (a) between stamp lines 2/5TOP and 3/4TOP on damper (20) to pointer (21). (At this time, stamp line 1/6TOP is almost at the bottom.) a At this time, check that the forcing tap of the drive gear is aligned with the mounting bolt hole of cover (19). (If not, rotate the crankshaft one more turn.) a In this position, the key of the supply pump shaft is rotated clockwise by 15 ° from the top.

3. KCCV ventilator 1) Disconnect two upper hoses (11), two coolant tubes (12), and lower drain hose (13). [*4] 2) Remove KCCV ventilator (13a). 3) Disconnect fuel filter head tubes (14), (15), (16), and (17). 4) Remove fuel filter and head assembly (18).

3) Remove mounting nut (22).[*6]

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50 Disassembly and assembly Disassembly and assembly

4) Install tools P1, P2, and P3 and tighten the center bolt of P1 to pull out the supply pump drive gear from the shaft. a Keep tools P1, P2, and P3 installed to prevent the supply pump drive gear from coming off.

[*1] 3 Joint bolt of fuel tubes (4) and (5): 14.8 to 19.6 Nm {1.5 to 2.0 kgm} 3 Joint bolt: 7.9 to 12.7 Nm {0.8 to 1.3 kgm} [*2] 3 Joint bolt of fuel tubes (6) and (7) (supply pump side): 14.8 to 19.6 Nm {1.5 to 2.0 kgm} [*3] 1. Check of fuel high-pressure pipe joint part a If the taper seal portion of the fuel highpressure pipe joint part has any of the following problems, replace the fuel highpressure pipe with a new one since fuel may leak. • There is visible lengthwise slit (b) or spot (c) in range (a) of 2 mm from the end. • There is level difference caused by fatigue which is felt with nail in taper seal end part (d) of 2 mm from end.

5. Supply pump assembly 1) Remove bracket (23) and loosen the mounting bolts for bracket (24). 2) Remove four mounting bolts (25), and then remove supply pump assembly (26). [*7] a Keep tools P1, P2, and P3 installed to prevent the supply pump drive gear from coming off.

[*4] • When drain hose (13) is installed, check the following. 1. Check valve (13a) is installed in the direction shown in the drawing below. 2. The lower black part (a) of check valve (13a) faces to the cylinder block. a The dimension in the figure below shows the parting line between two clolrs.

Installation

(ENG125-AD70-720-K-00-A)

a Perform installation in the reverse order to removal. 125E-6 SERIES

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3 Mounting nut (22): 176 to 196 Nm {18 to 20 kgm}

[*5] 3 Mounting bolt of cover (19): 98 to 123 Nm {10.0 to 12.5 kgm} [*6] 1. Set key (22a) of the supply pump shaft nearly at the top. 2. Align key slot (a) of supply pump drive gear (30) with key (22a) of the shaft. 3. At the same time, match timing mark (C) on fuel supply pump drive gear (30) to that on cam gear (31), and then tighten mounting nut (22).

[*7] a Install the supply pump according to the following procedure. 1. Finger-tighten four supply pump mounting bolts (25). a When reusing mounting bolts (25), apply liquid adhesive (LT-2) to the bolt threads.

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50 Disassembly and assembly Disassembly and assembly

2 Mounting bolt (25): Adhesive (LT-2) 2. Install and finger-tighten the mounting bolts for brackets (23) and (24).

3 Supply pump side mounting bolt: 19.6 to 29.4 Nm {2.0 to 3.0 kgm} 9. Tighten mounting bolts (33) and mounting bolts (34) for bracket (24) to the specified torque in this order. 10.Install fuel spray prevention caps (35) and (36). a When installing the fuel spray prevention caps, face their slits in the direction shown below. Fuel spray prevention cap (35): cylinder block side Fuel spray prevention cap (36): lower side 11.Install and finger-tighten the mounting bolts for brackets (37), (38), (39), (40), and (41). 12.Install and finger-tighten the bolts of clamps (42) and (43). 13.Tighten the bolts of clamps (42) and (43) to the specified torque. 3 Clamps (42), (43) mounting bolt:

3. Install and finger-tighten mounting sleeve nuts of high-pressure fuel pipes (30) and (31). 4. Install and finger-tighten the bolts of clamps and mounting bolts for brackets for the above-mentioned high-pressure fuel pipes (30) and (31). 5. Install and finger-tighten the mounting sleeves for lubrication oil tube (32). 6. Tighten the sleeve nuts of high-pressure fuel pipes (30) and (31) to the specified torque. 3 Sleeve nut: Supply pump side: 39.2 to 44.1 Nm {4.0 to 4.5 kgm} Common rail side: 39.2 to 44.1 Nm {4.0 to 4.5 kgm} 7. Tighten mounting bolts (25) for the supply pump to the specified torque.

11.8 to 14.7 Nm {1.2 to 1.5 kgm} 14.Tighten mounting bolts (44) for bracket (41) to the specified torque. 15.Tighten mounting bolts (45) for bracket (39) to the specified torque. 16.Tighten mounting bolts (46) for bracket (40) to the specified torque. 17.Tighten mounting bolts (47) to the specified torque. 18.Tighten sleeve nuts for lubricating oil tube (32) to the specified torque. 3 Lubricating oil tube (32) joint bolt (supply pump side): 7.9 to 12.7 Nm {0.8 to 1.3 kgm} 3 Joint bolt of lubricating oil tube (32) (cylinder block side): 9.8 to 12.7 Nm {1.0 to 1.3 kgm} 19.Tighten mounting bolts (48) for bracket (37) to the specified torque. 20.Tighten mounting bolts (49) for bracket (38) to the specified torque.

3 Mounting bolt (25): 59 to 74 Nm {6.0 to 7.5 kgm} 8. Tighten the two mounting bolts for bracket (23) on the supply pump side to the specified torque.

