____________________________________________________________________________________

Home / Skid Steer Loaders / Bobcat Skid Steer Loaders / Bobcat 553

Bobcat 553 Troubleshooting

The Bobcat 553 skid steer loader is powered by 68.5 cu.in (1.1L) Kubota D1105-B three-cylinder iIndirect injection water-cooled diesel engine with a rated power of 24.8 hp (18.5 kW) at 2200 rpm. The Bobcat 553 is equipped with a radial-lift loader boom, one-speed hydrostatic transmission, 60HS drive chains, and 27x8.50x15 standard tires. The hydraulic system has a pump with fluid flow rate of 11 gpm (41.6 lpm). The hydraulic pressure is 2900 psi (200 bar). The skid steer loader has a rated operating capacity of 950 lbs (431 kg) and tipping load of 1905 lbs (864 kg). The lift height is 103.7 inches (2635 mm) to hinge pin, and dump height is 82 inches (2085 mm).

Engine Troubleshooting

Engine starts hard or doesn't start
Air in fuel tank - Bleed fuel tank.
Dirty fuel filter - Service the filter.
Fuel injection nozzles are dirty or defective - Change fuel injection nozzles.
Water or dirt in fuel system - Drain, flush, and service the system.
Valve out of adjustment - Check and adjust as required.
Fuel injection pump is damaged - Repair or install a new fuel pump.

Diesel starts and stops
Air filter is clogged - Clean or replace element.
Clogged fuel filter - Change the filter element.
Problems with fuel injection pump tightness - Inspect fuel injection pump for leaks.
Dirty or defective injectors - Inspect fuel injectors and change as required.
Fuel injection pump is defective - Replace or repair injection pump.

Engine shuts off while running
Engine is not fully warmed up - Warm up to required temperature.
Clogged fuel filter - Change filter element.
Air in the fuel system - Air bleeding.
Fuel injection nozzles are dirty or defective - Install a new kit of correctly balanced nozzles.
Incorrect adjustment of fuel injection pump timing - Adjust according to specifications.

Engine stops at low idle speed
Incorrect low idle setting - Adjustment required.
Fuel injection pump is faulty - Repair or install a new fuel pump.
Defective fuel injectors - Replace or clean fuel injectors.
Improper valve clearance - Adjustment procedure required.

Engine power is insufficient
Plugged air cleaner - Clean or change.
Faulty fuel injection nozzles - Change fuel injection nozzles.
Incorrect fuel injection pressure - Adjust pressure to proper level.
Valve out of adjustment - Adjust to proper valve clearance.
Low idle speed adjustment is incorrect - Adjust the low idle speed.
Dirty fuel hoses or lines - Clean fuel system hoses and lines.
Defective cylinder head gasket - Install new cylinder head gasket.
Piston rings are damaged or leaking - Replace piston rings.

Engine overheated
Lack of engine coolant - Fill the cooling system and check components for leaks or other faults.
Lack of engine oil - Add oil to the engine crankcase.
Clogged radiator fins or leaking radiator cap - Clean radiator or install new cap.
Loose or damaged fan belt - Belt replacement is recommended.
Engine is overloaded - Reduce load on the engine.

Oil pressure is low
Lack of oil - Check and refill the oil.
Oil filter is dirty - Change or service engine oil filter.
Improper type of engine oil - Use proper viscosity oil.
Crankshaft bearing oil clearance is excessive - Bearing needs to be changed.
Oil pump is damaged - Remove and inspect oil pump.

Engine knocking sound or abnormal noise
Engine oil level low - Add oil to the engine crankcase.
Engine is not fully warmed up - Warm up the engine.
Incorrect adjustment of fuel injection pump timing - Set up as recommended.
Low idle speed setting is incorrect - Adjustment required.
Dirty or defective injectors - Clean or replace fuel injectors.
Connecting rod is not aligned or defective - Connecting rod must be aligned or replaced.
Pistons are worn or broken - Pistons need to be replaced.

Drive System Troubleshooting

Machine is not moving forward or backward
Insufficient hydraulic oil - Checking hydraulic oil level and add if necessary.
Drive chain malfunction - Check drive chain and change defective components.
Worn or defective relief valve - Relief valve need to be replaced or repair.
Plugged suction line or hydraulic filter - Check, clean, or change if necessary.
Hand or foot controls malfunction - Check and repair as required.
Worn drive motor or pump - Replace or repair faulty component.

