Caterpillar 279D3 Track Loader Troubleshooting

The Caterpillar 279D3 compact track loader is powered by 203.1 cu.in (3.3L) Cat C3.3B DIT 4-cylinder turbocharged diesel engine with a rated power of 72.9 hp (54.4 kW). The Caterpillar 279D3 is equipped with a 2-speed transmission, radial-lift loader boom, and steel embedded rubber tracks. The hydraulic system has standard or HF XPS pump with fluid flow rate of 23 gpm (86 lpm) or 32 gpm (121 lpm). The hydraulic pressure is 3335 psi (230 bar) or 4060 psi (280 bar). The track loader has a rated operating capacity of 2220 lbs (1010 kg) and tipping load of 6340 lbs (2890 kg). The lift height is 124.9" (3175 mm) to hinge pin, and dump height is 97.8" (2485 mm).

Engine Troubleshooting

Engine difficult to start or will not start

Air in fuel tank - Bleed fuel tank.
Clogged fuel filter - Replace filter element.
Dirty or faulty injection nozzles - Inspect nozzles and replace if necessary.
Water or dirt in fuel system - Drain, flush, and service the system.
The valve clearance is not adjusted - Adjust to proper valve clearance.
Fuel injection pump malfunctioning - Replace or rebuild injection pump.

Diesel starts and stops

Dirty air cleaner - Service or replace air cleaner.
Fuel filter element is dirty - Install new filter element.
Poor fuel injection pump tightness - Look for any leaks of fuel pump, tighten it fast.
Dirty or defective injectors - Inspect fuel injectors and change as required.
Defective fuel injection pump - Replace injection pump or repair it.

Engine stalls while running

Coolant temperature is low - Warm up the engine.
Fuel filter element is dirty - Clean or change the filter.
Air in fuel tank - Bleed fuel tank.
Faulty fuel injection nozzles - Inspect nozzles and replace if necessary.
Incorrect adjustment of fuel injection pump timing - Adjust the pump as required.

Engine stops while idle

Incorrect low idle speed adjustment - Correct low idle adjustment.
Fuel injection pump malfunctioning - Repair or change injection pump.
Fuel injector fault - Replace fuel injectors.
Excessive valve clearance - Check and adjust as required.

Loss of engine power

Air cleaner is dirty - Install new air cleaner element.
Defective injection nozzle - Check and replace nozzles if required.
Insufficient fuel injection pressure - Adjust pressure to proper level.
The valve clearance is incorrect - Adjust valve clearance.
Improperly adjusted low idle speed - Correct the settings.
Dirt in the fuel lines or hoses - Fuel lines and hoses need to be cleaned.
Damaged cylinder-head gasket - Install a new gasket.
Defective or worn piston rings - Replace piston rings.

Engine overheating

Lack of coolant in cooling system - The cooling system needs to be refilled and checked for faults.
Not enough engine oil - Add oil to the engine crankcase.
Damaged radiator cap or dirty radiator core - Clean radiator or replace cap.
Fan belt is loose or defective - The fan belt needs to be replaced.
Diesel engine overloaded - Load reducing is recommended.

Oil pressure too low

Engine oil insufficient - Fill up the engine oil.
Dirty oil filter element - Replace or service engine oil filter.
Oil grade or viscosity is wrong - Drain crankcase and refill with correct oil.
Incorrect oil clearance in main bearing - Bearing replacement required.
Oil pump failure - Replace as required.

Engine knocking sound or abnormal noise

Engine oil level low - Fill the crankcase with engine oil.
Engine is not fully warmed up - Warm up the engine.
Fuel injection pump timing is not adjusted - Use the correct fuel injection pump timing adjustment.
Low idle speed adjustment is incorrect - Adjust as required.
Dirty or defective injectors - Replace fuel injectors.
Connecting rod is misaligned or defective - Align or replace connecting rod.
Piston wear or scoring - Pistons replacement required.

Drive System Troubleshooting

Drive system does not work in either direction

Hydraulic oil level is low - Need to add oil.
Defective or blocked track mechanism - Correct blockage or repair tracks.
Relief valve is damaged or worn - Repair or replace relief valve.
Hydraulic filter or suction line is dirty - Check, clean, or change if necessary.
Defective or worn foot or hand controls - Replace or repair.
Defective drive pump or motor - Check and repair if required.

