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Home / Wheel Loaders / John Deere Wheel Loaders / John Deere 344H

John Deere 344H Troubleshooting

The John Deere 344H wheel loader driveline system components: 276 cu.in (4.5L) John Deere PowerTech 4045T 4-cylinder direct injection turbocharged diesel engine with a rated power of 98 hp (73 kW), and 2-range hydrostatic transmission. The hydraulic system has a gear pump with a rated capacity of 30.3 gal/min (115 l/min). The John Deere 344H is equipped with a power steering system, hydraulic dual disc brakes, and 17.5x25 standard tires. The wheel loader has a maximum lift height to hinge pin of 143.5" (3645 mm) and boom breakout force of 16630 lbs (7545 kg). The rated operating capacity is 5505 lbs (2495 kg), and tipping load is 11010 lbs (4990 kg).

Engine Troubleshooting

Engine starts up hard or will not start
Air trapped in fuel system - Bleed air.
Fuel filter element is dirty - Replace the filter element.
Fuel injection nozzles are damaged - Check injection nozzles and replace if required.
Water or dirt in fuel system - Drain, flush, and service the system.
Valve clearance is out of adjustment - Adjust valve clearance.
Fuel injection pump failure - Repair or replace injection pump.

Engine starts and stops suddenly
Air cleaner is clogged - Clean or change.
Fuel filter plugging - Replace filter element.
Poor fuel injection pump tightness - Look for any leaks of fuel pump, tighten it fast.
Dirty or defective injectors - Test and replace fuel injectors if necessary.
Fuel injection pump failure - Install a new pump or rebuild.

Engine stalls during operation
Engine is not preheated - Warm up to required temperature.
Fuel filter element is dirty - Clean or change the filter.
There is air in the fuel system - Bleed the system.
Fuel injection nozzles are faulty or clogged - Service or change injection nozzles.
Improper fuel injection timing - Set the fuel pump timing correctly.

Engine shuts off while idling
Low idle speed setting is incorrect - Adjust low idling as recommended.
Fuel injection pump is not operating properly - Replace or rebuild injection pump.
Fuel injector fault - Clean fuel injectors or change it.
Improper valve clearance - Adjust valve clearance.

Diesel engine is losing power
Plugged air filter - Clean or replace element.
Fuel injection nozzles are faulty or clogged - Service or change injection nozzles.
Incorrect fuel injection pressure - Adjust pressure to proper level.
Valve clearance is not correct - Adjustment procedure required.
Low idle speed adjustment is incorrect - Adjust low idling as recommended.
Clogged fuel hoses or lines - Clean fuel system lines and hoses.
Damaged cylinder-head gasket - Install a new gasket.
Leaking or defective piston rings - Change piston rings.

Engine overheated
Insufficient coolant fluid - Fill the cooling system and check components for leaks or other faults.
Engine oil insufficient - Fill up the oil to required level.
Dirty radiator core or faulty radiator cap - Install new cap or clean radiator.
Damaged or worn fan belt - Belt replacement is recommended.
Engine is under excessive load - Reduce load on the engine.

Oil pressure is insufficient
Low crankcase oil level - Add oil as required.
Dirty oil filter element - Clean or change engine oil filter.
Wrong oil viscosity - Use correct viscosity oil.
Incorrect crankshaft bearing oil clearance - Install new bearings.
Oil pump malfunction - Repair or change.

Engine knocks or noises
Engine oil insufficient - Add oil to the engine crankcase.
Engine is not warmed up to required temperature - Warm up engine as required.
Fuel injection pump timing is not adjusted - Set up as recommended.
Too low idle RPM - Adjust low idle speed.
Fuel injector fault - Clean or replace fuel injectors.
Misaligned or defective connecting rod - Alignment procedure or replacement is required.
Scored or worn pistons - Pistons replacement required.

