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Home / Wheel Loaders / Komatsu Wheel Loaders / Komatsu WA75-3

Komatsu WA75-3 Troubleshooting

The Komatsu WA75-3 wheel loader is powered by 202 cu.in (3.3L) Komatsu 4D98E 4-cylinder water-cooled diesel engine with a rated power of 58 hp (42.5 kW) at 2200 rpm. The Komatsu WA75-3 is equipped with a two-range hydrostatic transmission, power steering system, hydraulic wet disc brakes, and 405/70R18 standard tires. The hydraulic system has a pump with fluid flow rate of 16.9 gpm (64 lpm). The hydraulic pressure is 2970 psi (205 bar). The wheel loader has a rated operating capacity of 4090 lbs (1860 kg) and tipping load of 8180 lbs (3720 kg). The maximum lift height is 125.8" (3195 mm) to hinge pin, and bucket breakout force is 10780 lbs (4900 kg).

Engine Troubleshooting

Engine difficult to start or will not start
There is air in the fuel system - Bleed the system.
Clogged fuel filter - Clean the filter element.
Dirty or damaged injection nozzles - If necessary, replace with a new nozzle.
Water or dirt in fuel system - Drain, flush, and service the system.
The valve clearance is incorrect - Adjust valve clearance.
Fuel injection pump is not operating properly - Repair or change injection pump.

Diesel starts and stalls immediately
Plugged air cleaner - Install new air cleaner element.
Fuel filter plugged - Clean or replace the filter.
Fuel injection pump leakage - Check the fuel injection pump for leaks and fix it.
Defective or clogged fuel injectors - Clean fuel injectors or change it.
Fuel injection pump is not operating properly - Replace or repair injection pump.

Engine stops unexpectedly during operation
Engine is cold - Warm up to required temperature.
Fuel filter element clogging - Change filter element.
Air in fuel system - Bleed fuel system.
Fuel injection nozzles are dirty or defective - Replace injection nozzles.
Improper fuel injection timing - Set it up as required.

Engine stalls while idle
Incorrectly set low idle speed - Normalize low idle speed.
Fuel injection pump is defective - Replace or rebuild injection pump.
Clogged or defective injectors - Clean fuel injectors or change it.
The valve clearance is incorrect - Adjustment procedure required.

Engine loses power
Dirty air cleaner - Install new air cleaner element.
Dirty or damaged injection nozzles - Check injection nozzles and replace if required.
Fuel injection pressure is wrong - Test fuel injection pressure and adjust it correctly.
Incorrect valve clearance - Check and adjust.
Incorrect low idle setting - Adjustment required.
Clogged fuel lines or hoses - Service fuel hoses and lines.
Defective cylinder head gasket - Install new cylinder head gasket.
Piston rings are broken or leaking - Replace the piston rings as required.

Engine is overheated
Insufficient coolant fluid - Add coolant fluid and inspect the cooling system for leaks.
Engine oil level is low - Fill up the oil to required level.
Defective radiator cap or clogged radiator fins - Clean radiator or change cap.
Damaged or worn fan belt - Change as required.
Engine is overloaded - Load reducing is recommended.

Oil pressure is low
Low oil level - Check and refill the oil.
Clogged oil filter - Clean or change engine oil filter.
Different type of engine oil - Use the specified type of engine oil.
Excessive main bearing oil clearance - Bearings need to be reinstalled.
Oil pump malfunction - Remove and inspect oil pump.

Engine noises or knocks
Engine oil level is insufficient - Checking oil level and add if necessary.
Engine is cold - Warm up engine as required.
Improper fuel injection timing - Adjust according to specifications.
Low idle speed adjustment is incorrect - Correct low idle adjustment.
Damaged or clogged injectors - Replace fuel injectors.
Connecting rod is misaligned or worn - Need to align or replace the connecting rod.
Worn or broken pistons - Have pistons replaced.

