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Bobcat S300 Troubleshooting

The Bobcat S300 skid steer loader driveline system components: a 230 cu.in (3.8L) Kubota V3800-DI-T-E3 4-cycle 4-cylinder direct injection turbocharged diesel engine with a rated power of 77.9 hp (58.1 kW), and fully hydrostatic transmission. The hydraulic system has a pump with a rated capacity of 20.7 gal/min (78.4 l/min). The system relief pressure is 3350 psi (231 bar). The Bobcat S300 is equipped with wet disc brakes and 12x16.5-12 tires. The skid steer loader has a boom lifting force of 5335 lbs (2425 kg) and bucket breakout force of 5390 lbs (2450 kg). The rated operating capacity is 3000 lbs (1362 kg), and tipping load is 6100 lbs (2775 kg).

Engine Troubleshooting

Engine hard to start or doesn't start
Air in fuel system - Bleed fuel system.
Fuel filter plugged - Service the filter.
Fuel injection nozzles are faulty or clogged - Check injection nozzles and replace if required.
Dirt or water in fuel system - Drain water or flush dirt from the system.
Excessive valve clearance - Have it adjusted.
Fuel injection pump malfunctioning - Repair or change injection pump.

Diesel starts and suddenly stops
Plugged air cleaner - Service or replace air cleaner.
Dirty fuel filter - Change filter element.
Fuel injection pump has loose connections - Tighten the connections.
Damaged or clogged injectors - Replace or clean fuel injectors.
Fuel injection pump failure - Replace or rebuild injection pump.

Engine stalls during operation
Coolant temperature is low - Warm up to required temperature.
Dirty fuel filter - Change filter element.
Air in the fuel pipes - Bleed the fuel pipes.
Fuel injection nozzles are damaged - Service or change injection nozzles.
Improper setting of fuel injection pump timing - Adjust the pump as required.

Engine stalls at idle
Low idle speed setting is incorrect - Adjustment required.
Fuel injection pump is not working correctly - Install a new fuel pump or repair.
Defective fuel injectors - Replace fuel injectors.
Improper valve clearance - Check and adjust.

Diesel engine loses power
Dirty air cleaner - Clean or replace air cleaner element.
Fuel injection nozzles are dirty or defective - Change fuel injection nozzles.
Incorrect fuel injection pressure - Test fuel injection pressure and adjust it correctly.
Valve clearance is not correct - Have it adjusted.
Low idle speed setting is incorrect - Adjust low idle speed.
Fuel lines or hoses are clogged - Clean fuel hoses and lines.
Damaged cylinder-head gasket - Cylinder-head gasket replacement required.
Leaking or defective piston rings - Replace piston rings.

Engine is overheated
Low engine coolant - The cooling system needs to be refilled and checked for faults.
Engine oil insufficient - Need to add engine oil.
Clogged radiator core or damaged radiator cap - Install new cap or clean radiator.
Broken or loose fan belt - Replace the fan belt.
Engine is overloaded - Load reducing required.

Oil pressure too low
Insufficient engine oil - Fill the crankcase with oil.
Oil filter element clogging - Change or clean engine oil filter element.
Incorrect engine oil Use oil of proper viscosity.
Crankshaft bearing has excessive oil clearance - Bearing needs to be changed.
Oil pump is defective - Check and replace if necessary.

Abnormal engine noise or knocking
Engine oil level is low - Fill up the oil to required level.
Engine is cold - Normalize the temperature by warming up the engine.
Improper fuel injection timing - Set up as recommended.
Low idle speed setting is not correct - Normalize low idle speed.
Fuel injectors are dirty or defective - Replace or clean fuel injectors.
Connecting rod is not aligned or worn - Connecting rod needs to be replaced or aligned.
Broken or worn pistons - Replace the pistons as required.

Drive System Troubleshooting

Drive system doesn't work in either direction
Low hydraulic fluid level - Fill the system to proper hydraulic fluid level.
Damaged drive chain - Inspect drive chain and replace faulty components.
Damaged input drive shaft - Repair or replace drive shaft.
Relief valve defective or worn - Change or repair defective relief valve.
Clogged hydraulic filter or suction line - Service suction line or replace hydraulic filter.
Worn or damaged foot or hand controls - Replace or repair.
Drive motor or pump is worn - Repair or replace faulty component.

