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Bobcat AL350 Troubleshooting

The Bobcat AL350 articulated wheel loader driveline system components: a 203.2 cu.in (3.3L) Kubota V3300-DI 4-cylinder liquid-cooled diesel engine with a rated power of 60.5 hp (45.1 kW), and two-range hydrostatic transmission. The hydraulic system has a gear pump with a rated capacity of 16.9 gal/min (64 l/min). The system relief pressure is 3625 psi (250 bar). The Bobcat AL350 is equipped with a power steering system, hydraulic drum brakes, and 375/75R20 tires. The wheel loader has a max lift height of 126" (3200 mm) and breakout force of 10760 lbs (4890 kg). The rated operating capacity is 3465 lbs (1575 kg), and tipping load is 6930 lbs (3150 kg).

Engine Troubleshooting

Engine hard to start or won't start
Air in the fuel system - Air bleeding.
Fuel filter element is clogged - Service or replace the filter.
Fuel injection nozzles are dirty or defective - Install a new kit of correctly balanced nozzles.
Water or dirt in fuel system - Drain, flush, and service the system.
Improper valve clearance - Adjust valve clearance.
Fuel injection pump malfunction - Rebuild or change fuel pump.

Diesel starts and stalls immediately
Plugged air cleaner - Clean or change cleaner.
Clogged fuel filter - Change filter element.
Fuel injection pump is leaking - Repair any leaks.
Defective or clogged fuel injectors - Replace or clean fuel injectors.
Faulty fuel injection pump - Repair or install new pump.

Engine shuts off while running
Coolant temperature is low - Warm up engine as required.
Fuel filter is plugged - Clean or change the filter.
Air in the fuel pipes - Bleed the fuel pipes.
Damaged or dirty injection nozzles - Clean or change injection nozzles.
Incorrect adjustment of fuel injection pump timing - Use the correct fuel injection pump timing adjustment.

Engine stalls at idle
Incorrectly set low idle speed - Adjust low idle speed.
Fuel injection pump malfunctioning - Change pump or rebuild it.
Clogged or defective injectors - Replace or clean fuel injectors.
The valve clearance is incorrect - Adjust valve clearance.

Diesel power loss
Air filter is clogged - Clean or replace element.
Fuel injection nozzles are faulty or clogged - If necessary, replace with a new nozzle.
Insufficient fuel injection pressure - Test fuel injection pressure and adjust it correctly.
Valve clearance is wrong - Correct valve clearance.
Incorrectly adjusted low idle speed - Adjust the low idle speed.
Fuel hoses or lines are dirty - Fuel hoses and lines must be clean.
Cylinder head gasket is blown - Replace cylinder head gasket.
Piston rings are leaking or defective - Change piston rings.

Engine is overheated
Low engine coolant - The cooling system needs to be refilled and checked for faults.
Engine oil level is low - Check and refill engine oil.
Radiator fins are clogged or radiator cap is faulty - Change cap or clean radiator.
Broken or loose fan belt - Replace as required.
Diesel engine is overloaded - Reduce load on the engine.

Oil pressure too low
Engine oil insufficient - Checking oil level and add if necessary.
Clogged oil filter element - Service or replace engine oil filter.
Wrong oil viscosity - Fill up with the proper oil viscosity.
Main bearing oil clearance is excessive - Install new bearings.
Oil pump failure - Check and replace if necessary.

Engine knocks or noises
Engine oil insufficient - Checking oil level and add if necessary.
Engine not warmed up - Warm up the engine.
Improper setting of fuel injection pump timing - Adjust as recommended.
Low idle speed adjustment is incorrect - Adjust low idling as recommended.
Dirty or defective injectors - Clean or replace fuel injectors.
Connecting rod is misaligned or worn - Need to change or align the connecting rod.
Pistons are scored or worn - Install new pistons.

Hydrostatic Transmission Troubleshooting

Hydrostatic transmission noises
Transmission fluid is dirty or fluid level is too low - Fill to required level or change the fluid.
Worn or out of adjustment speed control linkage - Adjust or replace linkage.
Relief valve is stuck - Install a new relief valve.
Transmission overload - Load needs to be reduced.
Worn or defective transmission components - Replace or repair defective components.

Lack of power
Low oil level - Fill the transmission housing to proper oil level.
Defective relief valve - Change the valve.
Defective or not adjusted speed control pedal linkage - Adjust or change linkage.

Transmission oil overheating
Low oil level - Check transmission oil level and add oil as required.
Transmission fluid filter element is clogged - Replace or service transmission fluid filter.
Clogged or damaged cooling components - Inspect all cooling components and replace or clean if necessary.
Excessive loading - Reduce loading.

External oil leaks
Damaged seals or gaskets - Gaskets or seal need to be replaced.
High internal transmission case pressure - Repair or replace damaged components.
Plugged oil return tube - Clean or replace return tube.

Hydraulics Troubleshooting

Hydraulic system is overheated
Hydraulic pressure is not adjusted correctly - Adjust it correctly.
Main relief valve is damaged or adjusted improperly - Adjust the valve or replace if necessary.
Hydraulic fluid contamination - Fill up with fresh hydraulic fluid.
Hydraulic oil level is low - Check oil level and add hydraulic oil as required.
Hydraulic pump is defective - Install new pump or repair it.

Boom does not raise or lower
Damaged lift controls - Replace or repair.
Hydraulic pump not working - Repair or install new hydraulic pump.
Hydraulic control valve malfunction - Replace or repair the valve.
Hydraulic cylinder malfunction - Repair or install a new lift cylinder.
Hydraulic oil level low - Checking hydraulic oil level and add if necessary.

Bucket can't tilt
Bucket tilt controls are defective - Check and repair as required.
Hydraulic pump is broken - Install new pump or repair it.
Hydraulic control valve failure - Change or repair hydraulic valve.
Broken bucket cylinder - Install a new cylinder or repair it.
Hydraulic oil is insufficient - Checking hydraulic oil level and add if necessary.

Boom or bucket functions slowly
Hydraulic pump is worn - Check pump capacity and change if necessary.
Oil leaks from hydraulic cylinder - Change cylinder piston seals.
Low hydraulic fluid level - Add fluid as required.
Hydraulic control valve is faulty or out of adjustment - Adjust properly or repair.
Low hydraulic pressure - Adjust it correctly.

Lift arm or bucket jerks when working
Air in the hydraulic system - Bleed hydraulic system.
Dirty hydraulic oil filter element - Service or change the hydraulic filter.
Contaminated hydraulic oil - Change hydraulic oil.
Cylinder tube or rod scoring - Replace failed component.

Hydraulic pump is excessively noisy
Hydraulic system leaking or not enough oil - Top up hydraulic oil or remedy leakage in system.
Hydraulic filter clogging - Clean or replace the filter.
Dirty suction line - Suction line needs to be cleaned.
Air trapped in hydraulic pump - Need to bleed air.
Faulty pump parts - Replace or rebuild the pump.

Electrical Troubleshooting

Battery will not charge
Electrical wire connections are corroded or loose - Clean or tighten connections.
Electrical terminal connectors are faulty - Install new terminal connectors.
Battery failing - Use a new battery.
Belt is damaged or loose - Belt needs to be adjusted or changed.

Starter motor turns slow
Battery power is low - Battery is drained, recharge it.
Battery drains quickly - Battery needs service or replacement.
Corroded battery terminals or disconnected wires - Check wiring and clean or replace terminals.

Starter is not working
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 output - Recharge the battery.
Faulty starter motor - Starter should be replaced.