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a Check the high-pressure circuit parts coated with the color checker (developer) and their peripheries for fuel leakage. a If any fuel leakage is detected, repair it and perform the inspection again from Step 2). 4. Start the engine and keep its speed at low idle. 5. Check the fuel piping and compornent for fuel leakage. a Check the high-pressure circuit parts coated with the color checker (developer) and their peripheries for fuel leakage. a If any fuel leakage is detected, repair it and perform the inspection again from Step 2). 6. Start the engine and keep its speed at high idle. 7. Check the fuel piping and compornent for fuel leakage. a Check the high-pressure circuit parts coated with the color checker (developer) and their peripheries for fuel leakage. Check for fuel leakage a If supply pump (27), common rail (28), or highpressure fuel pipe (29) or (30) is removed and installed, check for fuel leakage according to the following procedure after assembling the engine.

a If any fuel leakage is detected, repair it and perform the inspection again from Step 2). 8. Start the engine and apply a load on the engine at its full speed. a When checking while the engine is mounted on the machine, stall the torque converter or relieve the hydraulic pump pressure. 9. Check the fuel piping and compornent for fuel leakage. a Check the high-pressure circuit parts coated with the color checker (developer) and their peripheries for fuel leakage. a If any fuel leakage is detected, repair it and perform inspection again from Step 2).

a Clean and degrease the engine and the parts around it in advance so that you may easily find fuel leakage. 1. Spray color checker (developer) over the joint of the supply pump, common rail, fuel injector, and fuel high-pressure pipe. 2. Start the engine, keep its speed at 1,000 rpm or below, and stop it when its speed is stabilized. 3. Check the fuel piping and compornent for fuel leakage.

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a If no fuel leakage is detected, inspection is completed.

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50 Disassembly and assembly Disassembly and assembly

Engine front oil seal replacement procedure Removal

(ENG125-A350-520-K-00-A)

1. Alternator belt [*1]

(ENG125-A350-924-K-00-A)

4 Damper and pulley assembly (6): 25 kg

1) Set wrench [1] to portion (a) of tensioner assembly (5) (width across flats: 12.7 mm). 2) Turn wrench [1] counterclockwise when seen from the front of engine, and remove alternator belt (4). k Rotate wrench [1] after making sure it is

securely set to portion (a) of tensioner assembly (5). (If you try to rotate the wrench before it is securely attached, it may disengage and cause serious physical injuries due to the strong spring force of tensioner assembly (5).) 3. Engine front seal [*3] k After removing alternator belt (4), return

tensioner assembly (5) slowly and carefully. k Take care not to get your fingers caught

between the pulley and alternator belt (4) during work.

a Before removing engine front seal (2), drive it in a little to separate. a Take care not to damage the oil seal contact faces of front cover (1) and crankshaft (3). a If it is difficult to remove engine front seal (2), remove it according to the following procedure. 1) Drill several holes with aproximately 3 mm in diameter into engine front seal (2). a Remove all the chips. 2) Replace the tip of tool L with the drill-type tip and insert it in one of the holes drilled in the above step. 3) Pull slide hammer [SH] of tool L toward you to remove engine front seal (2) with the impact.

2. Damper and pulley assembly [*2]

a Perform the above procedure at several places so that engine front seal (2) does not slant.

1) Using lifting tool [2], sling damper and pulley assembly (6). 2) Remove six mounting bolts. 3) Using guide bolt [3], pull out and lift off damper and pulley assembly (6).

• Tool L

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50 Disassembly and assembly Disassembly and assembly

a There are two types in the mounting bolts of damper and pulley assembly (6). 3 Mounting bolt (22 mm width across flats, one pc.): 157 to 196 Nm {16 to 20 kgm} 3 Mounting bolt (24 mm width across flats, five pcs.): 245 to 309 Nm {25.0 to 31.5 kgm} [*3] a Install engine front seal (2) according to the following procedure.

Installation

(ENG125-A350-720-K-00-A)

a Perform installation in the reverse order to removal. [*1] a Install alternator belt (4) according to the following procedure. 1. Set wrench [1] to portion (a) of tension assembly (5) (width across flats: 12.7 mm). 2. Turn wrench [1] counterclockwise when seen from the front of engine, and install alternator belt (4). k Rotate wrench [1] after making sure it is

a Check that crankshaft end surface corners, sliding surfaces of oil seal lip, and front cover are free from flaws, burrs, rust, etc. 1. Set engine front seal (2) to front cover (1) and press-fit it with a plastic hammer until oil seal lip (a) fits on crankshaft (3). a Take care not to install engine front seal (2) in a wrong direction. a When press-fitting engine front seal (2), hit its periphery evenly so that it does not be deformed. a Take care that oil seal lip (a) is not caught in crankshaft (3). 2 Engine front seal (2) (50 to 80% full of hollow part of lip): Grease (G2-LI)

k After installing alternator belt (4), return

tensioner assembly (5) slowly and carefully. k Take care not to get your fingers caught

between the pulley and alternator belt (4) during work. a Check that alternator belt (4) is fitted correctly in the pulley groove.

[*2]

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50 Disassembly and assembly Disassembly and assembly

2. Install tool M1 and tighten three tools M2 (bolts) evenly until they reach the end to press fit engine front seal (2) to front cover (1). a Do not fit tools M3 (washers) to tools M2 (bolts). 3. Remove three tools M2 (bolts) and fit three each of tools M3 (washers) to tools M2 (bolts). 4. Install three tools M2 (bolts) again and tighten them until the end of tool M1 reaches the end of front cover (1) to press fit engine front seal (2). a Press fitting distance (b) of engine front seal (2) from end of front cover (1): 16 (+1/0) mm

a Press fitting distance (c) of engine front seal (2) from end of crankshaft (3): 9.2 (+1/0) mm

125E-6 SERIES

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50 Disassembly and assembly Disassembly and assembly

Engine rear oil seal replacement procedure Removal

(ENG125-A510-520-K-00-A)

1. KDPF bracket Remove KDPF bracket (1). a The shape of KDPF bracket (1) depends on the applicable machine model.

(ENG125-A510-924-K-00-A)

2] Replace the tip of tool L with the drill-type tip and insert it in one of the holes drilled in the above step. 3] Pull slide hammer [SH] of tool L toward you to remove engine rear seal (2) with the impact. a Perform the above procedure at several places so that engine rear seal (2) does not slant.

