Bobcat S550 Skid Steer Troubleshooting

The Bobcat S550 skid steer loader driveline system components: a 158.7 cu.in (2.6L) Kubota V2607 four-cylinder turbocharged diesel engine with a rated power of 61 hp (45.5 kW), and 1-speed or 2-speed transmission. The hydraulic system has a pump with a rated capacity of 17.1 gal/min (64.7 l/min). The system relief pressure is 3550 psi (245 bar). The Bobcat S550 is equipped with a radial-lift loader boom, 80 HSOC roller chains, and 10x16.5 or 31-12x16.5 tires. The skid steer has a boom lifting force of 4237 lbs (1926 kg) and bucket breakout force of 4070 lbs (1850 kg). The rated operating capacity is 1750 lbs (794 kg), and tipping load is 3500 lbs (1588 kg).

Engine Troubleshooting

Engine starts hard or will not start

Air in fuel tank - Bleed fuel tank.
Dirty fuel filter - Change filter element.
Fuel injection nozzles are faulty or clogged - Check and replace nozzles if required.
Water or dirt in fuel system - Drain, flush, and service the system.
Valve clearance is out of adjustment - Adjust to proper valve clearance.
Fuel injection pump failure - Install a new pump or rebuild.

Engine stalls after starting

Plugged air cleaner - Clean or change cleaner.
Fuel filter plugging - Change filter element.
Fuel injection pump is leaking - Repair any leaks.
Defective or clogged fuel injectors - Change or clean fuel injectors.
Fuel injection pump malfunctioning - Install a new fuel pump or repair.

Engine shuts off while running

Low coolant temperature - Warm up the engine.
Dirty fuel filter - Change the filter element.
Air in the fuel pipes - Bleed the fuel pipes.
Dirty or faulty injection nozzles - Check and replace nozzles if required.
Fuel injection pump timing is not adjusted - Set up as recommended.

Engine stops while idle

Improperly adjusted low idle speed - Correct low idle settings.
Fuel injection pump is defective - Rebuild or change fuel pump.
Defective fuel injectors - Replace or clean fuel injectors.
The valve clearance is incorrect - Have it adjusted.

Engine power is too low

Plugged air filter - Clean or replace element.
Damaged or dirty injection nozzles - Service or change injection nozzles.
Fuel injection pressure is incorrect - Adjust to correct pressure.
Incorrect valve clearance - Adjust valve clearance according to specifications.
Low idle speed setting is incorrect - Adjust low idle speed.
Dirty fuel lines or hoses - Clean fuel system lines and hoses.
Cylinder head gasket defective - Replace the gasket as required.
Leaking or damaged piston rings - Install new piston rings.

Engine is overheated

Coolant level is low - Fill radiator to proper level and check components for faults.
Insufficient engine oil - Fill up the oil to required level.
Damaged radiator cap or dirty radiator core - Replace cap or clean radiator.
Loose or damaged fan belt - Replace the fan belt.
Diesel engine is overloaded - Load reducing is recommended.

Low oil pressure

Engine oil insufficient - Need to add oil.
Engine oil filter is plugged - Clean or replace engine oil filter element.
Wrong oil viscosity - Fill up with the proper oil viscosity.
Excessive oil clearance of crankshaft bearing - Install new bearings.
Oil pump is worn or damaged - Remove and inspect oil pump.

Engine noises or knocks

Lack of engine oil - Checking oil level and add if necessary.
Engine is not preheated - Warm up engine as required.
Fuel injection pump timing is not adjusted - Use the correct fuel injection pump timing adjustment.
Low idle speed setting is incorrect - Adjust the low idle speed.
Dirty or defective injectors - Test and replace fuel injectors if necessary.
Connecting rod is defective or misaligned - Need to align or replace the connecting rod.
Pistons are worn or scored - Install new pistons.

Drive System Troubleshooting

Drive system won't work in one direction or either direction

Insufficient hydraulic fluid - Fill the system to proper hydraulic fluid level.
Drive chain failure - Inspect drive chain and replace defective parts.
Worn input drive shaft - Repair or replace drive shaft.
Stuck relief valve - Service or change relief valve.
Suction line or hydraulic filter is dirty - Replace hydraulic filter or clean suction line.
Foot or hand controls are defective - Repair or change.
Drive pump or motor malfunction - Inspect and replace as necessary.

