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Home / Wheel Loaders / Komatsu Wheel Loaders / Komatsu WA50-6

Komatsu WA50-6 Troubleshooting

The Komatsu WA50-6 compact wheel loader is powered by 135 cu.in (2.2L) Komatsu 4D88E-6B 4-cylinder direct injection water-cooled diesel engine with a rated power of 38.6 hp (28.7 kW) at 2400 rpm. The Komatsu WA50-6 is equipped with a hydrostatic transmission, hydraulic power steering, hydraulic wet disc brakes, and 15.5/60-18 standard tires. The open center hydraulic system has a pump with fluid flow rate of 12.2 gpm (46.5 lpm). The wheel loader has a rated operating capacity of 2845 lbs (1290 kg) and tipping load of 5690 lbs (2580 kg). The max lift height is 122.8 inches (3120 mm) to hinge pin, and boom breakout force is 6720 lbs (3050 kg).

Engine Troubleshooting

Engine starts hard or doesn't start
Air in the fuel lines - Bleed the fuel lines.
Fuel filter plugging - Clean the filter or install new filter element.
Burnt or defective injection nozzle - Service or change injection nozzles.
Dirt or water in fuel system - Drain water or flush dirt from the system.
Valve out of adjustment - Need to adjust valve clearance.
Fuel injection pump is defective - Rebuild or replace pump.

Diesel starts but stalls suddenly
Plugged air cleaner - Service or replace air cleaner.
Dirty fuel filter - Change the filter element.
Fuel injection pump has loose connections - Tighten the connections.
Damaged or clogged injectors - Replace fuel injectors.
Fuel injection pump damage - Rebuild or replace pump.

Engine stalls during operation
Engine is cold - Normalize the temperature by warming up the engine.
Fuel filter element clogging - Install new filter element.
Air trapped in fuel system - Bleed air.
Fuel injection nozzles are faulty or clogged - Clean or change injection nozzles.
Improper fuel injection timing - Adjust the pump as required.

Engine stops at low idle speed
Incorrect low idle setting - Adjust as required.
Fuel injection pump is damaged - Replace or rebuild injection pump.
Clogged or defective injectors - Replace or clean fuel injectors.
Valve clearance is not correct - Check and adjust.

Diesel engine loses power
Clogged air cleaner - Install new air cleaner element.
Dirty or damaged injection nozzles - If necessary, replace with a new nozzle.
Fuel injection pressure is incorrect - Correct the pressure settings.
Valve out of adjustment - Adjust valve clearance.
Too low idle RPM - Normalize low idle speed.
Fuel hoses or lines are clogged - Service fuel hoses and lines.
Worn cylinder head gasket - Install new cylinder head gasket.
Leaking or defective piston rings - Change piston rings.

Engine overheating
Engine has a lack of coolant - Refill to the correct level and inspect system for leaks.
Engine oil level low - Fill the crankcase with engine oil.
Radiator fins are dirty or radiator cap is defective - Clean radiator or install new cap.
Loose or damaged fan belt - The fan belt needs to be replaced.
Diesel engine is overloaded - Load reducing required.

Oil pressure is insufficient
Not enough oil in the engine - Check and refill the oil.
Clogged oil filter - Replace or clean engine oil filter element.
Improper type of engine oil - Use oil of correct viscosity.
Excessive crankshaft bearing oil clearance - Install new bearings.
Oil pump is defective - Check and replace if necessary.

Engine noise or knocking
Engine oil level is insufficient - Checking oil level and add if necessary.
Coolant temperature is low - Warm up engine as required.
Fuel injection pump timing is wrong - Use the correct fuel injection pump timing adjustment.
Incorrectly adjusted low idle speed - Test and adjust.
Defective fuel injectors - Replace fuel injectors.
Faulty or misaligned connecting rod - Alignment procedure or replacement is required.
Pistons are broken or worn - Pistons need to be replaced.

