Caterpillar 236B3 Skid Steer Troubleshooting

The Caterpillar 236B3 skid steer loader driveline system components: a 207.5 cu.in (3.4L) Cat C3.4 DIT 4-cylinder turbocharged liquid cooled diesel engine with a rated power of 71 hp (53 kW), and 2-speed hydrostatic transmission. The hydraulic system has a pump with a rated capacity of 20.3 gal/min (77 l/min). The system relief pressure is 3335 psi (230 bar). The Cat 236B3 is equipped with radial-lift loader boom, 100HS continuous roller chains, and 12x16.5 tires. The skid steer loader has a max lift height of 122" (3100 mm) to hinge pin and dump height of 94.5" (2400 mm). The rated operating capacity is 1950 lbs (885 kg), and tipping load is 3900 lbs (1770 kg).

Engine Troubleshooting

Engine hard to start or won't start

Air in fuel tank - Bleed fuel tank.
Fuel filter plugged - Change filter element.
Burnt or defective injection nozzle - Clean or replace injection nozzles.
Dirt or water in fuel system - Drain water or flush dirt from the system.
The valve clearance is not adjusted - Adjustment procedure required.
Fuel injection pump malfunctioning - Replace or repair injection pump.

Engine stalls after starting

Air filter is clogged - Install new air filter element.
Fuel filter plugging - Change or clean the filter element.
Fuel injection pump has loose connections - Tighten the connections.
Clogged or defective injectors - Test and replace fuel injectors if necessary.
Defective fuel injection pump - Rebuild or replace pump.

Engine stalls during operation

Engine is not fully warmed up - Warm up to required temperature.
Fuel filter plugging - Clean or replace the filter.
Air trapped in fuel system - Bleed air.
Dirty or faulty injection nozzles - Inspect nozzles and replace if necessary.
Improper setting of fuel injection pump timing - Set up as recommended.

Engine stops at low idle speed

Wrong adjustment of low idle speed - Adjust low idling as recommended.
Fuel injection pump is not operating properly - Rebuild or change fuel pump.
Fuel injector fault - Replace or clean fuel injectors.
Valve clearance is not correct - Adjust valve clearance according to specifications.

Engine power is too low

Air cleaner is dirty - Clean or change cleaner.
Fuel injection nozzles are dirty or defective - Inspect nozzles and replace if necessary.
Improper fuel injection pressure - Adjust to correct pressure.
Valve clearance is not correct - Check and adjust.
Incorrectly adjusted low idle speed - Adjust low idle speed.
Fuel lines or hoses are dirty - Clean fuel system hoses and lines.
Leaking cylinder head gasket - Install new cylinder head gasket.
Piston rings are worn or damaged - Replace the piston rings as required.

Engine overheats

Lack of engine coolant - Add coolant fluid and inspect the cooling system for leaks.
Not enough engine oil - Checking oil level and add if necessary.
Dirty radiator fins or defective radiator cap - Clean radiator or change cap.
Damaged or worn fan belt - Change as required.
Diesel engine overloaded - Load reducing required.

Oil pressure is low

Oil level is low - Need to add oil.
Oil filter clogging - Clean or change engine oil filter.
Oil grade or viscosity is wrong - Drain and refill with oil of correct grade and viscosity.
Incorrect oil clearance in main bearing - Bearing replacement required.
Oil pump malfunction - Repair or change.

Engine noise or knocking

Engine oil level is low - Checking oil level and add if necessary.
Low coolant temperature - Warm up the engine.
Fuel injection pump timing is not adjusted - Set it up as required.
Incorrectly adjusted low idle speed - Adjust low idle speed.
Defective fuel injectors - Clean or replace fuel injectors.
Connecting rod is not aligned or defective - Need to align or replace the connecting rod.
Worn or broken pistons - Have pistons replaced.

Drive System Troubleshooting

Machine will not move in either direction or one direction

Low hydraulic fluid level - Check and refill the hydraulic fluid.
Drive chain is damaged - Inspect drive chain and replace faulty parts.
Worn input drive shaft - Replace drive shaft.
Defective or worn relief valve - Relief valve need to be replaced or repair.
Hydraulic filter or suction line is dirty - Service suction line or replace hydraulic filter.
Worn or defective hand or foot controls - Repair or replace.
Drive motor or pump is defective - Inspect and replace as necessary.