Lack of power
Clogged hydraulic oil filter - Change or service hydraulic filter.
Faulty or opened relief valve - Replace or close relief valve.
Worn or defective transmission parts - Check and replace defective components.
Defective input drive shaft - Repair or replace drive shaft.
Air in hydraulic system - Air bleeding is required.

Drive system overheats
Insufficient hydraulic oil - Check and refill the hydraulic oil.
Plugged hydraulic fluid filter - Replace or clean hydraulic filter.
Faulty relief valve - Repair or replace.
Hydraulic motor or drive pump is worn - Repair or replace faulty component.
Plugged hydraulic oil cooler - Cooling fins should be cleaned.
Transmission overloading - Reduce drive system load.

Drive system is excessively noisy
Improper oil viscosity - Use oil of correct viscosity.
Air trapped in hydraulic system - Bleed hydraulic system.
Hydraulic motor or drive pump is worn - Change or repair faulty component.
Mechanical parts of drive system are worn or damaged - Check the components for worn or defect and replace if necessary.

Hydraulics Troubleshooting

Hydraulic system overheating
Hydraulic pressure is not adjusted correctly - Correct adjustment is required.
Main relief valve is damaged or adjusted improperly - Adjust or replace the relief valve.
Hydraulic oil is contaminated - The oil must be changed.
Not enough hydraulic oil in the system - Fill the hydraulic system with oil.
Worn hydraulic oil pump - Repair or install new hydraulic pump.

Lift arm can't drop or lift
Lift controls malfunction - Change or repair.
Hydraulic pump malfunction - Repair or install new hydraulic pump.
Hydraulic control valve failure - Install a new valve or repair it.
Hydraulic cylinder is faulty - Repair or install a new lift cylinder.
Insufficient hydraulic oil - Need to add oil.

Bucket is not working
Bucket controls failure - Inspect and repair if necessary.
Hydraulic pump is broken - Repair or install new hydraulic pump.
Hydraulic control valve malfunction - Install a new valve or repair it.
Hydraulic bucket cylinder is defective - Repair or change cylinder.
Hydraulic oil level low - Fill the system to proper hydraulic oil level.

Bucket or lift arm runs slowly
Worn hydraulic oil pump - Check the pump capacity and replace pump if required.
Hydraulic cylinder leaking - Cylinder seals need to be replaced.
Hydraulic oil is insufficient - Check and refill the hydraulic oil.
Faulty or incorrect setting hydraulic control valve - Repair or adjust properly.
Hydraulic pressure is low - Set pressure correctly.

Lift arm or bucket is jerky
Air in hydraulic system - Air bleeding is required.
Hydraulic oil filter element is dirty - Service or replace the hydraulic filter.
Hydraulic fluid is contaminated - Change hydraulic fluid.
Cylinder tube or rod is scored - Change failed component.

Excessive hydraulic pump noise
Lack of oil or hydraulic leakage - Refill hydraulic oil or repair leaks in system.
Dirty hydraulic filter - Change or clean oil filter.
Dirty suction line - Service the suction line.
Pump sucks air - Bleed air.
Pump parts are faulty - Rebuild or change hydraulic pump.

Electrical Troubleshooting

Battery will not charge
Loose or corroded electrical wiring connections - Tighten or service cable connections.
Battery terminal clamps are faulty - Install new terminal clamps.
Battery is worn - Install a new battery.
Loose or worn belt - Need to adjust belt tension or replace belt.

Starter turning slow
Low battery capacity - Battery is drained, recharge it.
Battery drains quickly - Battery needs to be serviced or replaced.
Bad battery terminals or disconnected wiring - Check cables and service or change terminals.

Starter motor won't turn
Battery is drained or defective - Recharge or change battery.
Wiring is improperly connected or disconnected - Check wiring and connect properly.
Low battery voltage - Recharge the battery.
Faulty starter motor - Replace or repair starter.

____________________________________________________________________________________

____________________________________________________________________________________

SKID STEER LOADERS SPECIFICATIONS