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| Home / Wheel Loaders / Hitachi Wheel Loaders / Hitachi ZW120-6 |
Hitachi ZW120-6 Troubleshooting
The
Hitachi ZW120-6 wheel loader driveline system components: Deutz TCD3.6L4F
four-stroke four-cylinder vertical in-line turbocharged liquid-cooled diesel
engine with a rated power of 96 hp (71 kW), and 2-speed hydrostatic transmission
with powershift gearbox. The hydraulic system has a pump with a rated capacity
of 32 gal/min (121 l/min). The Hitachi ZW120-6 is equipped with a hydraulic
power steering, boom floating system, and 17.5x25 tires. The wheel loader has a
maximum lift height to hinge pin of 140.1" (3560 mm) and boom breakout force of
16840 lbs (7655 kg). The rated operating capacity is 6195 lbs (2810 kg), and
tipping load is 12390 lbs (5620 kg).
| Engine Troubleshooting |
Engine difficult to start or will not start
There is air in the fuel system - Bleed the system.
Fuel filter plugged - Replace the filter element.
Fuel injection nozzles are damaged or dirty - Test injection nozzles and change if necessary.
Water or dirt in fuel system - Drain, flush, and service the system.
Incorrect valve clearance - Need to adjust valve clearance.
Fuel injection pump is damaged - Rebuild or install a new injection pump.
Diesel starts but immediately shuts off
Air cleaner is dirty - Clean or replace element.
Dirty fuel filter - Clean the filter or install new filter element.
Fuel injection pump has loose connections - Tighten the connections.
Damaged or clogged injectors - Change or clean fuel injectors.
Fuel injection pump is damaged - Repair or install a new fuel pump.
Engine stalls after running
Coolant temperature is low - Warm up to required temperature.
Fuel filter element clogging - Replace filter element.
Air in the fuel pipes - Bleed the fuel pipes.
Fuel injection nozzles are damaged or dirty - Install a new kit of correctly balanced nozzles.
Improper setting of fuel injection pump timing - Adjust the pump as required.
Engine stalling at idle
Improperly adjusted low idle speed - Test and adjust.
Fuel injection pump malfunctioning - Repair or change injection pump.
Defective fuel injectors - Change or clean fuel injectors.
Incorrect valve clearance - Adjustment procedure required.
Engine power loss
Air filter is plugged - Clean or replace element.
Fuel injection nozzles fault - Change fuel injection nozzles.
Fuel injection pressure is incorrect - Correct the pressure settings.
Valve clearance is out of adjustment - Check and adjust.
Low idle speed adjustment is incorrect - Adjustment required.
Fuel hoses or lines clogging - Clean fuel system lines and hoses.
Worn cylinder head gasket - Change cylinder head gasket.
Piston rings are worn or defective - Replace piston rings.
Engine overheating
Engine coolant is insufficient - Fill radiator to proper level and check components for faults.
Insufficient engine oil - Need to add engine oil.
Defective radiator cap or clogged radiator core - Change cap or clean radiator.
Broken or loose fan belt - If necessary, replace the belt.
Engine overloaded - Load reducing required.
Oil pressure is insufficient
Insufficient engine oil - Add oil to the engine crankcase.
Oil filter is dirty - Replace or service engine oil filter.
Wrong oil viscosity - Use proper viscosity oil.
Crankshaft bearing oil clearance is incorrect - Bearing replacement required.
Oil pump failure - Check and replace if necessary.
Engine knocking or noise
Lack of engine oil - Check oil level and add oil as required.
Engine is cold - Normalize the temperature by warming up the engine.
Wrong setting of fuel injection pump timing - Set up as recommended.
Too low idle RPM - Adjustment required.
Fuel injectors are faulty or clogged - Clean fuel injectors or change it.
Connecting rod misalignment or failure - Need to change or align the connecting rod.
Pistons are worn or broken - Replace the pistons.
| Transmission Troubleshooting |
Transmission fluid pressure is insufficient
Lack of transmission fluid - Need to add transmission fluid.