2. Flywheel[*1] 1) By using eyebolt [1], sling flywheel (7). 2) Remove six mounting bolts and pull out the dowel pin. 3) By using guide bolt [2], pull out and lift off flywheel (7).

• Tool L

4 Flywheel (7): 50 kg

2) Removal of sleeved oil seal

3. Engine rear seal [*2] a Before removing engine rear seal (2), drive in it a little to separate. a Take care not to damage the oil seal contact faces of flywheel housing (3) and crankshaft (4). a If it is difficult to remove engine rear seal (2), remove it according to the following procedure. 1) Removal of standard oil seal

1] Replace the tip of tool L with the hooktype tip and hitch it to outer case (a) of engine rear seal (2). 2] Pull slide hammer [SH] of tool L toward you to remove engine rear seal (2) with the impact. a Perform the above procedure at several places so that engine rear seal (2) does not slant. 3] Cut and remove sleeve (5) with a chisel and a hammer. a Take care not to damage crankshaft (4).

1] Drill several holes with approximately 3 mm in diameter into engine rear seal (2). a Remove all the chips.

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a Remove all the chips.

Installation

a Impact wrench can be used 2nd time: 289.1 ± 19.6 Nm {29.5 ± 2.0 kgm}

(ENG125-A510-720-K-00-A)

a Perform installation in the reverse order to removal. [*1] a Install flywheel (1) according to the following procedure. 1. By using eyebolt [1], sling flywheel (1). By using guide bolt [2], install the flywheel while matching the dowel pin. 4 Flywheel (1): 50 kg 2 Threaded portion of mounting bolt and seating surface: Engine oil (SAE30-DH or equivalent) 2. Tighten the mounting bolts in the following order.

3. By using dial gauge [3], measure the facial runout and radial runout. a Facial runout: Max. 0.20 mm

3 Mounting bolt: 1st time: 147 ± 19.6 Nm {15 ± 2.0 kgm}

125E-6 SERIES

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50 Disassembly and assembly Disassembly and assembly

a Radial runout: Max. 0.15 mm

a The left one in the following figure shows the standard oil seal and the right one shows the sleeved oil seal.

2. Installation of standard oil seal a Clean, degrease, and dry the contacting surface against the flywheel housing. a Before installing the oil seal, check that the end corners of crankshaft (4), oil seal lip sliding surfaces, and housing are free from a flaw, burr, fin, rust, etc.

[*2] a Install engine rear seal (2) according to the following procedure. 1. Selection of oil seal a Check the wear of the crankshaft and select the type of the Teflon seal (laydown lip seal) to install, "standard oil seal" or "sleeved oil seal", depending on the wear of the crankshaft.

a When installing the engine rear seal, do not apply oil or grease to the hatched portions of the crankshaft and oil seal lip (b). Thoroughly wipe off oil and grease from the crankshaft. a Spare standard engine rear seal (2) has installation guide (6). Never remove this guide before installing the engine rear seal.

1) Put large inside diameter side (c) of installation guide (6) of engine rear seal (2) to the end of crankshaft (4).

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a Take care not to install engine rear seal (2) in a wrong direction.

2) Push in the outer case end face of engine rear seal (2) evenly. 3) Push in to a degree that engine rear seal (2) does not come off the housing, and remove installation guide (6). a When removing installation guide (6), take care not to scratch the oil seal lip.

a After press-fitting engine rear seal (2), remove the red sealant layer from its periphery.

3. Installation of sleeved oil seal a Clean, degrease, and dry the contacting surface against the flywheel housing. a Check that crankshaft end surface corners, sliding surfaces of oil seal lip, and housing are free from flaws, burrs, rust, etc. a Do not apply oil or grease to the hatched parts of the crankshaft, inner cylinder of sleeve (5), and engine rear seal lip (b). Thoroughly wipe off oil and grease from the crankshaft. a Handle the engine rear seal and sleeve (5) as an assembly and never separate them from each other.

4) Install tool N1 and tighten three tools N2 (bolts) evenly until they reach the end to press-fit engine rear seal (2). a Do not fit tools N3 (washers) to tools N2 (bolts). a When press-fitting the engine rear seal, take care not to scratch the oil seal lip with a tool etc. 5) Remove tools N2 (bolts) and fit one each of tools N3 (washers) to tools N2 (bolts). 6) Install three tools N2 (bolts) to tool N1 again and tighten them until the end of tool N1 reaches the end of crankshaft (4) to press-fit engine rear seal (2).

1) Set sleeve and engine rear seal assembly (2) to tool N4.

a Press-fitting distance (d) of engine rear seal (2) from end of crankshaft (4): 16.3 ± 0.2 mm a When press-fitting engine rear seal (2), take care not to scratch the oil seal lip with a tool etc. 125E-6 SERIES

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2 Sleeve inner cylinder surface: Liquid gasket (LG-7)

a After press-fitting sleeve and engine rear seal assembly (2), remove the red sealant layer from its periphery.

2) Put sleeve (5) of sleeve and engine rear seal assembly (2) to the end face of crankshaft (4) and evenly tighten three tools N5 (bolts) of tool N4 to press-fit sleeve and engine rear seal assembly (2). a Install one each of tools N6 (washers) to tools N5 (bolt) and tighten tools N5 (bolts) until they reach the end.

