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John Deere 444J Troubleshooting
The
John Deere 444J wheel loader is powered by 276 cu.in (4.5L) John Deere PowerTech
4045H vertical 4-cylinder turbocharged liquid-cooled diesel engine with a rated
power of 115 hp (82 kW) at 2200 rpm. The John Deere 444J is equipped with a 4x3
powershift transmission, power steering system, hydraulic wet multi-disc brakes,
and 20.5R25 standard tires. The hydraulic system has a pump with fluid flow rate
of 36.9 gpm (140 lpm). The wheel loader has a rated operating capacity of 7820
lbs (3545 kg) and tipping load of 15640 lbs (7090 kg). The max lift height is
141.5 inches (3595 mm) to hinge pin, and boom breakout force is 18100 lbs (8210
kg).
| Engine Troubleshooting |
Engine starts hard or doesn't start
Air in the fuel pipes - Bleed the fuel pipes.
Fuel filter plugged - Change filter element.
Dirty or faulty 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 - Adjust valve clearance.
Fuel injection pump is defective - Install a new pump or rebuild.
Engine starts and stalls suddenly
Dirty air cleaner - Service or replace air cleaner.
Fuel filter plugged - Change filter element.
Fuel injection pump is leaking - Repair any leaks.
Dirty or defective injectors - Replace fuel injectors.
Fuel injection pump failure - Repair or install new pump.
Engine shuts off suddenly while running
Low coolant temperature - Normalize the temperature by warming up the engine.
Fuel filter is plugged - Service or replace the filter.
Air in fuel system - Bleed fuel system.
Fuel injection nozzles fault - Clean or change injection nozzles.
Improper fuel injection timing - Adjust fuel injection pump as required.
Engine stalls when idling
Incorrect low idle speed adjustment - Adjust the low idle speed.
Fuel injection pump malfunctioning - Replace injection pump or repair it.
Clogged or defective injectors - Test and replace fuel injectors if necessary.
Valve clearance is out of adjustment - Have it adjusted.
Lack of engine power
Air cleaner is dirty - Clean or replace air cleaner element.
Fuel injection nozzles are clogged or faulty - Clean or change injection nozzles.
Fuel injection pressure is wrong - Adjust to correct pressure.
Valve clearance is not correct - Correct valve clearance.
Incorrectly set low idle speed - Adjust low idling as recommended.
Fuel lines or hoses are dirty - Clean fuel system hoses and lines.
Cylinder head gasket is defective - Change cylinder head gasket.
Piston rings are leaking or defective - Piston rings replacement required.
Engine overheats
Lack of engine coolant - Top up coolant fluid and check system for leaks.
Engine oil level low - Checking oil level and add if necessary.
Radiator core is dirty or radiator cap is damaged - Clean radiator or install new cap.
Fan belt is worn or faulty - If necessary, replace the belt.
Engine overload - Load reducing is recommended.
Oil pressure too low
Not enough oil in the engine - Checking oil level and add if necessary.
Dirty oil filter - Replace or service engine oil filter.
Wrong oil viscosity - Drain crankcase and refill with correct oil.
Excessive oil clearance of crankshaft bearing - Bearings need to be reinstalled.
Defective oil pump - Remove and inspect oil pump.
Abnormal engine noise or knocking
Low engine oil level - Need to add engine oil.
Engine not warmed up - Warm up the engine.
Improper setting of fuel injection pump timing - Check the fuel injection pump timing adjustment.
Low idle speed set incorrectly - Adjust the low idle speed.
Dirty or defective injectors - Inspect fuel injectors and change as required.
Misaligned or defective connecting rod - Alignment procedure or replacement is required.
Worn or scored pistons - Have pistons replaced.
| Transmission Troubleshooting |
Transmission oil pressure is insufficient
Transmission oil level is low - Fill up the transmission oil.
Transmission oil filter is dirty (if equipped) - Clean or replace the transmission filter.