Hydrostatic Transmission Troubleshooting

HST transmission is excessively noisy
Transmission fluid is dirty or fluid level is too low - Fill to required level or change the fluid.
Bent or unadjusted speed control pedal linkage - Adjust or repair linkage.
Defective relief valve - Change the valve.
Excessive loading - Reduce loading.
Defective or worn transmission parts - Check hydrostatic transmission components for defect or damage and change if necessary.

Loss of power
Lack of transmission fluid - Checking transmission fluid level and add if necessary.
Relief valve failure - Replace relief valve as required.
Speed control linkage is defective or unadjusted - Adjust or replace linkage.

Transmission fluid over heats
Lack of transmission oil supply - Fill up the transmission oil.
Plugged transmission oil filter - Clean or replace the transmission filter.
Defective or plugged cooling components - Inspect all cooling components and replace or repair if necessary.
Excessive loading - Reduce loading.

Transmission fluid leakage
Broken seals or gaskets - Seals and gaskets need to be replaced.
High internal transmission case pressure - Check hydrostatic transmission components for defect or damage and change if necessary.
Plugged transmission fluid return tube - Service or replace return tube.

Hydraulics Troubleshooting

Hydraulic system is overheated
Incorrect hydraulic pressure setting - Set pressure correctly.
Main relief valve is damaged or adjusted improperly - Adjust the valve or replace if necessary.
Dirty hydraulic oil - The oil must be changed.
Hydraulic fluid level is insufficient - Add fluid to the hydraulic system.
Worn hydraulic oil pump - Repair or install new hydraulic pump.

Boom cannot be lowered or raised
Lift controls are defective - Repair or change.
Hydraulic pump is broken - Repair or replace pump if necessary.
Hydraulic control valve failure - Replace or repair the valve.
Faulty hydraulic cylinder - Change or repair lift cylinder.
Low hydraulic oil level - Checking hydraulic oil level and add if necessary.

Bucket fails to tilt
Bucket controls are faulty - Replace or repair.
Hydraulic pump malfunction - Repair or replace pump if necessary.
Hydraulic control valve malfunction - Replace or repair the valve.
Defective bucket cylinder - Install a new cylinder or repair it.
Low hydraulic oil level - Need to add oil.

Bucket or lift arm moves slowly
Hydraulic pump is defective - Check pump performance and change it if necessary.
Leaking hydraulic cylinder - Cylinder seals need to be replaced.
Hydraulic oil level low - Checking hydraulic oil level and add if necessary.
Hydraulic control valve is defective or set improper - Set properly or repair.
Hydraulic pressure loss - Correct adjustment is required.

Bucket or boom is jerky
Hydraulic system is leaking air - Bleed air from system.
Hydraulic oil filter element clogging - Service or replace the hydraulic filter.
Hydraulic fluid is contaminated - Fill up with fresh hydraulic fluid.
Cylinder rod or tube is scuffed - Change failed component.

Hydraulic pump makes excessive noise
Not enough oil or hydraulic system leaking - Remedy hydraulic leakage or refill oil as necessary.
Hydraulic filter is dirty - Clean or install new filter.
Plugged suction line - Need to service the suction line.
Air in hydraulic pump - Remove air from hydraulics.
Damaged pump parts - Rebuild or replace hydraulic pump.

Electrical Troubleshooting

Battery does not charge
Wiring connections are corroded or loose - Clean or tighten connections.
Faulty battery terminal connectors - Change terminal connectors.
Dead cell in battery - Install a new battery.
Defective or loose belt - Install a new belt or adjust belt tension.

Starter motor cranks slow
Low battery power - Recharge the battery.
Battery won’t hold charge - Service charging system or change battery.
Disconnected wires or corroded battery terminals - Connect wiring properly or install new terminals.

Starter is not cranking
Battery is discharged or worn - Charge or change the battery.
Battery wires are disconnected or incorrectly connected - Check wires and connect correctly.
Low battery output voltage - Battery needs to be recharged.
Starter motor is defective - Starter needs to be changed.

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WHEEL LOADERS SPECIFICATIONS

Wheel Loaders, Skid Steers, and Compact Track Loaders