3) Replace tool N4 with tool N7 and tighten three tools N8 (bolts) evenly until they reach the end to press-fit sleeve and engine rear seal assembly (2). a Do not fit tools N9 (washers) to tools N8 (bolts). 4) Remove tools N8 (bolts) and fit three each of tools N9 (washers) to tools N8 (bolts). 5) Install three tools N8 (bolts) to tool N7 again and tighten them until the end of tool N7 reaches the end of crankshaft (4) to press-fit sleeve and engine rear seal assembly (2). a Press-fitting distance (e) of sleeve and engine rear seal assembly (2) from end of crankshaft (4): 16.3 ± 0.2 mm a When press-fitting engine rear seal (2), take care not to scratch the oil seal lip with a tool, etc.

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SHOP MANUAL

ENGINE 125E-6 SERIES Model

Serial Number

125E-6 SERIES

60 Maintenance standard 6 60 Maintenance standard

125E-6 SERIES

60-1

60 Maintenance standard Table of contents

Table of contents (ALL-0310-002-A-00-A) 60 Maintenance standard................................................................................................................... 60-1 Table of contents ........................................................................................................................ 60-2 Intake and exhaust system parts .................................................................................................. 60-3 KVGT.................................................................................................................................. 60-3 Engine main body parts............................................................................................................... 60-4 Cylinder head ...................................................................................................................... 60-4 Cylinder block ...................................................................................................................... 60-5 Cylinder liner ....................................................................................................................... 60-7 Crankshaft........................................................................................................................... 60-8 Cam follower and push rod ................................................................................................... 60-9 Piston ............................................................................................................................... 60-11 Connecting rod .................................................................................................................. 60-13 Vibration damper................................................................................................................ 60-15 Timing gear ....................................................................................................................... 60-16 Camshaft .......................................................................................................................... 60-17 Valve and valve guide......................................................................................................... 60-18 Rocker arm........................................................................................................................ 60-20 Crosshead and guide ......................................................................................................... 60-21 Flywheel............................................................................................................................ 60-22 Lubrication system.................................................................................................................... 60-24 Main relief valve ................................................................................................................. 60-24 Safety valve....................................................................................................................... 60-25 Cooling system......................................................................................................................... 60-26 Oil cooler........................................................................................................................... 60-26 Water pump....................................................................................................................... 60-27 Thermostat ........................................................................................................................ 60-28

60-2

125E-6 SERIES

60 Maintenance standard KVGT

Intake and exhaust system parts (ENG107-A900-001-K-00-A) KVGT

(ENG125-AA10-034-K-00-A)

KVGT: Abbreviation for KOMATSU Variable Geometry Turbocharger

No.

Item

Radial play (Play in radial 1 direction)

Criteria Use light finger pressure to push the compressor wheel towards the side of the compressor housing. Repeat the procedure for the turbine wheel and housing. Either wheel shall not contact the housing.

End play (play in axial 2 direction)

0.47 to 0.67

Check of KVGT opration 3 (Check of nozzle ring operation)

If values of KDOC inlet temperature: approximately 250 °C or below and KVGT solenoid current: approximately 1000 mA remain unchanged after performing regeneration for service, KVGT is defective. (Since the time required for manual stationary regeneration depends on the accumulated soot level, see failure code CA2639 )

125E-6 SERIES

Unit: mm Remedy

Replace KVGT as an assembly (including hydraulic actuator, KVGT position sensor)

60-3

60 Maintenance standard Cylinder head

Engine main body parts (ENG107-R402-001-K-00-A) Cylinder head

(ENG125-A100-034-K-00-A)

a Order of tightening cylinder head mounting bolts a Tighten the cylinder head mounting bolts in the order of (1) to (7). No.

Item

Criteria

Distortion of mounting 1 surface to cylinder block 2 Protrusion of nozzle

Tolerance

Repair limit

0 to 0.06

0.09

Engine SAA6D125E-6 Bolt

Procedure 1st stage

Tightening torque of cylinder head mounting bolt 3 (apply molybdenum disulfide or engine oil to underside of bolt head.)

(1) – (6)

2nd stage 3rd stage

(7) Tightening torque of injector 4 mounting bolt Tightening torque of rocker 5 arm housing mounting bolt

60-4

–

Target (Nm {kgm}) 66 {6.75} 66 {6.75}

Unit: mm Remedy Repair by grinding or replace cylinder head Replace nozzle sleeve

Standard 3.20 to 3.90 Target (Nm Range (Nm {kgm}) {kgm}) 88.2 to 107.8 98 {10} {9 to 11} 166.6 to Tighten in order 176.4 176.4 {18} shown in above {17 to 18} figure Retighten by 90 to 120 deg. 120 deg. 58.8 to 73.5 68.6 {7} {6 to 7.5} Range (Nm {kgm}) 58.8 to 73.5 {6.0 to 7.5} Tighten 58.8 to 73.5 {6.0 to 7.5}

125E-6 SERIES

60 Maintenance standard Cylinder block

Cylinder block

No.

(ENG125-A300-034-K-00-A)

Item

Distortion of mounting 1 surface to cylinder head Inside diameter of main metal mounting hole

Criteria Tolerance

Repair limit

0 to 0.080

0.12

Standard dimension

Tolerance +0.015 -0.010

116

2 Roundness of mounting hole

Inside diameter of cam 4 bushing mounting hole Inside diameter of cam 5 bushing

125E-6 SERIES

Replace main metal cap

Repair limit: 0.005

Thickness of main metal Inside diameter of main 3 metal

Unit: mm Remedy Repair by grinding or replace cylinder block

-0.005 -0.020

3 Standard dimension

Tolerance

Repair limit

110

+0.040 +0.010

110.15

Standard dimension

Tolerance +0.030 0

63 Standard dimension

Tolerance

Repair limit

+0.070 0

60.30

Replace metal

Replace main metal Correct or replace cylinder block Replace cam bushing

60-5

60 Maintenance standard Cylinder block

No.

