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Home / Wheel Loaders / Komatsu Wheel Loaders / Komatsu WA70M-8

Komatsu WA70M-8 Troubleshooting

The Komatsu WA70M-8 wheel loader driveline system components: Komatsu 4D98E-6SHA four-cylinder water-cooled diesel engine with a rated power of 62 hp (42.6 kW), and two-range hydrostatic transmission. The hydraulic system has a pump with a rated capacity of 15.8 gal/min (60 l/min). The system relief pressure is 3335 psi (230 bar). The Komatsu WA70M-8 is equipped with a power steering system, hydraulic disc brakes, and 365/70R18 tires. The wheel loader has a max lift height to hinge pin of 123.4" (3135 mm) and breakout force of 8975 lbs (4080 kg). The rated operating capacity is 4640 lbs (2110 kg), and tipping load is 9280 lbs (4220 kg).

Engine Troubleshooting

Engine hard to start or doesn't start
Air in fuel system - Bleed fuel system.
Dirty fuel filter - Change the filter element.
Burnt or clogged injection nozzle - Service or change injection nozzles.
Water in the fuel system - Change fuel and repair fuel system.
Valve out of adjustment - Correct valve clearance needs to be set.
Faulty fuel injection pump - Replace or repair injection pump.

Engine starts but stops suddenly
Dirty air cleaner - Clean or change.
Fuel filter element is clogged - Service or replace the filter.
Fuel injection pump is leaking - Repair any leaks.
Clogged or defective injectors - Inspect fuel injectors and change as required.
Fuel injection pump is broken - Change or repair the pump.

Engine stops running suddenly
Coolant temperature is low - Warm up the engine.
Fuel filter element is clogged - Service or replace the filter.
Air in fuel system - Bleed fuel system.
Fuel injection nozzles are faulty or clogged - Check injection nozzles and replace if required.
Timing of fuel injection pump is incorrect - Set the fuel pump timing correctly.

Engine stops while idling
Too low idle RPM - Adjustment required.
Fuel injection pump is damaged - Rebuild or change fuel pump.
Fuel injector fault - Clean or replace fuel injectors.
Incorrect valve clearance - Need to adjust valve clearance.

Engine loses power
Clogged air cleaner - Clean or replace air cleaner element.
Fuel injection nozzles are faulty or clogged - Clean or replace injection nozzles.
Incorrect fuel injection pressure - Adjust pressure to proper level.
Valve clearance is not correct - Correct valve clearance.
Incorrectly set low idle speed - Correct low idle adjustment.
Fuel hoses or lines are dirty - Clean fuel system hoses and lines.
Cylinder head gasket is defective - Install a new gasket.
Piston rings are defective or leaking - Change piston rings.

Engine is overheated
Lack of engine coolant - Fill radiator to proper level and check components for faults.
Lack of engine oil - Check and refill engine oil.
Faulty radiator cap or dirty radiator fins - Replace cap or clean radiator.
Broken or loose fan belt - Change as required.
Engine overloaded - Reduce engine load.

Oil pressure is insufficient
Not enough oil in the engine - Check oil level and add oil as required.
Clogged oil filter element - Service or replace engine oil filter.
Improper type of engine oil - Use proper viscosity oil.
Crankshaft bearing oil clearance is incorrect - Bearings need to be reinstalled.
Oil pump failure - Check and replace if necessary.

Engine noise or knocking
Insufficient engine oil - Need to add engine oil.
Engine not warmed up - Warm up the engine.
Fuel injection pump timing is wrong - Adjust as recommended.
Incorrect low idle setting - Adjust low idle speed.
Fuel injector fault - Clean fuel injectors or change it.
Connecting rod is not aligned or defective - Connecting rod needs to be aligned or changed.
Pistons are worn or broken - Replace the pistons as required.

