Bobcat S250 Skid Steer Troubleshooting

The Bobcat S250 skid steer loader is powered by 203.2 cu.in (3.3L) Kubota V3300-DI-T 4-cylinder direct injection turbocharged liquid-cooled diesel engine with a rated power of 72.9 hp (54 kW) at 2400 rpm. The Bobcat S250 is equipped with 1-speed or 2-speed transmission, wet disc brakes, and 12x16.5-12 standard tires. The hydraulic system has a pump with fluid flow rate of 20.6 gpm (78.4 lpm). The hydraulic pressure is 3300 psi (227.5 bar). The skid steer loader has a rated operating capacity of 2640 lbs (1200 kg) and tipping load of 5280 lbs (2400 kg). The lift height is 126.4 inches (3210 mm) to hinge pin, and dump height is 99.4 inches (2525 mm).

Engine Troubleshooting

Diesel engine hard to start or doesn't start

Air in fuel tank - Bleed fuel tank.
Fuel filter plugging - Clean the filter element.
Burnt or defective injection nozzle - Check and replace nozzles if required.
Water or dirt in fuel system - Drain, flush, and service the system.
Valve clearance is wrong - Adjust valve clearance.
Fuel injection pump is not operating properly - Rebuild or install a new injection pump.

Engine starts but then stalls

Air filter is clogged - Clean or replace element.
Fuel filter element is clogged - Clean or change the filter.
Fuel injection pump leakage - Check the fuel injection pump for leaks and fix it.
Fuel injectors are dirty or defective - Test and replace fuel injectors if necessary.
Fuel injection pump is defective - Repair or install a new fuel pump.

Engine shuts off suddenly during operation

Engine is not fully warmed up - Warm up the engine as required.
Fuel filter element is dirty - Replace filter element.
Air in the fuel lines - Bleed the fuel lines.
Defective injection nozzle - Change fuel injection nozzles.
Timing of fuel injection pump is incorrect - Adjust fuel injection pump as required.

Engine stops while idling

Too low idle RPM - Correct low idle adjustment.
Fuel injection pump is not operating properly - Replace injection pump or repair it.
Damaged or clogged injectors - Inspect fuel injectors and change as required.
Valve clearance is wrong - Correct valve clearance.

Engine power is insufficient

Dirty air filter - Service or replace the air filter.
Faulty or dirty injection nozzles - Clean or change injection nozzles.
Fuel injection pressure is wrong - Adjust pressure to proper level.
Valve out of adjustment - Adjust valve clearance.
Low idle speed set incorrectly - Adjust low idling as recommended.
Dirt in the fuel lines or hoses - Service fuel hoses and lines.
Defective cylinder head gasket - Gasket should be replaced.
Leaking or damaged piston rings - Replace the piston rings as required.

Engine overheats

Coolant level is low - Add coolant and check the components of cooling system.
Engine oil level is insufficient - Check oil level and add oil as required.
Radiator fins are dirty or radiator cap is defective - Replace cap or clean radiator.
Excessive wear of the fan belt - Replace as required.
Engine is under excessive load - Reduce engine load.

Oil pressure too low

Engine oil level low - Check oil level and add oil as required.
Oil filter is dirty - Service or replace engine oil filter.
Different type of engine oil - Use proper viscosity oil.
Excessive main bearing oil clearance - Bearings need to be reinstalled.
Oil pump failure - Remove and inspect oil pump.

Engine noise or knocking

Engine oil level is insufficient - Fill up the engine oil.
Engine has not warmed up to the recommended temperature - Warm up the engine as required.
Improper setting of fuel injection pump timing - Check the fuel injection pump timing adjustment.
Incorrectly adjusted low idle speed - Adjust low idling as recommended.
Damaged or clogged injectors - Inspect fuel injectors and change as required.
Misaligned or defective connecting rod - Connecting rod needs to be aligned or changed.
Pistons are scored or worn - Pistons replacement required.

Drive System Troubleshooting

Machine will not move in either direction or one direction

Hydraulic oil is insufficient - Check and refill the hydraulic oil.
Faulty drive chain - Check drive chain and change defective components.
Input drive shaft is not working properly - Repair or replace.
Relief valve is worn or damaged - Repair or replace relief valve.
Dirty suction line or hydraulic filter - Clean suction line or replace hydraulic filter.
Worn or defective hand or foot controls - Check and repair as required.
Drive motor or pump is defective - Check and repair if required.