Item

1st stage

Criteria Target (Nm {kgm}) 98 {10}

2nd stage

196 {20}

3rd stage

Retighten by 90 deg.

–

54 {5.5}

M16 (5 pieces)

274 {28}

M14 (1 piece)

176 {18}

Procedure Tightening torque of main 6 cap bolt (apply engine oil to threads)

Tightening torque of oil pan 7 mounting bolt Tightening torque of 8 crankshaft pulley mounting bolt Level difference between underside surfaces of 9 cylinder block and flywheel housing Level difference between 10 under surfaces of cylinder block and front cover

60-6

Unit: mm Remedy Range (Nm {kgm}) 88 to 108 {9 to 11} 191 to 201 {19.5 to 20.5} Retighten by 90 Tighten (+30/0) deg. 34 to 73 {3.5 to 7.5} 245 to 309 {25 to 31.5} 157 to 196 {16 to 20}

Repair limit: 0.35 Correct by reassembling Repair limit: 0.28

125E-6 SERIES

60 Maintenance standard Cylinder liner

Cylinder liner

No.

(ENG125-A340-034-K-00-A)

Item

Criteria

1 Protrusion of cylinder liner

Inside diameter of cylinder liner (unit) 2 Roundness of inside of cylinder liner (unit) Cylindricity of inside of cylinder liner (unit) Outside diameter of cylinder liner (counterbore portion) (unit) 3 Interference of cylinder liner and block (counterbore portion) Outside diameter of cylinder liner (bottom of counterbore) 4 Interference of cylinder liner and block (bottom of counterbore) Outside diameter of cylinder liner (O-ring portion) 5 Clearance between cylinder liner and block (O-ring portion)

125E-6 SERIES

Unit: mm Remedy Replace cylinder liner or cylinder

Repair limit: 0.07 to 0.15 Rank

Standard dimension

125

Tolerance

Repair limit

+0.020 0 +0.040 +0.021

125.20 125.20

Repair limit: 0.08 Repair limit: 0.08 Standard dimension

Tolerance

153

±0.025

Standard clearance: 0 to 0.113 Standard dimension

Replace cylinder liner (spare liner is supplied only for rank B)

Replace cylinder liner or block

Standard interference

Tolerance +0.090 +0.040 Allowable interference

0.01 to 0.12

0.01

Standard dimension

Tolerance +0.386 +0.361

Replace cylinder liner

Standard clearance: 0.014 to 0.079

Replace cylinder liner or block

145

141

Replace cylinder liner Replace cylinder liner or block

60-7

60 Maintenance standard Crankshaft

Crankshaft

No.

(ENG125-A530-034-K-00-A)

Item

1 End play

Outside diameter of main journal 2 Roundness of main journal Clearance of main journal

Outside diameter of crankpin journal 3 Roundness of crankpin journal Clearance of crankpin journal 4 Bend of crankshaft

60-8

Criteria Standard value

Repair limit

0.140 to 0.32

0.50

Standard dimension S.T.D. 110 0.25U.S. 109.75 0.50U.S. 109.50 0.75U.S. 109.25 1.00U.S. 109.00 Standard 0 to 0.010 Standard clearance 0.062 to 0.106 Standard dimension S.T.D. 80 0.25U.S. 79.75 0.50U.S. 79.50 0.75U.S. 79.25 1.00U.S. 79.00 Standard 0 to 0.010 Standard clearance

Repair limit 109.88 109.63 -0.050 109.38 -0.070 109.13 108.88 Repair limit 0.020 Allowable clearance 0.27 Repair limit Tolerance 79.88 79.63 -0.050 79.38 -0.070 79.13 78.88 Repair limit 0.020 Allowable clearance

Unit: mm Remedy Replace thrust metal or correct with oversize parts

Tolerance

0.046 to 0.090

0.24

Standard

Repair limit

0 to 0.09

0.20

Correct with undersize parts or replace journal

Replace main metal

Correct with undersize parts or replace journal

Replace connecting rod metal Correct with undersize parts or replace crankshaft

125E-6 SERIES

60 Maintenance standard Cam follower and push rod

Cam follower and push rod

125E-6 SERIES

(ENG125-A710-034-K-00-A)

60-9

60 Maintenance standard Cam follower and push rod

No.

Item Outside diameter of cam follower shaft

Inside diameter of cam follower shaft hole Outside diameter of cam 2 roller 3

Unit: mm Remedy

Criteria Standard dimension

Tolerance -0.040 -0.050 +0.020 0 +0.250 +0.280 -0.262 -0.287 -0.364 -0.376

19.8 19.8 32

Inside diameter of cam roller

Outside diameter of cam roller pin

Repair limit 19.73 – 31.70 12.78

Replace

12.62

Standard dimension 4 Radius of push rod ball end Radius of push rod socket end 6 Bend of push rod Tightening torque of cam – follower shaft mounting bolt 5

60-10

Tolerance 0 12.7 -0.20 0 12.7 -0.20 Repair limit: 0.50 (overall swing of indicator) 51 ± 7.4 Nm {5.25 ± 0.75 kgm}

Tighten

125E-6 SERIES

60 Maintenance standard Piston

Piston

(ENG125-A580-034-K-00-A)

125E-6 SERIES

60-11

60 Maintenance standard Piston

No.

Item Rank

Outside diameter of piston

A or S B or L No.