Hydrostatic Transmission Troubleshooting

HST transmission is making noise
Transmission oil is contaminated or oil level is insufficient - Add oil to proper level or pour fresh transmission oil.
Speed control linkage is defective or unadjusted - Adjust or replace linkage.
Relief valve failure - Install a new valve.
Excessive transmission load - Reduce transmission load.
Transmission parts are worm or defective - Check internal transmission parts for damage or wear and replace if required.

Lack of power
Transmission oil level is low - Check and refill the transmission oil.
Relief valve is stuck - Install a new valve.
Speed control linkage is worn or unadjusted - Change or adjust linkage.

Transmission oil overheats
Insufficient transmission oil - Fill the transmission housing to proper oil level.
Dirty transmission fluid filter element - Replace or service transmission fluid filter.
Cooling components are clogged or damaged - Inspect all cooling components and replace or repair if necessary.
Transmission overload - Reduce loading.

External oil leaks
Seals or gaskets are broken - Install new gaskets or seal.
High internal transmission case pressure - Replace worn components.
Oil return tube is plugged - Clean or replace the tube.

Hydraulics Troubleshooting

Hydraulic system overheating
Hydraulic pressure incorrectly adjusted - Adjust pressure correctly.
Unadjusted or defective main relief valve - Adjust or change relief valve.
Hydraulic fluid is contaminated - Change hydraulic fluid.
Lack of hydraulic fluid - Check and refill the hydraulic fluid.
Hydraulic pump is worn - Repair or install new hydraulic pump.

Lift arm can't drop or lift
Lift controls are defective - Inspect and repair if necessary.
Hydraulic pump not working - Repair or install new hydraulic pump.
Faulty hydraulic control valve - Repair or replace the valve.
Hydraulic cylinder malfunction - Change or repair lift cylinder.
Low hydraulic fluid level - Add fluid as required.

Bucket won't move
Bucket tilt controls are defective - Inspect and repair if necessary.
Hydraulic pump not working - Repair or change pump if required.
Hydraulic control valve malfunction - Repair or replace the valve.
Bucket cylinder failure - Replace or repair cylinder.
Insufficient hydraulic fluid - Checking hydraulic fluid level and add if necessary.

Slow bucket or lift arm operation
Hydraulic pump is faulty - Flow-rate pump and change pump if necessary.
Leaking hydraulic cylinder - Replace cylinder piston seals.
Hydraulic fluid level low - Fill up the hydraulic fluid.
Defective or not adjusted hydraulic control valve - Repair or set correctly.
Low hydraulic pressure - Adjust pressure correctly.

Bucket or boom jerks when working
Hydraulic system is leaking air - Bleed hydraulic system.
Hydraulic oil filter element clogging - Clean or replace the filter.
Dirty hydraulic oil - Hydraulic oil change required.
Cylinder rod or tube is scratched - Replace failed component.

Hydraulic pump is noisy
Leaking hydraulic system or insufficient oil level - Top up hydraulic oil or remedy leakage in system.
Hydraulic filter clogging - Replace or clean the filter.
Plugged suction line - Service the suction line.
Air in hydraulic pump - Air bleeding is required.
Damaged pump parts - Change or rebuild pump.

Electrical Troubleshooting

Battery won’t charge
Corroded or loose cable connections - Clean or tighten connections.
Electrical terminal connectors are defective - Terminal connectors should be replaced.
Worn-out battery - Replace the battery.
Loose or damaged belt - Belt needs to be adjusted or replaced.

Starter turns slow
Low battery capacity - Battery is drained, recharge it.
Battery will not hold charge - Service battery or replace it.
Wires are disconnected or battery terminals are corroded - Check battery wires and service or replace terminals.

Starter is not cranking
Battery is drained or worn - Charge or change the battery.
Battery wiring is disconnected or improperly connected - Inspect wiring and connect as required.
Battery capacity is low - Charge the battery.
Starter motor is faulty - Repair or install a new starter.

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WHEEL LOADERS SPECIFICATIONS

Caterpillar