Low power

Clogged hydraulic oil filter - Change or service hydraulic filter.
Defective or open relief valve - Replace or close relief valve.
Transmission parts are worn or defective - Inspect and change faulty parts.
Defective input drive shaft - Repair or install a new drive shaft.
Hydraulic system is leaking air - Need to bleed air.

Drive system keeps overheating

Hydraulic oil is insufficient - Fill the system to proper hydraulic oil level.
Plugged hydraulic fluid filter - Check, clean, or replace as required.
Relief valve failure - Change or repair relief valve.
Hydraulic motor or drive pump is worn - Inspect and replace as necessary.
Plugged hydraulic oil cooler - Clean the cooling fins.
Drive system is overloaded - Reduce the load.

Drive system makes excessive noise

Wrong oil viscosity - Use oil of proper viscosity.
Air leaks in hydraulic system - Air bleeding is required.
Hydraulic motor or drive pump is worn - Repair or replace faulty component.
Mechanical parts of drive system are damaged or worn - Check the components for defect or damage and change if necessary.

Hydraulics Troubleshooting

Hydraulic system is overheated

Incorrect hydraulic pressure setting - Correct setting is required.
Main relief valve is defective or unadjusted - Adjust or replace the relief valve.
Hydraulic oil contamination - Change hydraulic oil.
Lack of hydraulic oil - Check oil level and add hydraulic oil as required.
Faulty hydraulic oil pump - Repair or change pump if required.

Lift arm cannot be raised or lowered

Lift controls malfunction - Replace or repair.
Hydraulic pump failure - Change or repair hydraulic pump if required.
Defective hydraulic control valve - Repair or replace the valve.
Hydraulic cylinder malfunction - Repair or replace hydraulic cylinder.
Insufficient hydraulic oil - Fill the system to proper hydraulic oil level.

Bucket fails to tilt

Defective bucket controls - Check and repair as required.
Hydraulic pump failure - Install new pump or repair it.
Faulty hydraulic control valve - Change or repair hydraulic valve.
Hydraulic bucket cylinder is defective - Change or repair cylinder.
Insufficient hydraulic fluid - Checking hydraulic fluid level and add if necessary.

Bucket or lift arm is working slowly

Defective hydraulic pump - Check the pump capacity and replace pump if required.
Oil leaks from hydraulic cylinder - Install new cylinder seals.
Hydraulic fluid level low - Add fluid as required.
Faulty or incorrect setting hydraulic control valve - Repair or adjust correctly.
Hydraulic system loosing pressure - Adjust pressure as required.

Jerky operation of the bucket or boom

There is air in the hydraulic system - Air bleeding is required.
Hydraulic oil filter element clogging - Clean or install new filter.
Hydraulic oil is dirty - Fill up with fresh hydraulic oil.
Scratched cylinder rod or tube - Replace failed component.

Hydraulic pump is noisy

Leaking hydraulic system or insufficient oil level - Remedy hydraulic leakage or refill oil as necessary.
Clogged hydraulic filter - Clean or replace the filter.
Plugged suction line - Suction line must be serviced.
Air in hydraulic pump - Bleed air.
Damaged pump components - Rebuild or change hydraulic pump.

Electrical Troubleshooting

Battery will not charge

Loose or corroded wire connections - Tighten or service cable connections.
Electrical terminal connectors are defective - Terminal connectors need to be changed.
Battery dead cell - Battery change required.
Belt is worn or loose - Belt needs to be adjusted or replaced.

Starter turns slow

Low battery output voltage - Battery needs to be recharged.
Battery is draining quickly - Service or change the battery.
Bad terminals or disconnected battery cables - Check cable connections and replace or service terminals.

Starter motor won't turn

Battery is discharged or defective - Replace or charge as required.
Battery cables are disconnected or incorrectly connected - Check cables and connect as needed.
Low battery capacity - Recharge the battery.
Starter motor is defective - Starter should be changed.