Criteria Standard Tolerance dimension -0.090 125 -0.105 -0.075 125 -0.090 Measuring Standard point dimension

No.1 ring

No.2 ring

Oil ring

No.1 ring

No.2 ring

Oil ring

Thickness of piston ring

2–4

Width of piston ring groove

No. Clearance between piston ring and piston ring groove

2 3

Measuring point No.1 ring No.2 ring

Outside diameter of piston pin 5

–

Inside diameter of piston pin hole Clearance between piston pin and piston Weight of piston

Repair limit 124.80 124.80

Replace piston (spare piston is supplied only for rank A or S)

Tolerance

-0.005 Replace piston -0.025 ring -0.010 2.4 -0.030 -0.010 4 -0.030 *1 Check with groove wear gauge (Clearance with new ring Replace piston installed: 0.15) +0.040 3 +0.020 Allowable Standard clearance clearance Check with groove wear Replace piston or piston ring gauge 2.42

0.030 to 0.15 0.070 No.1 ring 0.37 to 0.47 2.0 2 No.2 ring 3 1.10 to 1.20 2.0 Oil ring 4 0.23 to 0.35 1.0 Standard dimension Tolerance 0 48 -0.006 +0.045 48 +0.035 Standard clearance Allowable clearance 0.035 to 0.051 0.063 2,986 g, Allowable range: ±60 g 4

Closed gap of piston ring

Unit: mm Remedy

Oil ring

Replace piston ring or cylinder liner Replace piston pin Replace piston Replace piston or piston pin Replace piston

a *1: Part No. of groove wear gauge: 795-901-1130

60-12

125E-6 SERIES

60 Maintenance standard Connecting rod

Connecting rod

No.

(ENG125-A590-034-K-00-A)

Item Inside diameter of connecting rod small end bushing

Clearance between connecting rod small end bushing and piston pin Inside diameter of 2 connecting rod small end bushing mounting hole Inside diameter of connecting rod large end 3 metal (crankpin journal)

Criteria Standard dimension

Tolerance

Repair limit

+0.041 +0.025

48.08

Standard clearance

Allowable clearance

0.025 to 0.047

0.10

Standard dimension

Tolerance +0.030 0

53 Standard dimension

Tolerance

Unit: mm Remedy Replace bushing (spare part is semi-finished part) Replace bushing or piston pin Replace connecting rod

Repair limit

Replace metal +0.020 80.12 -0.010 +0.022 – 85 Diameter of connecting rod Replace -0.004 large end metal mounting Tighten connecting rod cap with specified torque and connecting rod 4 hole measure +0.005 Thickness of connecting rod Replace metal – 2.5 bearing metal -0.004 Repair limit Item Standard Parallelism a 0 to 0.20 0.25 Replace Parallelism and torsion of 5 connecting rod connecting rod Torsion b 0 to 0.30 0.35 – Dimension c 240 Range (Nm Tightening torque of Target (Nm {kgm}) Procedure {kgm}) connecting rod cap mounting bolts 93 to 103 {9.5 to 1st stage 98 {10} Tighten 6 10.5} (apply engine oil to bolt threads and nut seat Retighten by 90 Retighten by 90 2nd stage surface.) deg. (+30/0) deg. Allowable range: Dispersion of weight of connecting rods Replace – Weight of connecting rod in 1 engine must not exceed 140 g. 125E-6 SERIES

60-13

60 Maintenance standard Connecting rod

a Do not use a connecting rod cap mounting bolt more than 5 times. Each time the bolt is used, make a punch mark on its head.

60-14

125E-6 SERIES

60 Maintenance standard Vibration damper

Vibration damper

(ENG125-A5E0-034-K-00-A)

No. Item 1 Visual check Tightening torque of 2 vibration damper mounting bolt

125E-6 SERIES

Unit: mm Remedy Criteria Rubber parts must be free from cracking and flaking. Replace Range (Nm Target (Nm {kgm}) Bolt {kgm}) Tighten 98 to 213 {10 to 111 {11.3} M12 12.5}

60-15

60 Maintenance standard Timing gear

Timing gear

No.

(ENG125-A5A0-034-K-00-A)

Item Position

2 3 4

Measuring point

Crank gear and main idler gear (large) Main idler gear (small) and B camshaft gear camshaft gear and fuel Backlash of each gear C supply pump gear Main idler gear (large) and a water pump gear Main idler gear (large) and b oil pump idler gear Oil pump idler gear and oil c pump drive gear Tolerance Standard dimension Clearance between main Shaft Hole idler gear bushing and shaft +0.014 +0.063 47.6 +0.001 +0.039 -0.025 +0.065 Clearance between oil pump 35 idler gear bushing and shaft -0.041 0 Standard End play of main idler gear 0.05 to 0.17 End play of oil pump idler 0.05 to 0.21 gear A

–

60-16

Unit: mm Remedy

Criteria Standard

Repair limit

0.116 to 0.359 0.105 to 0.325 0.105 to Replace 0.325 0.6 0.076 to 0.366 0.105 to 0.337 0.082 to 0.389 Standard Allowable clearance clearance Replace 0.025 to 0.20 bushing 0.062 0.025 to 0.20 0.106 Repair limit Replace thrust 0.4 bearing 0.4

125E-6 SERIES

60 Maintenance standard Camshaft

Camshaft

No.

(ENG125-A5G0-034-K-00-A)

Item

1 End play

Outside diameter of camshaft journal Clearance of camshaft journal

3 Bend of camshaft 4 Height of camshaft lobe

125E-6 SERIES

Criteria Repair limit 0.50 Tolerance -0.080 60 -0.110 Standard clearance Allowable clearance 0.080 to 0.180 0.28 Repair limit: 0.03 (Total deflection of indicator) Standard Repair limit Tolerance dimension +0.395 52 51.73 +0.195

Standard 0.15 to 0.35 Standard dimension

Unit: mm Remedy Replace thrust plate Replace Replace cam bushing

Replace

60-17

60 Maintenance standard Valve and valve guide

Valve and valve guide

60-18

(ENG125-A700-034-K-00-A)

125E-6 SERIES

60 Maintenance standard Valve and valve guide

No.