Lack of power

Hydraulic oil filter is dirty - Change hydraulic filter.
Opened or worn relief valve - Replace or close relief valve.
Transmission components are faulty or damaged - Check and change defective components.
Damaged input drive shaft - Change or repair faulty drive shaft.
There is air in the hydraulic system - Bleed hydraulic system.

Drive system is overheated

Hydraulic oil level is low - Check and refill the hydraulic oil.
Hydraulic fluid filter is plugged - Replace hydraulic filter.
Relief valve is not working correctly - Change or repair relief valve.
Hydraulic motor or drive pump is worn - Inspect and change as required.
Hydraulic oil cooler is dirty - Cooling fins need to be cleaned.
Drive system is overloaded - Reduce drive system load.

Drive system makes excessive noise

Oil viscosity is too heavy - Use the specified type of oil.
Air in the hydraulic system - Need to bleed air.
Hydraulic motor or drive pump failure - Check and repair if required.
Mechanical parts of drive system are worn or damaged - Check the parts and change if required.

Hydraulics Troubleshooting

Hydraulic system has overheating

Hydraulic pressure is not adjusted correctly - Hydraulic pressure must be set correctly.
Main relief valve is defective or unadjusted - Adjust or change relief valve.
Hydraulic fluid is contaminated - The fluid must be changed.
Hydraulic oil level is insufficient - Add oil to the hydraulic system.
Hydraulic pump is defective - Replace or repair pump if necessary.

Boom cannot be lowered or raised

Lift controls are faulty - Inspect and repair if necessary.
Hydraulic pump not working - Repair or replace pump if necessary.
Hydraulic control valve failure - Repair or change the valve.
Hydraulic cylinder is broken - Install a new boom cylinder or repair it.
Low hydraulic fluid level - Fill up the hydraulic fluid.

Bucket can't tilt

Defective bucket controls - Replace or repair.
Hydraulic pump failure - Replace or repair pump if necessary.
Hydraulic control valve failure - Change or repair hydraulic valve.
Hydraulic bucket cylinder not working - Replace or repair cylinder.
Low hydraulic oil level - Check and refill the hydraulic oil.

Bucket or lift arm is working slowly

Faulty hydraulic oil pump - Check the pump performance and replace it if required.
Hydraulic cylinder oil leakage - Install new cylinder seals.
Hydraulic oil is insufficient - Checking hydraulic oil level and add if necessary.
Hydraulic control valve is defective or set improper - Adjust correctly or repair.
Hydraulic system loosing pressure - Adjust pressure as required.

Bucket or boom jerks when working

Hydraulic system is leaking air - Bleed air from hydraulic system.
Dirty hydraulic oil filter element - Service or change the hydraulic filter.
Dirty hydraulic fluid - Hydraulic fluid change required.
Scored cylinder tube or rod - Change failed component.

Hydraulic pump is excessively noisy

Lack of oil or hydraulic leakage - Correct hydraulic leaks or top up oil as needed.
Hydraulic filter is clogged - Clean or replace the filter.
Plugged suction line - Clean suction line as required.
Air trapped in hydraulic pump - Bleed air from hydraulics.
Pump components are worn out - Rebuild or change hydraulic pump.

Electrical Troubleshooting

Battery cannot be charged

Loose or corroded wire connections - Clean or tighten wiring connections.
Battery terminal connectors are faulty - Terminal connectors should be replaced.
Battery dead cell - Use a new battery.
Defective or loose belt - Need to adjust belt tension or replace belt.

Starter motor cranks slow

Battery capacity is low - Battery is drained, charge it.
Battery does not hold charge - Service or replace the battery.
Corroded battery terminals or disconnected wires - Connect wires properly or change terminals.

Starter is not cranking

Battery is drained or worn - Need to charge or replace the battery.
Disconnected or incorrectly connected wires - Inspect battery wires and connect correctly.
Battery capacity is low - Charge the battery.
Defective starter motor - Change or repair starter.