Loss of power

Hydraulic oil filter is clogged - Check, clean, or replace as required.
Open or faulty relief valve - Close or replace relief valve.
Transmission parts are damaged or faulty - Check and replace defective components.
Defective input drive shaft - Replace drive shaft.
Air in hydraulic system - Air bleeding is required.

Drive system is overheated

Insufficient hydraulic fluid - Checking hydraulic fluid level and add if necessary.
Hydraulic fluid filter is plugged - Change or clean hydraulic filter.
Relief valve is not working correctly - Relief valve need to be replaced or repair.
Hydraulic motor or drive pump is worn - Repair or change faulty component.
Clogged hydraulic oil cooler - Clean cooling fins as required.
Overloaded drive system - Reduce drive system load.

Excessive noise

Oil viscosity is too heavy - Use proper oil viscosity.
Air trapped in hydraulic system - Need to bleed air.
Drive pump or hydraulic motor is damaged - Change or repair faulty component.
Mechanical parts of drive system are defective or worn - Inspect drive system and replace faulty parts.

Hydraulics Troubleshooting

Hydraulic system has overheating

Incorrect hydraulic pressure setting - Adjust pressure correctly.
Main relief valve is defective or unadjusted - Set up or change the relief valve.
Hydraulic oil is contaminated - Hydraulic oil change required.
Hydraulic oil level is insufficient - Fill up the hydraulic oil.
Hydraulic pump is faulty - Install new pump or repair it.

Boom won't lower or raise

Defective lift controls - Check and repair as required.
Defective hydraulic pump - Install new pump or repair it.
Hydraulic control valve is faulty - Repair or change the valve.
Hydraulic cylinder is defective - Replace or repair boom cylinder.
Hydraulic oil is insufficient - Need to add oil.

Bucket does not tilt

Faulty bucket tilt controls - Check and repair as required.
Damaged hydraulic oil pump - Install new pump or repair it.
Damaged hydraulic control valve - Repair or change the valve.
Damaged bucket cylinder - Repair or replace cylinder.
Hydraulic fluid level low - Checking hydraulic fluid level and add if necessary.

Bucket or lift arm runs slowly

Faulty hydraulic oil pump - Flow-rate hydraulic pump and replace pump if necessary.
Oil leaks from hydraulic cylinder - Cylinder seals need to be replaced.
Low hydraulic fluid level - Fill the system to proper hydraulic fluid level.
Faulty or incorrect setting hydraulic control valve - Adjust correctly or repair.
Hydraulic pressure has dropped - Correct setting is required.

Bucket or boom movements are jerky

Air trapped in hydraulic system - Bleed hydraulic system.
Hydraulic oil filter element is dirty - Replace or clean the filter.
Hydraulic oil is dirty - Change hydraulic oil.
Scratched cylinder rod or tube - Change damaged component.

Hydraulic pump is noisy

Lack of oil or hydraulic leakage - Add hydraulic oil or correct system leaks.
Hydraulic filter clogging - Clean or replace the filter.
Suction line clogging - Service the suction line.
Air enters the pump - Need to bleed air.
Damaged pump parts - Change or rebuild pump.

Electrical Troubleshooting

Battery cannot be charged

Corroded or loose cable connections - Service or tighten cable connections.
Faulty battery terminal clamps - Terminal clamps should be changed.
Dead cell in battery - Install a new battery.
Belt is loose or defective - Need to adjust belt tension or replace belt.

Starter turns slowly

Low battery output voltage - Battery is drained, recharge it.
Battery is not holding charge - Battery needs to be serviced or replaced.
Terminals are faulty or battery cables are disconnected - Connect wiring correctly or install new terminals.

Starter doesn't crank

Battery is discharged or defective - Battery needs to be recharged or replaced.
Wiring is incorrectly connected or disconnected - Inspect wiring and connect correctly.
Low battery capacity - Charge the battery.
Faulty starter motor - Replace or repair starter.