Hydrostatic Transmission Troubleshooting

HST transmission noise
Transmission oil is contaminated or oil level is insufficient - Fill to required level or change the transmission oil.
Bent or unadjusted speed control pedal linkage - Replace or adjust linkage.
Relief valve is damaged - Change relief valve.
Excessive transmission load - Reduce loading.
Transmission parts are worm or defective - Check internal transmission parts for damage or wear and replace if required.

Low power
Transmission fluid insufficient - Need to add transmission fluid.
Defective relief valve - Install a new relief valve.
Speed control linkage is worn or unadjusted - Adjust or change linkage.

Transmission fluid is too hot
Insufficient transmission fluid - Check and refill the transmission fluid.
Dirty transmission fluid filter element - Replace or service transmission fluid filter.
Clogged or damaged cooling components - Check all cooling components and clean or replace if required.
Transmission overloaded - Load needs to be reduced.

Transmission oil leaking
Seals or gaskets are broken - Install new components.
High internal transmission housing pressure - Repair or replace damaged components.
Oil drain pipe is plugged - Check pipe and service if necessary.

Hydraulics Troubleshooting

Hydraulic system overheating
Hydraulic pressure is not adjusted correctly - Set pressure correctly.
Faulty or improperly adjusted main relief valve - Adjust relief valve or change if required.
Hydraulic oil is contaminated - Fill up with fresh hydraulic oil.
Not enough hydraulic oil in the system - Fill the hydraulic system with oil.
Hydraulic pump is worn - Repair or replace pump if necessary.

Lift arm won't raise or lower
Lift controls failure - Repair or replace.
Hydraulic pump malfunction - Repair or change pump if required.
Faulty hydraulic control valve - Replace or repair the valve.
Hydraulic cylinder is faulty - Repair or change hydraulic cylinder.
Hydraulic oil is insufficient - Checking hydraulic oil level and add if necessary.

Bucket fails to tilt
Defective bucket controls - Check and repair as required.
Hydraulic pump failure - Repair or change pump if required.
Faulty hydraulic control valve - Repair or replace hydraulic valve.
Broken bucket cylinder - Repair or install a new cylinder.
Hydraulic oil is insufficient - Fill the system to proper hydraulic oil level.

Slow boom or bucket action
Defective hydraulic pump - Check pump flow and install new pump if necessary.
Hydraulic cylinder leaking - Cylinder seals need to be replaced.
Hydraulic oil level low - Fill the system to proper hydraulic oil level.
Damaged or incorrect adjusted hydraulic control valve - Repair or adjust properly.
Hydraulic pressure has dropped - Adjust it correctly.

Bucket or boom is working jerkily
Air leaks in hydraulic system - Bleed air from system.
Hydraulic oil filter is dirty - Clean or replace the filter.
Contaminated hydraulic fluid - The fluid must be changed.
Cylinder rod or tube is scratched - Change defective component.

Hydraulic pump is excessively noisy
Low oil level or hydraulic leaks - Correct hydraulic leaks or top up oil as needed.
Dirty hydraulic filter - Change or clean oil filter.
Suction line clogging - Service the suction line.
Air trapped in hydraulic pump - Bleed air.
Pump components are damaged - Rebuild or change hydraulic pump.

Electrical Troubleshooting

Battery is not charging
Corroded or loose wire connections - Tighten or service connections.
Battery terminal clamps are defective - Terminal clamps need to be replaced.
Faulty cell in battery - Change the battery.
Damaged or loose belt - Replace belt or adjust belt tension.

Starter turns slow
Low battery output voltage - Battery is drained, recharge it.
Battery does not hold charge - Service or replace the battery.
Corroded battery terminals or disconnected wires - Check wire connections and change or service terminals.

Starter is not cranking
Battery is discharged or worn - Recharge or change battery.
Wire harness is disconnected or incorrectly connected - Check wire harness and connect as required.
Low battery voltage - Recharge the battery.
Starter motor is faulty - Change or repair starter.

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WHEEL LOADERS SPECIFICATIONS

Caterpillar