Bobcat S150 Skid Steer Troubleshooting

The Bobcat S150 skid steer loader driveline system components: a 134.1 cu.in (2.2L) Kubota V2203 M-DI-E2B 4-cylinder direct injection naturally aspirated diesel engine with a rated power of 46 hp (34.3 kW), and hydrostatic transmission. The hydraulic system has a pump with a rated capacity of 16.6 gal/min (63 l/min). The system relief pressure is 3300 psi (228 bar). The Bobcat S150 is equipped with wet disc brakes and 10x16.5-10 tires. The skid steer loader has a boom lifting force of 4350 lbs (1975 kg) and bucket breakout force of 3600 lbs (1635 kg). The rated operating capacity is 700 lbs (318 kg), and tipping load is 1400 lbs (636 kg).

Engine Troubleshooting

Engine starts up hard or doesn't start

Air in the fuel system - Air bleeding.
Fuel filter element is dirty - Clean or replace the filter.
Dirty or damaged injection nozzles - Clean or change injection nozzles.
Water in the fuel system - Change fuel and repair fuel system.
Valve clearance is wrong - Check and adjust as required.
Fuel injection pump is faulty - Repair or replace injection pump.

Engine starts and immediately shuts off

Air cleaner is dirty - Clean or replace air cleaner element.
Fuel filter element clogging - Clean the filter or install new filter element.
Poor fuel injection pump tightness - Look for any leaks of fuel pump, tighten it fast.
Fuel injectors are faulty or clogged - Replace fuel injectors.
Fuel injection pump is not operating properly - Change or repair the pump.

Engine stalls while running

Engine is not warmed up to the required temperature - Warm up engine as required.
Fuel filter element is clogged - Clean or replace the filter.
Air in the fuel system - Air bleeding.
Fuel injection nozzles fault - Check and replace nozzles if required.
Improper fuel injection timing - Adjust the pump as required.

Engine stops when idling

Incorrect low idle speed adjustment - Need to adjust idle speed.
Damaged fuel injection pump - Repair or install a new fuel pump.
Fuel injectors are faulty or clogged - Clean or replace fuel injectors.
Improper valve clearance - Adjustment procedure required.

Lack of engine power

Air cleaner is clogged - Clean or change cleaner.
Defective injection nozzle - Service or change injection nozzles.
Insufficient fuel injection pressure - Adjust to proper pressure.
Valve out of adjustment - Check and adjust as required.
Low idle speed adjustment is incorrect - Adjustment required.
Restricted fuel hoses or lines - Clean fuel system hoses and lines.
Cylinder-head gasket is leaking - Change cylinder head gasket.
Piston rings are damaged or leaking - Install new piston rings.

Engine overheated

Lack of engine coolant - Fill radiator to proper level and check components for faults.
Lack of engine oil - Fill the crankcase with engine oil.
Clogged radiator fins or damaged radiator cap - Clean radiator or install new cap.
Fan belt is worn or faulty - Fan belt must be replaced.
Diesel engine overloaded - Reduce load on the engine.

Oil pressure is insufficient

Oil level is low - Fill the crankcase with oil.
Clogged oil filter element - Replace or service engine oil filter.
Improper type of engine oil - Drain crankcase and refill with correct oil.
Crankshaft bearing oil clearance is excessive - Change bearings.
Worn oil pump - Repair or replace.

Engine noises or knocks

Engine oil insufficient - Checking oil level and add if necessary.
Low coolant temperature - Normalize the temperature by warming up the engine.
Fuel injection pump timing is wrong - Adjust fuel injection pump as required.
Low idle speed adjustment is incorrect - Test and adjust.
Defective fuel injectors - Test and replace fuel injectors if necessary.
Connecting rod misalignment or failure - Alignment procedure or replacement is required.
Worn or broken pistons - Have pistons replaced.

Drive System Troubleshooting

Drive system will not operate in either direction

Hydraulic fluid is insufficient - Checking hydraulic fluid level and add if necessary.
Drive chain malfunction - Inspect drive chain and replace faulty parts.
Input drive shaft malfunctioning - Replace or service the drive shaft.
Stuck relief valve - Repair or install a new relief valve.
Suction line or hydraulic filter is dirty - Clean suction line or change hydraulic filter.
Hand or foot controls malfunction - Change or repair.
Drive pump or motor is damaged - Replace or repair faulty component.

