Caterpillar 279C Track Loader Troubleshooting

The Caterpillar 279C compact track loader driveline system components: a 201.2 cu.in (3.3L) Cat C3.4 DIT 4-cylinder direct injection turbocharged diesel engine with a rated power of 84 hp (63 kW), and 2-speed hydrostatic transmission. The hydraulic system has a pump with a rated flow of 22 gpm (84 lpm). The system pressure is 3335 psi (230 bar). The Caterpillar 279C is equipped with planetary final drives, steel embedded rubber tracks, and wet multi disc brakes. The loader has a lift height of 123.2" (3130 mm) to hinge pin and bucket breakout force of 7310 lbs (3315 kg). The rated operating capacity is 2240 lbs (1016 kg), and tipping load is 6480 lbs (2940 kg).

Engine Troubleshooting

Engine difficult to start or will not start

Air in the fuel lines - Bleed the fuel lines.
Fuel filter plugged - Replace filter element.
Dirty or faulty injection nozzles - Test injection nozzles and change if necessary.
Water or dirt in fuel system - Drain, flush, and service the system.
Improper valve clearance - Correct valve clearance needs to be set.
Fuel injection pump is not working correctly - Replacement or repair required.

Diesel starts and stops

Plugged air filter - Change or service air filter element.
Fuel filter element is dirty - Change or clean the filter element.
Poor fuel injection pump tightness - Look for any leaks of fuel pump, tighten it fast.
Damaged or clogged injectors - Inspect fuel injectors and change as required.
Fuel injection pump is not operating properly - Replace or repair injection pump.

Diesel shuts off while driving

Engine has not warmed up to the recommended temperature - Warm up to required temperature.
Dirty fuel filter - Replace the filter element.
Air in the fuel system - Air bleeding.
Fuel injection nozzles are dirty or defective - Service or change injection nozzles.
Wrong setting of fuel injection pump timing - Set the fuel pump timing correctly.

Engine stops while idling

Wrong adjustment of low idle speed - Correct the settings.
Defective fuel injection pump - Repair or change injection pump.
Fuel injector fault - Change or clean fuel injectors.
Valve clearance is not correct - Correct valve clearance.

Engine power is too low

Air cleaner is clogged - Clean or change.
Dirty or damaged injection nozzles - Install a new kit of correctly balanced nozzles.
Improper fuel injection pressure - Correct the pressure settings.
Incorrect valve clearance - Adjust to proper valve clearance.
Incorrect low idle setting - Adjust the low idle speed.
Fuel lines or hoses clogging - Service fuel lines and hoses.
Blown cylinder head gasket - Gasket should be replaced.
Piston rings are defective or leaking - Install new piston rings.

Engine is overheated

Insufficient coolant fluid - Fill radiator to proper level and check components for faults.
Low engine oil level - Check and refill engine oil.
Clogged radiator core or leaking radiator cap - Replace cap or clean radiator.
Broken or loose fan belt - Replace as required.
Engine overload - Reduce load on the engine.

Oil pressure is insufficient

Engine oil insufficient - Need to add oil.
Dirty oil filter - Change or clean engine oil filter element.
Oil grade or viscosity is incorrect - Use oil of correct viscosity.
Incorrect oil clearance in crankshaft bearing - Bearings need to be reinstalled.
Worn oil pump - Replace as required.

Engine noise or knocking

Not enough engine oil - Checking oil level and add if necessary.
Engine not warmed up - Warm up to required temperature.
Incorrect adjustment of fuel injection pump timing - Set up as recommended.
Low idle speed setting is not correct - Adjust low idling as recommended.
Clogged or defective injectors - Replace fuel injectors.
Connecting rod misalignment or failure - Replace or align connecting rod.
Pistons are worn or broken - Replace the pistons.

Drive System Troubleshooting

Drive system сan't work in either direction

Low hydraulic oil level - Fill the system to proper hydraulic oil level.
Track mechanism is damaged or blocked - Correct blockage or repair tracks.
Relief valve malfunction - Service or change relief valve.
Hydraulic filter or suction line is plugged - Clean suction line or replace hydraulic filter.
Defective hand or foot controls - Repair or change.
Defective drive pump or motor - Repair or replace faulty component.