Relief valve failure - Replace valve as required.
Excessive transmission noise
Insufficient transmission oil - Need to add transmission oil.
Transmission fluid is dirty - Transmission fluid change required.
Defective gears or improper backlash - Adjust backlash correctly or replace the gears.
Bearings are broken or worn - Bearings replacement required.
Worn or damaged gear shift forks - Change the shift forks.
Worn or stuck shaft splines - Shaft need to be replaced.
Gear hard to shift
Stuck or worn gear shift linkage - Install new shift linkage.
Shift forks are worn or bent - Replace defective shift forks.
Worn gear shifting mechanism - Repair or change worn components if necessary.
Worn or unadjusted clutch - Adjust or change the clutch.
Transmission oil leaking
Too much fluid in transmission - Excess fluid must be drained.
Damaged gaskets or seals - Seals and gaskets need to be replaced.
| Hydraulics Troubleshooting |
Hydraulic system overheating
Hydraulic pressure incorrectly adjusted - Adjust it correctly.
Defective or misadjusted main relief valve - Adjust or change relief valve.
Contaminated hydraulic oil - The oil must be changed.
Hydraulic oil level is insufficient - Add oil to the hydraulic system.
Defective hydraulic pump - Change or repair hydraulic pump if required.
Lift arm can't drop or lift
Damaged lift controls - Change or repair.
Hydraulic pump is broken - Repair or change pump if required.
Defective hydraulic control valve - Change or repair hydraulic valve.
Hydraulic cylinder failure - Replace or repair boom cylinder.
Hydraulic fluid is insufficient - Checking hydraulic fluid level and add if necessary.
Bucket does not tilt
Bucket controls failure - Change or repair.
Damaged hydraulic oil pump - Repair or replace pump if necessary.
Hydraulic control valve malfunction - Repair or replace the valve.
Hydraulic bucket cylinder is defective - Replace or repair cylinder.
Hydraulic oil is insufficient - Check and refill the hydraulic oil.
Slow bucket or lift arm operation
Worn hydraulic oil pump - Check hydraulic pump flow and replace pump if necessary.
Oil leaks from hydraulic cylinder - Replace cylinder piston seals.
Low hydraulic oil level - Need to add oil.
Worn or unadjusted hydraulic control valve - Adjust properly or repair.
Hydraulic pressure loss - Correct adjustment is required.
Bucket or boom movements are jerky
There is air in the hydraulic system - Bleed air from hydraulic system.
Plugged hydraulic oil filter - Service or replace the hydraulic filter.
Hydraulic oil contamination - Hydraulic oil change required.
Cylinder rod or tube is scratched - Replace damaged component.
Hydraulic pump is noisy
Not enough oil or hydraulic system leaking - Remedy hydraulic leakage or refill oil as necessary.
Hydraulic filter clogging - Service or change hydraulic filter.
Suction line is dirty - Clean suction line as required.
Pump is sucking air - Remove air from hydraulics.
Damaged pump components - Rebuild or install new pump.
| Electrical Troubleshooting |
Battery won’t charge
Electrical cable connections are corroded or loose - Tighten or service cable connections.
Electrical terminal connectors are faulty - Install new terminal connectors.
Battery is worn - Install a new battery.
Belt is damaged or loose - Change belt or adjust belt tension.
Starter turning slow
Low battery voltage - Low battery charging, charge as required.
Battery runs out quickly - Service battery or change it.
Faulty battery terminals or disconnected cables - Connect cables correctly or replace terminals.
Starter motor won't turn
Battery is drained or worn - Replace or charge as required.
Battery wiring is disconnected or improperly connected - Inspect wiring and connect as required.
Battery voltage is low - Charge the battery.
Damaged starter motor - Starter should be changed.
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| WHEEL LOADERS SPECIFICATIONS |
Bobcat
Caterpillar
Case
Doosan
John Deere
Kubota