Power is too low

Dirty hydraulic oil filter - Check, clean, or replace as required.
Opened or defective relief valve - Close or change relief valve.
Transmission components are damaged or faulty - Check and replace defective components.
Input drive shaft malfunction - Faulty drive shaft need to be replaced or repair.
Hydraulic system is leaking air - Bleed air from hydraulic system.

Drive system keeps overheating

Hydraulic fluid level low - Check and refill the hydraulic fluid.
Clogged hydraulic fluid filter - Change or clean hydraulic filter.
Defective relief valve - Repair or install a new relief valve.
Hydraulic motor or drive pump failure - Inspect and replace as necessary.
Dirty oil cooler - Cooling fins should be cleaned.
Drive system overloaded continuously - Load needs to be reduced.

Drive system is noisy

Oil viscosity is incorrect - Use proper oil viscosity.
There is air in the hydraulic system - Air bleeding is required.
Hydraulic motor or drive pump is defective - Change or repair faulty component.
Defective or worn mechanical parts of drive system - Check drive system and change faulty components.

Hydraulics Troubleshooting

Hydraulic system overheated

Hydraulic pressure is not correct - Adjust it correctly.
Defective or misadjusted main relief valve - Adjust or replace the relief valve.
Hydraulic oil contamination - Fill up with fresh hydraulic oil.
Hydraulic fluid level is insufficient - Check and refill the hydraulic fluid.
Hydraulic pump is worn - Repair or change pump if required.

Lift arm does not lower or raise

Defective lift controls - Replace or repair.
Defective hydraulic pump - Repair or change pump if required.
Damaged hydraulic control valve - Repair or change hydraulic valve.
Damaged hydraulic cylinder - Repair or replace hydraulic cylinder.
Insufficient hydraulic oil - Check and refill the hydraulic oil.

Bucket won't move

Bucket tilt controls malfunction - Change or repair.
Damaged hydraulic oil pump - Repair or change pump if required.
Defective hydraulic control valve - Repair or replace hydraulic valve.
Faulty hydraulic bucket cylinder - Install a new cylinder or repair it.
Low hydraulic fluid level - Fill the system to proper hydraulic fluid level.

Bucket or lift arm functions slowly

Hydraulic pump is defective - Test pump flow rate and replace pump if required.
Hydraulic cylinder leaking - Correct leakage by changing the seals.
Hydraulic fluid level low - Fill the system to proper hydraulic fluid level.
Faulty or incorrect setting hydraulic control valve - Repair or adjust correctly.
Hydraulic pressure has dropped - Set pressure correctly.

Bucket or boom is working jerkily

There is air in the hydraulic system - Bleed air from system.
Hydraulic oil filter is clogged - Change or clean oil filter.
Hydraulic oil is dirty - Hydraulic oil change required.
Cylinder tube or rod is scored - Change damaged component.

Hydraulic pump is noisy

Insufficient oil level or leaking hydraulic system - Remedy hydraulic leakage or refill oil as necessary.
Hydraulic filter is dirty - Clean or change the filter.
Suction line is dirty - Service the suction line.
Pump is sucking air - Bleed air.
Pump components are damaged - Rebuild or replace hydraulic pump.

Electrical Troubleshooting

Battery will not charge

Loose or corroded electrical wiring connections - Tighten or clean connections.
Defective battery terminal clamps - Install new terminal clamps.
Faulty cell in battery - Change the battery.
Belt is worn or loose - Belt needs to be adjusted or changed.

Starter turns slowly

Low battery capacity - Low battery charging, charge as required.
Battery won’t hold charge - Battery needs service or replacement.
Disconnected wires or corroded battery terminals - Connect wires correctly or change terminals.

Starter is not working

Battery is drained or defective - Charge or replace the battery.
Wiring harness is disconnected or improperly connected - Check wiring harness and connect as required.
Low battery output - Battery is drained, recharge it.
Starter motor is defective - Starter needs to be replaced.