Loss of power
Hydraulic oil filter is plugged - Replace or clean hydraulic filter.
Faulty or opened relief valve - Change or close relief valve.
Faulty or damaged transmission components - Inspect and change defective parts.
Input drive shaft is defective - Repair or replace drive shaft.
Air trapped in hydraulic system - Bleed air from hydraulic system.

Drive system overheating
Hydraulic oil is insufficient - Checking hydraulic oil level and add if necessary.
Hydraulic fluid filter is clogged - Change or service hydraulic filter.
Relief valve is worn or damaged - Repair or install a new relief valve.
Hydraulic motor or drive pump is defective - Check and repair if required.
Oil cooler is clogged - Clean the cooling fins.
Drive system overload - Reduce the load.

Excessive noise
Wrong oil viscosity - Use oil of correct viscosity.
Air leaks in hydraulic system - Bleed air from system.
Worn hydraulic motor or drive pump - Replace or repair faulty component.
Mechanical parts of drive system are damaged or worn - Inspect drive system and replace faulty components.

Hydraulics Troubleshooting

Hydraulic system overheats
Hydraulic pressure incorrectly adjusted - Set pressure correctly.
Main relief valve failure or improper setting - Adjust the valve or replace if necessary.
Hydraulic oil is contaminated - Hydraulic oil change required.
Not enough hydraulic oil in the system - Check oil level and add hydraulic oil as required.
Hydraulic pump is faulty - Repair or replace pump if necessary.

Lift arm cannot be raised or lowered
Lift controls malfunction - Change or repair.
Hydraulic pump malfunction - Change or repair hydraulic pump if required.
Faulty hydraulic control valve - Install a new hydraulic valve or repair it.
Hydraulic cylinder failure - Replace or repair boom cylinder.
Low hydraulic oil level - Need to add oil.

Bucket does not tilt
Bucket tilt controls are damaged - Inspect and repair if necessary.
Defective hydraulic pump - Change or repair hydraulic pump if required.
Hydraulic control valve is defective - Repair or change hydraulic valve.
Hydraulic bucket cylinder not working - Repair or change cylinder.
Insufficient hydraulic fluid - Add fluid as required.

Slow boom or bucket action
Hydraulic pump is faulty - Check pump performance and change it if necessary.
Leaking hydraulic cylinder - Change cylinder piston seals.
Hydraulic oil level low - Fill the system to proper hydraulic oil level.
Hydraulic control valve is unadjusted or worn - Repair or adjust properly.
Hydraulic system loosing pressure - Correct setting is required.

Lift arm or bucket is jerky
Air leaks in hydraulic system - Need to bleed air.
Hydraulic oil filter element is dirty - Clean or replace the filter.
Hydraulic fluid is dirty - The fluid must be changed.
Cylinder tube or rod scoring - Replace damaged component.

Excessive hydraulic pump noise
Hydraulic leakage or low oil level - Top up hydraulic oil or remedy leakage in system.
Clogged hydraulic filter - Clean or install new filter.
Suction line is clogged - Need to service the suction line.
Pump is sucking air - Bleed air.
Damaged pump parts - Replace or rebuild the pump.

Electrical Troubleshooting

Battery is not charging
Wiring connections are loose or corroded - Clean or tighten connections.
Faulty battery terminal clamps - Install new terminal clamps.
Defective battery - Battery change required.
Loose or damaged belt - Adjust belt tension or change the belt.

Starter motor turns slow
Battery power is low - Recharge the battery.
Battery runs out quickly - Service battery or change it.
Disconnected battery cables or bad terminals - Check wiring connections and replace or clean terminals.

Starter does not work
Battery is low or faulty - Recharge or replace battery.
Wiring harness is disconnected or improperly connected - Check wiring harness and connect as required.
Low battery capacity - Battery needs to be recharged.
Damaged starter motor - Starter needs to be changed.