Unit: mm Remedy Criteria Standard Repair limit Valve Tolerance dimension Replace valve Depression of valve Intake valve 1.88 ±0.10 2.51 or valve seat Exhaust 1.20 ±0.10 1.90 valve Standard Repair limit Valve dimension Replace valve Thickness of valve lip Intake valve 2.10 1.7 Exhaust valve 1.50 1.2 Intake valve Exhaust valve Correct or Valve seat angle replace valve or Standard 30 deg. ± 15´ 45 deg. ± 15´ valve seat Standard Valve Tolerance dimension -0.045 Outside diameter of valve Intake valve 9 Replace valve stem -0.065 -0.050 Exhaust valve 9 -0.070 Intake, +0.015 Before head 9 is press fitted exhaust -0.003 Replace valve Inside diameter of valve valves guide guide Intake, +0.009 After head is exhaust 9 press fitted -0.011 valves Allowable Standard Valve clearance clearance Replace valve Clearance between valve or valve guide guide and stem Intake valve 0.034 to 0.074 0.22 Exhaust valve 0.039 to 0.079 0.24 Repair limit: 0.01 (Total deflection of indicator in 100 mm) Replace Bend of valve stem Standard Tolerance Driving height of valve guide Correct 20 ±0.2 Color Standard Repair limit Valve Code dimension Free length of valve spring Light blue – Intake 76.2 Light blue – Exhaust 76.2 Standard Allowable Installed Color load load Valve length Code (N {kg}) (N {kg}) Replace valve 519.8 ± 26 spring Load at installed length of 468 {47.7} Intake Light blue 56.0 {53.0 ± valve spring 2.7} 519.8 ± 26 ExLight blue 468 {47.7} 56.0 {53.0 ± haust 2.7} Perpendicularity of valve Allowable limit: 2 deg. (both ends) spring

125E-6 SERIES

Item

60-19

60 Maintenance standard Rocker arm

Rocker arm

No.

(ENG125-A770-034-K-00-A)

Item

Clearance between rocker arm shaft and rocker arm

Standard clearance

Tolerance -0.053 -0.066 +0.033 -0.027 Allowable clearance

0.026 to 0.099

0.13

Bend of rocker arm shaft

Repair limit: 0.20 (Total deflection of indicator)

Outside diameter of rocker arm shaft Diameter of rocker arm shaft 1 hole

Tightening torque of locknut 2 of rocker arm adjustment screw 3

Unit: mm Remedy

Criteria

Valve clearance (both when hot and cold)

60-20

Standard dimension 28.6 28.6

Target (Nm {kg})

Range (Nm {kg})

59 {6.0}

53 to 65 {5.4 to 6.6}

Valve Intake side Exhaust side

Standard 0.33 0.71

Replace rocker arm shaft Replace rocker arm Replace rocker arm or rocker arm shaft Replace rocker arm shaft Tighten

Tolerance ±0.02

Adjust

125E-6 SERIES

60 Maintenance standard Crosshead and guide

Crosshead and guide

No.

(ENG125-A790-034-K-00-A)

Item Inside diameter of crosshead

1 Outside diameter of crosshead guide Protrusion of crosshead 2 guide

125E-6 SERIES

Unit: mm Remedy

Criteria Standard dimension 11 11 45.5

Tolerance +0.075 +0.025 +0.011 0 ±0.25

Repair limit 11.18

Replace

10.95 –

Correct

60-21

60 Maintenance standard Flywheel

Flywheel

(ENG125-A560-034-K-00-A)

a Tighten the flywheel mounting bolts with an impact wrench in the 1st stage and then tighten them with a torque wrench in the 2nd stage. A: Tightening order of flywheel mounting bolts B: Tightening order of flywheel housing mounting bolts

60-22

125E-6 SERIES

60 Maintenance standard Flywheel

No.

Item Facial runout of flywheel 1 housing Radial runout of flywheel 2 housing

Criteria Repair limit: 0.35 Repair limit: 0.30 Bolt

Tightening torque of 3 flywheel housing mounting bolt

M16

M10 4 Facial runout of flywheel 5 Radial runout of flywheel Procedure Tightening torque of flywheel mounting bolt 6 (apply engine oil to threads)

1st stage 2nd stage

Unit: mm Remedy Correct by reassembling

Target (Nm Range (Nm {kgm}) {kgm}) 147 to 235 1st stage 191 {19.5} {15 to 24} Tighten 245 to 309 2nd stage 279 {28.5} {25 to 31.5} 59 to 74 69 {7} – {6 to 7.5} Repair limit: 0.20 Correct by reassembling Repair limit: 0.15 Target (Nm {kgm}) Range (Nm {kgm}) 127 to 167 147 {15} Tighten {13 to 17} 270 to 309 289 {29.5} {27.5 to 31.5}

Procedure

a Do not use a flywheel mounting bolt more than 5 times. Each time the bolt is used, make a punch mark on its head.

125E-6 SERIES

60-23

60 Maintenance standard Main relief valve

Lubrication system (ENG107-AB00-001-K-00-A) Main relief valve

No.

Item Relief valve cracking 1 pressure

60-24

(ENG125-PQ91-034-K-00-A)

Criteria Standard: 0.65 to 0.8 MPa {6.63 to 8.16 kg/cm2}

Unit: mm Remedy Correct or replace spring

125E-6 SERIES

60 Maintenance standard Safety valve

Safety valve

No.

(ENG125-ABD0-034-K-00-A)

Item Safety valve cracking 1 pressure

125E-6 SERIES

Criteria Standard: 343 ± 19 kPa {3.5 ± 0.2 kg/cm2}

Unit: mm Remedy Replace

60-25

60 Maintenance standard Oil cooler

Cooling system (ENG107-B110-001-K-00-A) Oil cooler

(ENG125-B810-034-K-00-A)

a The shape is subject to machine models. No.

