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Home / Wheel Loaders / Hitachi Wheel Loaders / Hitachi ZW50-5B

Hitachi ZW50-5B Troubleshooting

The Hitachi ZW50-5B wheel loader is powered by Kubota D1803-CR-TI-E4 four-stroke three-cylinder direct injection turbocharged liquid-cooled diesel engine with a rated power of 42 hp (31.8 kW) at 2400 rpm. The Hitachi ZW50-5B is equipped with a 2-speed hydro transmission, hydraulic power steering, hydraulic wet disc brakes, and 15.5/60-18 standard tires. The hydraulic system has a pump with fluid flow rate of 13.9 gpm (52.7 lpm). The wheel loader has a rated operating capacity of 2380 lbs (1080 kg) and tipping load of 4760 lbs (2160 kg). The maximum lift height is 123.6 inches (3140 mm) to hinge pin, and boom breakout force is 5530 lbs (2510 kg).

Engine Troubleshooting

Engine difficult to start or will not start
Air trapped in fuel system - Bleed air.
Fuel filter element is dirty - Replace the filter element.
Burnt or clogged injection nozzle - Test injection nozzles and change if necessary.
Dirt or water in fuel system - Drain water or flush dirt from the system.
The valve clearance is not adjusted - Adjust valve clearance according to specifications.
Faulty fuel injection pump - Repair or change injection pump.

Engine starts but stops suddenly
Plugged air cleaner - Clean or change cleaner.
Fuel filter element is dirty - Change filter element.
Problems with fuel injection pump tightness - Inspect fuel injection pump for leaks.
Defective or clogged fuel injectors - Clean or replace fuel injectors.
Fuel injection pump is defective - Change pump or rebuild it.

Engine shuts off suddenly during operation
Low coolant temperature - Warm up to required temperature.
Dirty fuel filter - Clean or replace the filter.
Air in the fuel system - Air bleeding.
Faulty or dirty injection nozzles - Inspect nozzles and replace if necessary.
Improper fuel injection timing - Adjust the pump as required.

Engine stops while idle
Low idle speed setting is not correct - Correct the settings.
Fuel injection pump failure - Change pump or rebuild it.
Damaged or clogged injectors - Change or clean fuel injectors.
The valve clearance is incorrect - Adjust valve clearance.

Engine lacks power
Air filter is clogged - Service or replace the air filter.
Fuel injection nozzles are damaged - Clean or replace injection nozzles.
Incorrect fuel injection pressure - Test fuel injection pressure and adjust it correctly.
Excessive valve clearance - Adjust valve clearance.
Incorrect low idle setting - Adjustment required.
Dirt in the fuel lines or hoses - Fuel lines and hoses need to be cleaned.
Defective cylinder head gasket - Change cylinder head gasket.
Piston rings are worn or damaged - Replace piston rings.

Engine overheated
Lack of engine coolant - Fill the cooling system and check components for leaks or other faults.
Engine oil level is insufficient - Check and refill engine oil.
Defective radiator cap or clogged radiator core - Install new cap or clean radiator.
Loose or defective fan belt - If necessary, replace the belt.
Engine is overloaded - Reduce load on the engine.

Oil pressure is low
Engine oil level low - Checking oil level and add if necessary.
Clogged oil filter - Replace or service engine oil filter.
Oil grade or viscosity is wrong - Use oil of correct viscosity.
Crankshaft bearing has incorrect oil clearance - Bearing replacement required.
Oil pump is worn or damaged - Check and replace if necessary.

Engine knocks or noises
Not enough engine oil - Need to add engine oil.
Engine is not warmed up to required temperature - Normalize the temperature by warming up the engine.
Improper fuel injection timing - Set the fuel pump timing correctly.
Incorrect low idle setting - Normalize low idle speed.
Defective fuel injectors - Clean fuel injectors or change it.
Connecting rod failure or misalignment - Need to replace or align the connecting rod.
Broken or worn pistons - Have pistons replaced.

