Caterpillar 279D Track Loader Troubleshooting

The Cat 279D 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 71.8 hp (53.6 kW). The Caterpillar 279D is equipped with a two-speed hydrostatic transmission, radial-lift loader boom, fully suspension undercarriage, and 15.7" (400 mm) or 17.7" (450 mm) rubber tracks. The hydraulic system has a high flow XPS pump with fluid flow rate of 32 gpm (121 lpm). The hydraulic pressure is 4060 psi (280 bar). The loader has a rated operating capacity of 2055 lbs (932 kg) and tipping load of 5870 lbs (2660 kg). The lift height is 124.9" (3.18 m) to hinge pin, and dump height is 97.8" (2.49 m).

Engine Troubleshooting

Engine difficult to start or won't start

Air in fuel system - Bleed fuel system.
Fuel filter plugging - Service or replace the filter.
Fuel injection nozzles are dirty or defective - Service or change injection nozzles.
Water or dirt in fuel system - Drain, flush, and service the system.
Valve clearance is wrong - Adjustment procedure required.
Fuel injection pump failure - Repair or replace injection pump.

Engine stalls after starting

Clogged air filter - Service or replace the air filter.
Fuel filter plugged - Service or replace the filter.
Fuel injection pump is leaking - Repair any leaks.
Dirty or defective injectors - Test and replace fuel injectors if necessary.
Defective fuel injection pump - Replace or repair injection pump.

Engine stops running suddenly

Coolant temperature is low - Warm up to required temperature.
Fuel filter element is clogged - Change filter element.
Air in the fuel system - Air bleeding.
Clogged or burnt injection nozzle - Clean or replace injection nozzles.
Timing of fuel injection pump is incorrect - Adjust as recommended.

Engine stalls at idle

Too low idle RPM - Test and adjust.
Fuel injection pump is defective - Replace or repair injection pump.
Defective fuel injectors - Replace or clean fuel injectors.
The valve clearance is not adjusted - Adjust valve clearance.

Diesel engine loses power

Air cleaner is clogged - Install new air cleaner element.
Dirty or faulty injection nozzles - If necessary, replace with a new nozzle.
Incorrect fuel injection pressure - Correct the pressure settings.
The valve clearance is incorrect - Adjust valve clearance.
Low idle speed setting is not correct - Correct low idle adjustment.
Dirty fuel hoses or lines - Clean fuel lines and hoses.
Cylinder head gasket is blown - Change cylinder head gasket.
Damaged or leaking piston rings - Piston rings need to be replaced.

Engine overheating

Low engine coolant - Fill radiator to proper level and check components for faults.
Insufficient engine oil - Add oil to the engine crankcase.
Radiator fins are dirty or radiator cap is defective - Clean radiator or change cap.
Damaged or worn fan belt - Replace the fan belt.
Diesel engine overloaded - Reduce load on the engine.

Insufficient oil pressure

Insufficient engine oil - Fill up the engine oil.
Oil filter element clogged - Replace or service engine oil filter.
Wrong oil viscosity - Drain and refill with oil of correct grade and viscosity.
Incorrect oil clearance in crankshaft bearing - Replace bearings.
Oil pump is worn or damaged - Replace as required.

Engine knocking or noise

Not enough engine oil - Check oil level and add oil as required.
Engine is cold - Normalize the temperature by warming up the engine.
Fuel injection pump timing is not adjusted - Adjust according to specifications.
Incorrect low idle speed adjustment - Correct the settings.
Damaged or clogged injectors - Change or clean fuel injectors.
Connecting rod is defective or not aligned - Align or change connecting rod.
Piston wear or scoring - Have pistons replaced.

Drive System Troubleshooting

Drive system сan't work in either direction

Hydraulic fluid level low - Fill the system to proper hydraulic fluid level.
Track mechanism is defective or jammed - Repair or remedy jamming.
Stuck relief valve - Repair or replace.
Hydraulic filter or suction line is plugged - Change hydraulic filter or service suction line.
Defective foot or hand controls - Repair or replace.
Drive pump or motor is damaged - Replace or repair faulty component.