Item Full open lift of thermostat 1 Opening/closing of thermostat

60-26

Unit: mm Remedy Criteria Min. 8 mm (check by soaking in oil at 85 °C for 4 to 5 minutes) Replace When valve full open (85 °C) is soaked in oil at full closing temperature (71 °C) for 4 to 5 minutes, it must close fully.

125E-6 SERIES

60 Maintenance standard Water pump

Water pump

No.

(ENG125-BA10-034-K-00-A)

Item

Interference between 1 impeller and shaft

Interference between drive 2 gear and shaft Clearance between impeller 3 and body 4 Wear of water seal ring

125E-6 SERIES

Standard dimension

Criteria Tolerance Shaft Hole

15.9

+0.018 +0.005

-0.027 -0.044

20.0

+0.015 +0.002

-0.023 -0.053

Unit: mm Remedy Standard Replace interference Normally, replace impeller (Shaft 0.032 to outside diameter 0.062 changes little) Replace 0.025 to (Normally, replace 0.068 gear)

Standard clearance: 0.5 to 1.3 (including end play)

Replace

Limit of size: 1.5

60-27

60 Maintenance standard Thermostat

Thermostat

No.

(ENG125-BA30-034-K-00-A)

Item Full open lift of thermostat 1 Opening/closing of thermostat

60-28

Unit: mm Remedy

Criteria Min. 9 mm (Check by soaking valve in oil at 90 °C for 4 to 5 minutes) Replace When valve full open (90 °C) is soaked in oil at full closing temperature (71 °C) for 4 to 5 minutes, it must close fully.

125E-6 SERIES

INDEX

INDEX A

Aftercooler ................................................... 10-16 Air cleaner...................................................... 10-9 Alternator ..................................................... 10-87 Alternator mounting....................................... 10-91 Applicable machines ....................................... 01-6

General assembly of engine .......................... 50-35 General disassembly of engine ...................... 50-14 General view ................................................ 01-10

Handling equipment of fuel system devices..... 00-17 Handling of electrical equipment .................... 00-24 Handling of hydraulic equipment .................... 00-19 Handling of intake system parts ..................... 00-18 How to read electric wire code ....................... 00-32 How to read the shop manual ........................ 00-13 How to read this manual .................................. 50-3

Boost oil pump.............................................. 10-53

C Cam follower and push rod .............................. 60-9 Camshaft ..................................................... 60-17 Coating materials list....................................... 50-5 Components layout drawingt ........................... 10-3 Connecting rod ............................................. 60-13 Conversion table .......................................... 00-51 Cooling system circuit diagram ...................... 10-83 Cooling system parts layout drawing .............. 10-82 Crankshaft ..................................................... 60-8 Crosshead and guide .................................... 60-21 Cylinder block.......................................10-37, 60-5 Cylinder head .......................................10-35, 60-4 Cylinder liner .................................................. 60-7

E EGR cooler .................................................. 10-22 EGR system circuit diagram .......................... 10-19 EGR system piping drawing........................... 10-17 EGR valve ................................................... 10-20 Engine controller......................................... 10-100 Engine front oil seal replacement procedure.... 50-85 Engine performance curve............................. 01-26 Engine rear oil seal replacement procedure .... 50-88 Engine wiring harness ................................... 10-98 Exhaust gas regulation.................................... 01-3 Explanation of terms for maintenance standard ...0015

F Flywheel ...................................................... 60-22 Flywheel and flywheel housing....................... 10-49 Front cover................................................... 10-45 Fuel dozing .................................................. 10-76 Fuel feed pump ............................................ 10-96 Fuel feed pump switch .................................. 10-97 Fuel system circuit diagram ........................... 10-60 Fuel system parts layout drawing ................... 10-58

I Important safety notice .................................... 00-5 Intake and exhaust system circuit diagram ........ 10-7 Intake and exhaust system layout drawing ........ 10-6

K KCCV layout drawing .................................... 10-25 KCCV ventilator............................................ 10-27 KDPF .......................................................... 10-31 KVGT ..................................................10-10, 60-3

L List of abbreviation........................................ 00-46 Lubrication system diagram ........................... 10-51 Lubrication system parts layout drawing ......... 10-50

M Main filter ..................................................... 10-81 Main moving parts ........................................ 10-39 Main relief valve............................................ 60-24 Method of disconnecting and connecting of push-pull type coupler ................................. 00-21 Mixing connector .......................................... 10-24

O Oil cooler ........................................... 10-55, 60-26 Oil cooler thermo-valve ................................. 10-56 Oil filter ........................................................ 10-54 Oil pan ......................................................... 10-57 Oil pump ...................................................... 10-52 Outline of CRI system ................................... 10-63

P Piston .......................................................... 60-11 125E-6 SERIES

INDEX

Pre-filter ....................................................... 10-80 Precautions when performing operation.......... 00-35

R Removal and installation procedure of supply pump as single component .......................... 50-80 Rocker arm .................................................. 60-20 Running-in standard and performance test standard....................................................... 20-9

S Safety valve ................................................. 60-25 Sensor....................................................... 10-106 Sketch of special tool .................................... 50-11 Special tool list ............................................... 50-9 Specifications .........................................01-3, 01-7 Standard tightening torque table .................... 00-40 Standard value table for engine........................ 20-3 Starting motor............................................... 10-92

T Thermostat......................................... 10-85, 60-28 Timing gear ........................................ 10-43, 60-16

V Valve and valve guide ................................... 60-18 Valve system ................................................ 10-46 Vibration damper ................................ 10-42, 60-15

W Water pump ....................................... 10-84, 60-27 Weight table ................................................. 01-24 With built-in safety relay (11kW) ..................... 10-94 With built-in safety relay (7.5kW) .................... 10-92

125E-6 SERIES

125E-6 SERIES ENGINE Form No. SEN05624-05