Hydrostatic Transmission Troubleshooting

HST transmission noise
Contaminated transmission fluid or low fluid level - Top up to proper level or change transmission fluid.
Speed control pedal linkage is bent or not adjusted - Change or adjust linkage.
Stuck relief valve - Install a new valve.
Transmission overloaded - The load should be reduced.
Transmission parts are worm or defective - Change or repair defective parts.

Loss of power
Transmission fluid insufficient - Check and refill the transmission fluid.
Relief valve failure - Change relief valve.
Speed control pedal linkage is bent or not adjusted - Replace or adjust linkage.

Transmission oil over heats
Low fluid level - Checking transmission fluid level and add if necessary.
Dirty transmission fluid filter element - Service or replace the transmission fluid filter.
Cooling components are clogged or damaged - Inspect all cooling components and service or change if necessary.
Excessive transmission load - Reduce the load is required.

Transmission oil leaking
Seals or gaskets are worn - Install new gaskets or seal.
High internal transmission housing pressure - Repair or replace damaged components.
Plugged transmission fluid return tube - Service or replace return tube.

Hydraulics Troubleshooting

Hydraulic system is overheated
Hydraulic pressure is not correct - Set pressure correctly.
Faulty or improperly adjusted main relief valve - Adjust or change relief valve.
Hydraulic fluid is contaminated - The fluid must be changed.
Hydraulic fluid level is insufficient - Need to add fluid.
Faulty hydraulic oil pump - Install new pump or repair it.

Boom won't lower or raise
Defective lift controls - Change or repair.
Hydraulic pump malfunction - Repair or change pump if required.
Hydraulic control valve malfunction - Install a new valve or repair it.
Damaged hydraulic cylinder - Replace or repair boom cylinder.
Hydraulic fluid is insufficient - Fill up the hydraulic fluid.

Bucket won't move
Bucket tilt controls are defective - Change or repair.
Damaged hydraulic oil pump - Repair or change pump if required.
Hydraulic control valve is defective - Repair or change hydraulic valve.
Hydraulic bucket cylinder is defective - Replace or repair cylinder.
Hydraulic oil level low - Fill the system to proper hydraulic oil level.

Slow boom or bucket operation
Hydraulic pump is worn - Test the pump flow rate and change pump if required.
Hydraulic cylinder leaking - Install new cylinder seals.
Insufficient hydraulic oil - Check and refill the hydraulic oil.
Defective or not adjusted hydraulic control valve - Adjust properly or repair.
Low hydraulic pressure - Set pressure correctly.

Jerky operation of the bucket or boom
There is air in the hydraulic system - Bleed air from hydraulic system.
Hydraulic oil filter is clogged - Service or replace the hydraulic filter.
Hydraulic oil is dirty - Hydraulic oil change required.
Cylinder rod or tube is scuffed - Change damaged component.

Excessive hydraulic pump noise
Hydraulic leaks or low oil level - Correct hydraulic leaks or top up oil as needed.
Dirty hydraulic filter - Clean or replace the filter.
Plugged suction line - Need to service the suction line.
Pump is sucking air - Bleed air from hydraulics.
Worn pump components - Install new hydraulic pump or rebuild it.

Electrical Troubleshooting

Battery will not charge
Loose or corroded cable connections - Tighten or clean electrical wiring connections.
Faulty battery terminal connectors - Terminal connectors should be replaced.
Battery is defective - Battery change required.
Worn or loose belt - Adjust belt tension or replace belt.

Starter cranks slow
Low battery power - Battery needs to be recharged.
Battery runs out quickly - Battery needs to be serviced or replaced.
Disconnected battery cables or bad terminals - Check wiring and clean or replace terminals.

Starter is not cranking
Battery is drained or defective - Recharge or change battery.
Wiring is improperly connected or disconnected - Check wiring and connect properly.
Low battery output voltage - Charge the battery.
Starter motor is defective - Replace or repair starter.

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WHEEL LOADERS SPECIFICATIONS

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