Machine will not drive straight or drives jerky

Damaged or jammed track mechanism - Remedy jamming or repair tracks.
Tracks are faulty or loose - Adjust track tension or repair tracks.
Foreign objects, debris, or dirt jammed in track frame - Remove debris or foreign objects and clean track frame.

Loss of power

Clogged hydraulic oil filter - Change or service hydraulic filter.
Opened or defective relief valve - Close or change relief valve.
Faulty or damaged transmission components - Inspect and change faulty parts.
Input drive shaft failure - Repair or replace faulty drive shaft.
There is air in the hydraulic system - Bleed air from hydraulic system.

Drive system overheating

Low hydraulic fluid level - Fill the system to proper hydraulic fluid level.
Dirty hydraulic fluid filter - Replace or service hydraulic filter.
Faulty relief valve - Change or repair defective relief valve.
Worn hydraulic motor or drive pump - Repair or change faulty component.
Clogged hydraulic oil cooler - Clean the cooling fins.
Drive system is overloaded - Load should be reduced.

Excessive noise

Oil viscosity is wrong - Use correct oil viscosity.
There is air in the hydraulic system - Bleed air from hydraulic system.
Drive pump or hydraulic motor is damaged - Repair or replace faulty component.
Worn or damaged mechanical parts of drive system - Check the parts for defect or damage and change if required.

Hydraulics Troubleshooting

Hydraulic system has overheating

Incorrect hydraulic pressure setting - Set pressure correctly.
Main relief valve is faulty or misadjusted - Adjust or change relief valve.
Hydraulic oil is contaminated - The oil must be changed.
Hydraulic fluid level is insufficient - Need to add fluid.
Hydraulic pump is worn - Replace or repair pump if necessary.

Lift arm fails to drop or lift

Damaged lift controls - Change or repair.
Hydraulic pump malfunction - Repair or change pump if required.
Faulty hydraulic control valve - Repair or change hydraulic valve.
Hydraulic cylinder not working - Repair or install a new lift cylinder.
Insufficient hydraulic oil - Need to add oil.

Bucket can't tilt

Faulty bucket tilt controls - Replace or repair.
Hydraulic pump not working - Repair or change pump if required.
Hydraulic control valve failure - Repair or change hydraulic valve.
Bucket cylinder failure - Repair or change cylinder.
Insufficient hydraulic oil - Fill the system to proper hydraulic oil level.

Bucket or lift arm moves slowly

Faulty hydraulic oil pump - Check the pump performance and replace it if required.
Leaking hydraulic cylinder - Correct leakage by changing the seals.
Hydraulic oil is insufficient - Check and refill the hydraulic oil.
Worn or unadjusted hydraulic control valve - Repair or set correctly.
Hydraulic pressure has dropped - Adjust pressure as required.

Bucket or boom is jerky

Hydraulic system is leaking air - Air bleeding is required.
Hydraulic oil filter clogging - Service or replace the hydraulic filter.
Hydraulic oil contamination - Fill up with fresh hydraulic oil.
Scored cylinder tube or rod - Replace defective component.

Hydraulic pump makes excessive noise

Hydraulic leaks or low oil level - Correct hydraulic leaks or top up oil as needed.
Hydraulic filter is clogged - Clean or install new filter.
Suction line is dirty - Need to clean the suction line.
Pump is sucking air - Need to bleed air.
Worn pump components - Rebuild or replace hydraulic pump.

Electrical Troubleshooting

Battery will not charge

Loose or corroded electrical wiring connections - Tighten or service cable connections.
Faulty electrical terminal connectors - Install new terminal connectors.
Battery is defective - Use a new battery.
Defective or loose belt - Adjust belt tension or replace belt.

Starter turns slow

Low battery output voltage - Battery is drained, charge it.
Battery drains quickly - Service battery or replace it.
Bad terminals or disconnected battery cables - Check battery wires and service or replace terminals.

Starter will not crank

Battery is discharged or defective - Charge or change the battery.
Battery cables are disconnected or improperly connected - Inspect cables and connect properly.
Low battery output - Recharge the battery.
Starter motor is faulty - Repair or replace starter.