Machine does not drive straight or drives jerky

Track mechanism is defective or jammed - Remove jamming or repair tracks.
Tracks are sagging or faulty - Repair tracks or correct track sag with tension.
Debris, dirt, or foreign objects jammed in undercarriage track frame - Remove debris or foreign objects and clean track frame.

Power is too low

Hydraulic oil filter is plugged - Replace or clean hydraulic filter.
Faulty or opened relief valve - Close or replace relief valve.
Transmission parts are worn or defective - Check and replace defective components.
Damaged input drive shaft - Rebuild or change the shaft.
Hydraulic system is leaking air - Bleed air from system.

Overheated drive system

Low hydraulic oil level - Fill the system to proper hydraulic oil level.
Hydraulic fluid filter is plugged - Change hydraulic filter.
Defective relief valve - Repair or replace relief valve.
Defective drive pump or hydraulic motor - Repair or replace faulty component.
Hydraulic oil cooler is plugged - Clean cooling fins as required.
Drive system overloaded continuously - Load needs to be reduced.

Drive system is noisy

Improper oil viscosity - Use oil of proper viscosity.
Air trapped in hydraulic system - Air bleeding is required.
Worn hydraulic motor or drive pump - Repair or replace faulty component.
Defective or worn mechanical parts of drive system - Inspect the components for worn or defect and repair as required.

Hydraulics Troubleshooting

Hydraulic system overheats

Hydraulic pressure incorrectly adjusted - Adjust pressure correctly.
Main relief valve is defective or unadjusted - Adjust or replace the relief valve.
Hydraulic fluid is contaminated - Hydraulic fluid change required.
Hydraulic fluid level is insufficient - Need to add fluid.
Hydraulic pump is defective - Repair or replace pump if necessary.

Boom fails to lift or drop

Damaged lift controls - Repair or replace.
Damaged hydraulic oil pump - Replace or repair pump if necessary.
Hydraulic control valve malfunction - Repair or change hydraulic valve.
Defective hydraulic cylinder - Repair or install a new lift cylinder.
Low hydraulic fluid level - Checking hydraulic fluid level and add if necessary.

Bucket fails to tilt

Bucket controls failure - Repair or change.
Hydraulic pump is broken - Install new pump or repair it.
Damaged hydraulic control valve - Repair or change the valve.
Broken bucket cylinder - Repair or change cylinder.
Hydraulic oil level low - Check and refill the hydraulic oil.

Boom or bucket is moving slowly

Hydraulic pump is worn - Check pump flow and change pump if necessary.
Leaking hydraulic cylinder - Correct leakage by changing the seals.
Hydraulic oil level low - Fill the system to proper hydraulic oil level.
Defective or not adjusted hydraulic control valve - Repair or set properly.
Hydraulic pressure has dropped - Hydraulic pressure must be set correctly.

Bucket or boom is jerky

Air in the hydraulic system - Air bleeding is required.
Hydraulic oil filter clogging - Clean or install new filter.
Hydraulic fluid contamination - Change hydraulic fluid.
Cylinder rod or tube is scuffed - Change failed component.

Hydraulic pump makes excessive noise

Insufficient oil level or leaking hydraulic system - Remedy hydraulic leakage or refill oil as necessary.
Plugged hydraulic filter - Change or clean oil filter.
Suction line is clogged - Service the suction line.
Pump is sucking air - Bleed air.
Faulty pump components - Rebuild or change hydraulic pump.

Electrical Troubleshooting

Battery is not charging

Corroded or loose wire connections - Tighten or service connections.
Defective battery terminal clamps - Install new terminal clamps.
Battery is defective - Install a new battery.
Defective or loose belt - Belt needs to be adjusted or changed.

Starter cranks slowly

Battery voltage is low - Charge the battery.
Battery will not hold charge - Service charging system or install new battery.
Bad battery terminals or disconnected wiring - Connect wires correctly or change terminals.

Starter will not crank

Battery is discharged or defective - Change or recharge battery.
Disconnected or improperly connected wiring harness - Inspect battery wiring harness and connect as required.
Low battery output voltage - Battery is drained, charge it.
Defective starter motor - Repair or install a new starter.