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Caterpillar 256C Troubleshooting

The Caterpillar 256C skid steer loader driveline system components: a 207.5 cu.in (3.4L) Caterpillar C3.4 DIT four-cycle four-cylinder turbocharged diesel engine with a rated power of 82 hp (61 kW), and 1-speed or 2-speed hydrostatic transmission. The hydraulic system has a pump with a rated capacity of 22 gal/min (84 l/min) or 33 gal/min (125 l/min). The Cat 256C is equipped with a radial-lift loader boom, 100HS drive chains, and 12.00x16.5 standard tires. The skid steer loader has a max lift height of 122.9" (3120 mm) to hinge pin and dump height of 95.4" (2425 mm). The rated operating capacity is 2350 lbs (1065 kg), and tipping load is 4700 lbs (2130 kg).

Engine Troubleshooting

Engine difficult to start or will not start
Air in fuel system - Bleed fuel system.
Dirty fuel filter - Clean the filter element.
Burnt or clogged injection nozzle - Install a new kit of correctly balanced nozzles.
Dirt or water in fuel system - Drain water or flush dirt from the system.
The valve clearance is not adjusted - Need to adjust valve clearance.
Defective fuel injection pump - Change or repair the pump.

Engine starts but stalls suddenly
Clogged air filter - Service or replace the air filter.
Clogged fuel filter - Change filter element.
Fuel injection pump is leaking - Repair any leaks.
Damaged or clogged injectors - Clean or replace fuel injectors.
Fuel injection pump malfunction - Repair or install new pump.

Engine stalls during operation
Engine is not fully warmed up - Warm up to required temperature.
Fuel filter element is clogged - Service or replace the filter.
Air in the fuel pipes - Bleed the fuel pipes.
Defective or clogged injection nozzle - Install a new kit of correctly balanced nozzles.
Improper setting of fuel injection pump timing - Check the fuel injection pump timing adjustment.

Engine shuts off while idling
Wrong adjustment of low idle speed - Adjustment required.
Fuel injection pump is not operating properly - Replacement or repair required.
Clogged or defective injectors - Change or clean fuel injectors.
Valve clearance is not correct - Correct valve clearance needs to be set.

Loss of engine power
Plugged air filter - Install new air filter element.
Defective injection nozzle - Inspect nozzles and replace if necessary.
Fuel injection pressure is wrong - Test fuel injection pressure and adjust it correctly.
Improper valve clearance - Have it adjusted.
Low idle speed set incorrectly - Adjust low idle speed.
Clogged fuel hoses or lines - Service fuel hoses and lines.
Cylinder-head gasket is leaking - Gasket should be replaced.
Piston rings are broken or leaking - Piston rings replacement required.

Engine is overheated
Insufficient coolant - Fill the cooling system and check components for leaks or other faults.
Insufficient engine oil - Fill the crankcase with engine oil.
Clogged radiator core or damaged radiator cap - Clean radiator or replace cap.
Loose or defective fan belt - Change as required.
Engine overloaded - Load reducing is recommended.

Oil pressure is insufficient
Engine oil insufficient - Need to add oil.
Clogged oil filter - Replace or service engine oil filter.
Wrong oil viscosity - Use oil of correct viscosity.
Crankshaft bearing oil clearance is excessive - Bearing replacement required.
Oil pump is damaged - Repair or change.

Engine knocking or noise
Not enough engine oil - Fill up the engine oil.
Engine has not warmed up to the recommended temperature - Warm up to required temperature.
Fuel injection pump timing is wrong - Set it up as required.
Too low idle RPM - Correct low idle settings.
Defective fuel injectors - Clean or replace fuel injectors.
Connecting rod is defective or misaligned - Connecting rod must be aligned or replaced.
Worn or broken pistons - Pistons need to be replaced.

Drive System Troubleshooting

Drive system won't work in one direction or either direction
Low hydraulic oil level - Check and refill the hydraulic oil.
Drive chain fault - Check drive chain and change defective components.
Relief valve worn or defective - Repair or replace relief valve.
Suction line or hydraulic filter is plugged - Replace hydraulic filter or clean suction line.
Defective or worn foot or hand controls - Replace or repair.
Damaged drive pump or motor - Repair or change faulty component.

