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Home / Wheel Loaders / Hitachi Wheel Loaders / Hitachi ZW50

Hitachi ZW50 Troubleshooting

The Hitachi ZW50 wheel loader is powered by 148.5 cu.in (2.4L) Kubota V2403-M-DI 4-cycle vertical 4-cylinder naturally aspirated liquid-cooled diesel engine with a rated power of 46 hp (34.1 kW) at 2400 rpm. The Hitachi ZW50 is equipped with a two-speed hydrostatic transmission, hydraulic power steering, boom floating system, and 15.5/60-18 standard tires. The hydraulic system has a gear pump with fluid flow rate of 12.8 gpm (48.3 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" (3140 mm) to hinge pin, and bucket breakout force is 5620 lbs (2555 kg).

Engine Troubleshooting

Engine starts hard or will not start
Air trapped in fuel system - Bleed air.
Dirty fuel filter - Change filter element.
Clogged or burnt injection nozzle - Change fuel injection nozzles.
Water in the fuel system - Change fuel and repair fuel system.
Excessive valve clearance - Check and adjust as required.
Fuel injection pump is not operating properly - Install a new pump or rebuild.

Diesel starts and stops
Air filter is dirty - Install new air filter element.
Fuel filter plugging - Service or replace the filter.
Fuel injection pump has loose connections - Tighten the connections.
Dirty or defective injectors - Replace or clean fuel injectors.
Damaged fuel injection pump - Install a new pump or rebuild.

Engine stalls after running
Engine is not fully warmed up - Warm up the engine.
Dirty fuel filter - Change filter element.
There is air in the fuel system - Bleed the system.
Defective or clogged injection nozzle - Service or change injection nozzles.
Fuel injection pump timing is not adjusted - Set it up as required.

Engine stops when idle
Incorrect low idle setting - Normalize low idle speed.
Faulty fuel injection pump - Repair or install a new fuel pump.
Dirty or defective injectors - Replace or clean fuel injectors.
Valve clearance is not correct - Adjust valve clearance.

Diesel engine loses power
Air filter is clogged - Clean or replace element.
Defective or clogged injection nozzle - If necessary, replace with a new nozzle.
Fuel injection pressure is incorrect - Adjust to correct pressure.
Valve clearance is wrong - Adjust to proper valve clearance.
Low idle speed adjustment is incorrect - Normalize low idle speed.
Clogged fuel lines or hoses - Fuel lines and hoses need to be cleaned.
Damaged cylinder-head gasket - Install a new gasket.
Leaking or damaged piston rings - Change piston rings.

Engine is overheated
Lack of engine coolant - Fill the cooling system and check components for leaks or other faults.
Engine oil level is low - Need to add engine oil.
Dirty radiator fins or defective radiator cap - Replace cap or clean radiator.
Loose or damaged fan belt - The fan belt needs to be replaced.
Diesel engine overloaded - Load reducing is recommended.

Oil pressure is low
Low oil level - Add oil as required.
Dirty oil filter - Change or clean engine oil filter element.
Improper type of engine oil - Use oil of proper viscosity.
Crankshaft bearing oil clearance is incorrect - Change bearings.
Oil pump malfunction - Remove and inspect oil pump.

Engine noises or knocks
Lack of engine oil - Check and refill engine oil.
Coolant temperature is low - Warm up to required temperature.
Wrong setting of fuel injection pump timing - Set up as recommended.
Low idle speed set incorrectly - Adjust the low idle speed.
Dirty or defective injectors - Clean or replace fuel injectors.
Connecting rod is worn or misaligned - Connecting rod must be aligned or replaced.
Worn or scored pistons - Replace the pistons.

Hydrostatic Transmission Troubleshooting

Hydrostatic transmission noises
Oil is dirty or oil level is too low - Add oil to proper level or pour fresh transmission oil.
Bent or unadjusted speed control pedal linkage - Adjust or replace linkage.
Defective relief valve - Replace relief valve.
Transmission overload - The load should be reduced.
Worn or defective transmission components - After disassembling and inspection, change defective components.

Power is too low
Transmission oil level is low - Fill the transmission housing to proper oil level.
Relief valve failure - Replace relief valve.
Bent or unadjusted speed control pedal linkage - Adjust or install new linkage.

Transmission fluid over heats
Low fluid level - Checking transmission fluid level and add if necessary.
Dirty transmission fluid filter - Service or change transmission fluid filter.
Defective or plugged cooling components - Inspect all cooling components and replace or repair if necessary.
Excessive transmission load - Reduce loading.

Transmission fluid leakage
Worn seals or gaskets - Seals and gaskets need to be replaced.
Internal transmission housing pressure is too high - Replace worn components.
Clogged transmission fluid return tube - Clean or replace return tube.

Hydraulics Troubleshooting

Hydraulic system overheated
Hydraulic pressure is not adjusted correctly - Correct adjustment is required.
Faulty or improperly adjusted main relief valve - Adjust or change relief valve.
Dirty hydraulic oil - Change hydraulic oil.
Not enough hydraulic fluid in the system - Add fluid to the hydraulic system.
Faulty hydraulic oil pump - Replace or repair pump if necessary.

Lift arm fails to drop or lift
Lift controls failure - Replace or repair.
Hydraulic pump failure - Replace or repair pump if necessary.
Damaged hydraulic control valve - Repair or replace the valve.
Defective hydraulic cylinder - Repair or replace hydraulic cylinder.
Hydraulic fluid is insufficient - Add fluid as required.

Bucket is not working
Bucket tilt controls malfunction - Repair or change.
Damaged hydraulic oil pump - Repair or change pump if required.
Hydraulic control valve malfunction - Install a new valve or repair it.
Damaged bucket cylinder - Install a new cylinder or repair it.
Insufficient hydraulic oil - Checking hydraulic oil level and add if necessary.

Slow boom or bucket action
Faulty hydraulic oil pump - Check pump flow and install new pump if necessary.
Oil leaks from hydraulic cylinder - Change cylinder piston seals.
Low hydraulic fluid level - Add fluid as required.
Hydraulic control valve is defective or set improper - Repair or adjust properly.
Hydraulic pressure loss - Hydraulic pressure must be set correctly.

Jerky operation of the bucket or boom
Air trapped in hydraulic system - Air bleeding is required.
Hydraulic oil filter element is dirty - Clean or install new filter.
Hydraulic oil is dirty - Hydraulic oil change required.
Cylinder rod or tube is scuffed - Change worn component.

Hydraulic pump makes excessive noise
Hydraulic leaks or low oil level - Add hydraulic oil or correct system leaks.
Dirty hydraulic filter - Clean or change the filter.
Plugged suction line - Service the suction line.
Air in hydraulic pump - Air bleeding is required.
Pump parts are damaged - Rebuild or change hydraulic pump.

Electrical Troubleshooting

Battery cannot be charged
Wiring connections are loose or corroded - Clean or tighten connections.
Defective electrical terminal connectors - Replace terminal connectors.
Battery faulty cell - Install a new battery.
Loose or worn belt - Install a new belt or adjust belt tension.

Starter motor turns slow
Low battery voltage - Recharge the battery.
Battery drains quickly - Service or change the battery.
Terminals are faulty or battery cables are disconnected - Check cable connections and change or clean terminals.

Starter motor won't turn
Battery is drained or worn - Charge or replace the battery.
Wiring is improperly connected or disconnected - Check wiring and connect properly.
Low battery output voltage - Low battery charging, charge as required.
Faulty starter motor - Repair or replace starter.

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WHEEL LOADERS SPECIFICATIONS

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