Hydrostatic Transmission Troubleshooting

HST transmission noise
Transmission fluid is dirty or fluid level is too low - Top up to proper level or change transmission fluid.
Bent or unadjusted speed control pedal linkage - Repair or adjust linkage.
Relief valve is damaged - Change the valve.
Transmission overloaded - Reduce transmission load.
Damaged or worn components of hydrostatic transmission - After disassembly and inspection, replace defective components.

Power is too low
Transmission fluid insufficient - Fill the transmission housing to proper fluid level.
Stuck relief valve - Replace the valve.
Speed control linkage is defective or unadjusted - Change or adjust linkage.

Transmission oil overheating
Transmission fluid insufficient - Check and refill the transmission fluid.
Transmission oil filter element clogging - Clean or replace the transmission filter.
Defective or plugged cooling components - Inspect all cooling components and replace or clean if necessary.
Transmission overloaded - Reduce loading.

External oil leaks
Broken seals or gaskets - Change defective seal or gaskets.
High internal transmission case pressure - Check transmission parts for damage or wear and replace if required.
Clogged oil drain line - Clean or replace drain line.

Hydraulics Troubleshooting

Hydraulic system overheated
Hydraulic pressure incorrectly adjusted - Adjust it correctly.
Misadjusted or defective main relief valve - Adjust the valve or replace if necessary.
Hydraulic fluid is dirty - Change hydraulic fluid.
Hydraulic fluid level is insufficient - Add fluid to the hydraulic system.
Faulty hydraulic oil pump - Repair or change pump if required.

Boom fails to lift or drop
Faulty lift controls - Repair or change.
Defective hydraulic pump - Repair or change pump if required.
Defective hydraulic control valve - Repair or replace hydraulic valve.
Hydraulic cylinder failure - Repair or replace hydraulic cylinder.
Low hydraulic fluid level - Add fluid as required.

Bucket does not function
Faulty bucket tilt controls - Repair or change.
Hydraulic pump failure - Repair or install new hydraulic pump.
Damaged hydraulic control valve - Install a new hydraulic valve or repair it.
Hydraulic bucket cylinder is broken - Repair or replace cylinder.
Insufficient hydraulic fluid - Add fluid as required.

Boom or bucket moves slowly
Worn hydraulic oil pump - Test pump performance and replace pump if necessary.
Leaking hydraulic cylinder - Change cylinder piston seals.
Insufficient hydraulic fluid - Fill the system to proper hydraulic fluid level.
Damaged or incorrect adjusted hydraulic control valve - Repair or set properly.
Hydraulic pressure is low - Adjust pressure as required.

Lift arm or bucket is moving jerkily
Hydraulic system is leaking air - Air bleeding is required.
Hydraulic oil filter element is dirty - Clean or change the filter.
Hydraulic oil contamination - Change hydraulic oil.
Scratched cylinder rod or tube - Replace damaged component.

Hydraulic pump makes excessive noise
Lack of oil or hydraulic leakage - Add hydraulic oil or correct system leaks.
Plugged hydraulic filter - Change or clean oil filter.
Suction line is clogged - Service the suction line.
Air trapped in hydraulic pump - Bleed air.
Faulty pump parts - Rebuild or install new pump.

Electrical Troubleshooting

Battery will not charge
Wiring connections are corroded or loose - Tighten or clean electrical wiring connections.
Battery terminal connectors are defective - Terminal connectors should be replaced.
Bad cell in battery - Battery change required.
Worn or loose belt - Install a new belt or adjust belt tension.

Starter motor cranks slow
Low battery output - Charge the battery.
Battery won’t hold charge - Service or change the battery.
Faulty battery terminals or disconnected cables - Check cables and clean or change terminals.

Starter motor is not working
Battery is discharged or defective - Battery needs to be recharged or replaced.
Wiring is improperly connected or disconnected - Check wiring and connect properly.
Low battery capacity - Battery needs to be recharged.
Starter motor failure - Replace or repair starter.

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WHEEL LOADERS SPECIFICATIONS

Wheel Loaders, Skid Steers, and Compact Track Loaders