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Home / Wheel Loaders / Komatsu Wheel Loaders / Komatsu WA120-3 |
Komatsu WA120-3 Troubleshooting
The
Komatsu WA120-3 wheel loader driveline system components: 238 cu.in (3.9L)
Komatsu S4D102E-1 4-cylinder turbocharged diesel engine with a rated power of 91
hp (67 kW), and 4x4 full powershift transmission. The hydraulic system has a
pump with a rated capacity of 30.3 gal/min (115 l/min). The system relief
pressure is 3050 psi (210 bar). The Komatsu WA120-3 is equipped with a power
steering system, hydraulic wet disc brakes, and 17.5x25 tires. The wheel loader
has a maximum lift height of 136.8" (3475 mm) and bucket breakout force of 16250
lbs (7385 kg). The rated operating capacity is 7700 lbs (3500 kg), and tipping
load is 15400 lbs (7000 kg).
Engine Troubleshooting |
Diesel engine hard to start or doesn't start
Air in the fuel system - Air bleeding.
Fuel filter element clogging - Service the filter.
Damaged or dirty 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 - Correct valve clearance needs to be set.
Fuel injection pump is faulty - Repair or install a new fuel pump.
Engine starts and stalls suddenly
Air cleaner is clogged - Clean or change.
Fuel filter element clogging - Change or clean the filter element.
Fuel injection pump has loose connections - Tighten the connections.
Fuel injectors are faulty or clogged - Replace or clean fuel injectors.
Fuel injection pump is not working correctly - Install a new fuel pump or repair.
Engine shuts off while running
Engine is not preheated - Warm up to required temperature.
Fuel filter is plugged - Change the filter element.
Air in the fuel system - Air bleeding.
Clogged or defective injection nozzles - Check and replace nozzles if required.
Timing of fuel injection pump is incorrect - Adjust the pump as required.
Engine stalls while idle
Improperly adjusted low idle speed - Adjust the low idle speed.
Fuel injection pump is defective - Replace injection pump or repair it.
Fuel injector fault - Change or clean fuel injectors.
Incorrect valve clearance - Check and adjust as required.
Engine power is insufficient
Air cleaner is dirty - Clean or replace air cleaner element.
Fuel injection nozzles are damaged or dirty - If necessary, replace with a new nozzle.
Incorrect fuel injection pressure - Check the fuel injection pressure and adjust if necessary.
Valve clearance is out of adjustment - Adjust valve clearance.
Low idle speed setting is not correct - Adjust the low idle speed.
Fuel hoses or lines clogging - Clean fuel system lines and hoses.
Leaking cylinder head gasket - Install a new gasket.
Piston rings are worn or damaged - Install new piston rings.
Engine overheated
Low engine coolant - Add coolant fluid to cooling system and also check it for leaks.
Lack of engine oil - Check and refill engine oil.
Radiator fins are clogged or radiator cap is faulty - Install new cap or clean radiator.
Loose or damaged fan belt - Replace the fan belt.
Engine is overloaded - Reduce engine load.
Oil pressure is insufficient
Engine oil insufficient - Check oil level and add oil as required.
Oil filter element clogging - Change or service engine oil filter.
Oil grade or viscosity is incorrect - Use the specified type of engine oil.
Crankshaft bearing has incorrect oil clearance - Replace bearings.
Oil pump malfunction - Repair or replace.
Engine noises or knocks
Engine oil level low - Checking oil level and add if necessary.
Low coolant temperature - Warm up the engine.
Incorrect adjustment of fuel injection pump timing - Adjust fuel injection pump as required.
Low idle speed set incorrectly - Correct low idle settings.
Fuel injector fault - Change or clean fuel injectors.
Misaligned or defective connecting rod - Align or replace connecting rod.
Broken or worn pistons - Pistons need to be replaced.
Transmission Troubleshooting |
Transmission oil pressure is insufficient
Lack of transmission oil supply - Fill the transmission housing to proper oil level.
Dirty transmission oil filter element (if equipped) - Service or replace the transmission oil filter.
Relief valve is stuck - Install a new valve.
Transmission makes noise
Transmission fluid insufficient - Need to add transmission fluid.
Transmission fluid is contaminated - Change the fluid.
Improper backlash or worn gears - Install new gears and adjust backlash properly.
Bearings are damaged or worn - Replace faulty bearings.
Worn or damaged gear shift forks - Install new shift forks.
Shaft splines are worn or damaged - Shaft need to be changed.
Gear shift is hard
Worn or rusty gear shift linkage - Lubricate or replace shift linkage.
Shift forks are bent or worn out - Replace the shift forks.
Worn out parts of the gearshift mechanism - Replace worn parts.
Clutch is faulty or misadjusted - Clutch adjustment or replacement required.
Transmission fluid leakage
Transmission oil level is exceeded - Correct the oil volume.
Damaged gaskets or seals - Change defective gaskets or seal.
Hydraulics Troubleshooting |
Hydraulic system overheated
Hydraulic pressure is not correct - Correct setting is required.
Defective or misadjusted main relief valve - Adjust the valve or replace if necessary.
Hydraulic oil is contaminated - Fill up with fresh hydraulic oil.
Hydraulic oil level is insufficient - Fill up the hydraulic oil.
Hydraulic pump is faulty - Install new pump or repair it.
Lift arm does not lower or raise
Damaged lift controls - Change or repair.
Hydraulic pump malfunction - Repair or change pump if required.
Defective hydraulic control valve - Install a new valve or repair it.
Faulty hydraulic cylinder - Change or repair lift cylinder.
Hydraulic fluid level low - Add fluid as required.
Bucket won't move
Bucket controls are faulty - Repair or replace.
Hydraulic pump malfunction - Install new pump or repair it.
Faulty hydraulic control valve - Install a new hydraulic valve or repair it.
Damaged bucket cylinder - Repair or change cylinder.
Hydraulic oil level low - Need to add oil.
Boom or bucket runs slowly
Hydraulic pump is defective - Check the pump capacity and replace pump if required.
Leaking hydraulic cylinder - Replace cylinder piston seals.
Low hydraulic oil level - Fill the system to proper hydraulic oil level.
Hydraulic control valve is unadjusted or worn - Repair or set correctly.
Low hydraulic pressure - Hydraulic pressure must be set correctly.
Lift arm or bucket is moving jerkily
Hydraulic system is leaking air - Air bleeding is required.
Plugged hydraulic oil filter - Clean or install new filter.
Hydraulic oil is dirty - Fill up with fresh hydraulic oil.
Cylinder rod or tube is scratched - Change worn component.
Hydraulic pump is noisy
Hydraulic system leaking or not enough oil - Remedy hydraulic leakage or refill oil as necessary.
Hydraulic filter is dirty - Service or replace hydraulic filter.
Suction line is clogged - Service the suction line.
Pump sucks air - Bleed air from hydraulics.
Pump parts are damaged - Rebuild or install new pump.
Electrical Troubleshooting |
Battery won’t charge
Loose or corroded electrical wiring connections - Tighten or service connections.
Faulty battery terminal clamps - Replace terminal clamps.
Battery faulty cell - Change the battery.
Loose or defective belt - Change belt or adjust belt tension.
Starter cranks slowly
Low battery voltage - Recharge the battery.
Battery does not hold charge - Battery needs service or replacement.
Corroded battery terminals or disconnected wires - Connect wires correctly or change terminals.
Starter doesn't crank
Battery is drained or worn - Charge or change the battery.
Battery wiring is disconnected or improperly connected - Inspect wiring and connect as required.
Low battery output voltage - Low battery charging, charge as required.
Defective starter motor - Repair or replace starter.
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