Machine is not moving straight or moving is jerky

Jammed or damaged track mechanism - Remove jamming or repair tracks.
Loose or worn tracks - Adjust track tension as required or replace tracks.
Track frame is blocked with debris, dirt, or foreign objects - Remove foreign objects or clean track frame.

Power is too low

Hydraulic oil filter is dirty - Replace or service hydraulic filter.
Worn or open relief valve - Replace or close relief valve.
Transmission components are faulty or damaged - Check and replace defective components.
Input drive shaft is worn - Repair or install a new drive shaft.
Air leaks in hydraulic system - Bleed hydraulic system.

Drive system overheating

Low hydraulic fluid level - Checking hydraulic fluid level and add if necessary.
Clogged hydraulic fluid filter - Replace or service hydraulic filter.
Worn or defective relief valve - Repair or replace.
Damaged drive pump or hydraulic motor - Repair or replace faulty component.
Clogged hydraulic oil cooler - Cooling fins should be cleaned.
Drive system overload - Reduce loading.

Drive system is noisy

Oil viscosity is wrong - Use oil of correct viscosity.
Air in hydraulic system - Bleed air from system.
Drive pump or hydraulic motor malfunction - Inspect and replace as necessary.
Worn or defective mechanical components of drive system - Check the parts and replace if required.

Hydraulics Troubleshooting

Hydraulic system overheating

Hydraulic pressure is incorrect - Adjust pressure correctly.
Defective or misadjusted main relief valve - Adjust relief valve or change if required.
Hydraulic oil contamination - Change hydraulic oil.
Hydraulic oil level is low - Check oil level and add hydraulic oil as required.
Defective hydraulic pump - Repair or install new hydraulic pump.

Lift arm fails to drop or lift

Lift controls failure - Repair or change.
Hydraulic pump not working - Replace or repair pump if necessary.
Hydraulic control valve malfunction - Repair or replace hydraulic valve.
Faulty hydraulic cylinder - Install a new boom cylinder or repair it.
Insufficient hydraulic oil - Need to add oil.

Bucket does not function

Faulty bucket tilt controls - Change or repair.
Defective hydraulic pump - Repair or change pump if required.
Hydraulic control valve is faulty - Replace or repair the valve.
Broken bucket cylinder - Change or repair cylinder.
Low hydraulic oil level - Checking hydraulic oil level and add if necessary.

Bucket or lift arm functions slowly

Worn hydraulic oil pump - Check the pump capacity and replace pump if required.
Leaking hydraulic cylinder - Cylinder seals need to be replaced.
Hydraulic oil is insufficient - Need to add oil.
Defective or not adjusted hydraulic control valve - Repair or set correctly.
Low hydraulic pressure - Correct setting is required.

Bucket or boom is moving jerkily

Air in hydraulic system - Need to bleed air.
Hydraulic oil filter is clogged - Change or clean oil filter.
Hydraulic fluid is dirty - Change hydraulic fluid.
Scratched cylinder rod or tube - Replace damaged component.

Excessive hydraulic pump noise

Not enough oil or hydraulic system leaking - Top up hydraulic oil or remedy leakage in system.
Plugged hydraulic filter - Clean or change the filter.
Plugged suction line - Clean suction line as required.
Air trapped in hydraulic pump - Need to bleed air.
Worn pump components - Rebuild or install new pump.

Electrical Troubleshooting

Battery is not charging

Electrical wire connections are corroded or loose - Tighten or clean electrical wiring connections.
Battery terminal clamps are defective - Terminal clamps need to be replaced.
Battery is defective - Replace the battery.
Belt is worn or loose - Adjust belt tension or change the belt.

Starter turns slow

Low battery output voltage - Low battery charging, charge as required.
Battery is draining quickly - Battery needs service or replacement.
Battery terminals are corroded or wires are disconnected - Check battery wires and service or replace terminals.

Starter will not work

Battery is discharged or defective - Replace or charge as required.
Wiring is incorrectly connected or disconnected - Inspect wiring and connect correctly.
Low battery output - Low battery charging, charge as required.
Defective starter motor - Starter needs to be replaced.