Low power
Hydraulic oil filter is dirty - Change or service hydraulic filter.
Open or faulty relief valve - Replace or close relief valve.
Worn or defective transmission parts - Inspect and change faulty parts.
Input drive shaft is damaged - Replace drive shaft.
Air trapped in hydraulic system - Bleed air from hydraulic system.

Overheated drive system
Hydraulic fluid is insufficient - Add fluid as required.
Hydraulic fluid filter is clogged - Change hydraulic filter.
Defective relief valve - Repair or install a new relief valve.
Defective drive pump or hydraulic motor - Inspect and change as required.
Hydraulic oil cooler is plugged - Clean the cooling fins.
Transmission overloading - Load should be reduced.

Drive system is excessively noisy
Oil viscosity is incorrect - Use the specified type of oil.
Hydraulic system is leaking air - Bleed air from hydraulic system.
Defective drive pump or hydraulic motor - Replace or repair faulty component.
Mechanical components of drive system are worn or damaged - Inspect drive system and replace faulty components.

Hydraulics Troubleshooting

Hydraulic system overheating
Incorrect hydraulic pressure setting - Hydraulic pressure must be set correctly.
Unadjusted or defective main relief valve - Adjust relief valve or change if required.
Hydraulic oil is dirty - The oil must be changed.
Hydraulic fluid level is insufficient - Fill the hydraulic system with oil.
Hydraulic pump is faulty - Repair or replace pump if necessary.

Lift arm cannot be raised or lowered
Lift controls failure - Repair or replace.
Hydraulic pump malfunction - Repair or replace pump if necessary.
Hydraulic control valve is faulty - Repair or replace the valve.
Broken hydraulic cylinder - Change or repair lift cylinder.
Insufficient hydraulic oil - Check and refill the hydraulic oil.

Bucket can't tilt
Faulty bucket tilt controls - Check and repair as required.
Hydraulic pump malfunction - Repair or install new hydraulic pump.
Damaged hydraulic control valve - Change or repair hydraulic valve.
Defective bucket cylinder - Repair or install a new cylinder.
Hydraulic fluid is insufficient - Add fluid as required.

Bucket or lift arm moves slowly
Worn hydraulic oil pump - Check pump flow and install new pump if necessary.
Oil leaks from hydraulic cylinder - Change cylinder piston seals.
Insufficient hydraulic oil - Check and refill the hydraulic oil.
Hydraulic control valve is faulty or out of adjustment - Set properly or repair.
Low hydraulic pressure - Set pressure correctly.

Lift arm or bucket is jerky
Air leaks in hydraulic system - Need to bleed air.
Dirty hydraulic oil filter - Change or clean oil filter.
Hydraulic fluid contamination - Change hydraulic fluid.
Scored cylinder tube or rod - Replace damaged component.

Hydraulic pump is excessively noisy
Hydraulic leakage or lack of oil - Top up hydraulic oil or remedy leakage in system.
Hydraulic filter clogging - Clean or change the filter.
Dirty suction line - Suction line must be serviced.
Air in hydraulic pump - Remove air from hydraulics.
Pump components are faulty - Rebuild or install new pump.

Electrical Troubleshooting

Battery cannot be charged
Corroded or loose cable connections - Tighten or clean electrical wiring connections.
Electrical terminal connectors are defective - Terminal connectors should be replaced.
Battery dead cell - Replace the battery.
Belt is damaged or loose - Replace belt or adjust belt tension.

Starter motor cranks slow
Low battery voltage - Low battery charging, charge as required.
Battery will not hold charge - Service charging system or change battery.
Terminals are faulty or battery cables are disconnected - Connect wires properly or change terminals.

Starter motor is not working
Battery is discharged or defective - Recharge or change battery.
Disconnected or improperly connected wiring harness - Inspect battery wiring harness and connect as required.
Low battery power - Battery is drained, charge it.
Starter motor is defective - Repair or install a new starter.

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SKID STEER LOADERS SPECIFICATIONS