Transmission oil filter element clogging (if equipped) - Clean or change transmission oil filter.
Relief valve is damaged - Replace valve as required.
Transmission makes excessive noise
Transmission oil insufficient - Need to add transmission oil.
Transmission fluid contamination - Fill up with fresh transmission fluid.
Gears are defective or backlash is improper - Adjust backlash properly or replace the gears.
Worn or broken bearings - Change faulty bearings.
Damaged or worn gear shift forks - Replace defective shift forks.
Shaft splines are damaged or worn - Replace defective shaft.
Hard to shift gears
Corroded or worn gear shift linkage - Lubricate or replace the shift linkage.
Worn or bent shift forks - Install new shift forks.
Worn gear shifting mechanism - Repair or change worn components if necessary.
Worn or unadjusted clutch - Replace or adjust clutch.
External oil leaks
Too much oil in transmission - Drain the excess oil.
Damaged gaskets or seals - Gaskets or seal need to be replaced.
| Hydraulics Troubleshooting |
Hydraulic system overheats
Incorrect hydraulic pressure setting - Correct setting is required.
Faulty or improperly adjusted main relief valve - Adjust or replace the relief valve.
Hydraulic oil is contaminated - The oil must be changed.
Hydraulic fluid level is insufficient - Fill the hydraulic system with oil.
Worn hydraulic oil pump - Repair or change pump if required.
Boom fails to lift or drop
Faulty lift controls - Change or repair.
Hydraulic pump malfunction - Repair or replace pump if necessary.
Defective hydraulic control valve - Change or repair hydraulic valve.
Faulty hydraulic cylinder - Repair or change hydraulic cylinder.
Low hydraulic fluid level - Fill up the hydraulic fluid.
Bucket does not tilt
Defective bucket controls - Replace or repair.
Hydraulic pump is broken - Install new pump or repair it.
Hydraulic control valve malfunction - Repair or change hydraulic valve.
Defective bucket cylinder - Change or repair cylinder.
Hydraulic oil is insufficient - Checking hydraulic oil level and add if necessary.
Bucket or lift arm functions slowly
Worn hydraulic oil pump - Test the pump flow rate and change pump if required.
Hydraulic cylinder leaking - Cylinder seals need to be replaced.
Low hydraulic oil level - Checking hydraulic oil level and add if necessary.
Hydraulic control valve is defective or set improper - Adjust correctly or repair.
Hydraulic system loosing pressure - Correct setting is required.
Bucket or boom is jerky
Air trapped in hydraulic system - Bleed air from system.
Plugged hydraulic oil filter - Clean or change the filter.
Hydraulic fluid is contaminated - Fill up with fresh hydraulic fluid.
Cylinder tube or rod is scored - Change defective component.
Hydraulic pump is excessively noisy
Not enough oil or hydraulic system leaking - Top up hydraulic oil or remedy leakage in system.
Hydraulic filter is dirty - Service or replace hydraulic filter.
Suction line clogging - Service the suction line.
Air enters the pump - Air bleeding is required.
Pump parts are faulty - Rebuild or replace hydraulic pump.
| Electrical Troubleshooting |
Battery is not charging
Wiring connections are loose or corroded - Tighten or clean electrical wiring connections.
Faulty battery terminal clamps - Install new terminal clamps.
Battery dead cell - Use a new battery.
Belt is damaged or loose - Adjust belt tension or replace belt.
Starter turns slow
Low battery voltage - Battery is drained, charge it.
Battery runs out quickly - Service battery or replace it.
Battery terminals are corroded or wires are disconnected - Check cables and clean or change terminals.
Starter will not crank
Battery is low or faulty - Recharge or change battery.
Wire harness is disconnected or incorrectly connected - Check wire harness and connect as required.
Low battery power - Low battery charging, charge as required.
Starter motor failure - Starter needs to be replaced.
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| WHEEL LOADERS SPECIFICATIONS |
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