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Doosan DL250-7 Troubleshooting

The Doosan DL250-7 wheel loader driveline system components: 359 cu.in (5.9L) Doosan DL06 vertical 6-cylinder turbocharged diesel engine with a rated power of 172 hp (128 kW), and 4-speed or 5-speed powershift transmission with a torque converter. The hydraulic system has a pump with a rated capacity of 40.9 gal/min (155 l/min). The Doosan DL250-7 is equipped with a power steering, hydraulic dual multi-disc brakes, and 20.5R25 tires. The wheel loader has a max lift height to hinge pin of 151.8" (3855 mm) and breakout force of 26025 lbs (11830 kg). The rated operating capacity is 10670 (4850 kg), and tipping load is 21340 lbs (9700 kg).

Engine Troubleshooting

Engine difficult to start or doesn't start
Air trapped in fuel system - Bleed air.
Clogged fuel filter - Filter maintenance required.
Burnt or clogged injection nozzle - Test injection nozzles and change if necessary.
Water in the fuel system - Change fuel and repair fuel system.
Valve clearance is not correct - Adjust valve clearance.
Faulty fuel injection pump - Change or repair the pump.

Engine starts and immediately shuts off
Plugged air filter - Clean or change filter.
Fuel filter element clogging - Change or clean the filter element.
Fuel injection pump leakage - Check the fuel injection pump for leaks and fix it.
Defective or clogged fuel injectors - Test and replace fuel injectors if necessary.
Fuel injection pump is defective - Repair or install a new fuel pump.

Diesel shuts off while driving
Low coolant temperature - Warm up to required temperature.
Fuel filter element is dirty - Change filter element.
There is air in the fuel system - Bleed the system.
Fuel injection nozzles are faulty or clogged - Clean or change injection nozzles.
Timing of fuel injection pump is incorrect - Adjust fuel injection pump as required.

Engine stops while idle
Low idle speed set incorrectly - Test and adjust.
Fuel injection pump is not operating properly - Repair or replace injection pump.
Defective fuel injectors - Change or clean fuel injectors.
Valve clearance is wrong - Adjust to proper valve clearance.

Diesel engine loses power
Clogged air cleaner - Install new air cleaner element.
Clogged injection nozzle - Inspect nozzles and replace if necessary.
Incorrect fuel injection pressure - Adjust to correct pressure.
Improper valve clearance - Have it adjusted.
Low idle speed set incorrectly - Adjust the low idle speed.
Fuel hoses or lines are dirty - Fuel hoses and lines must be clean.
Cylinder head gasket is damaged - Replace cylinder head gasket.
Defective or worn piston rings - Piston rings need to be replaced.

Engine overheats
Coolant level is low - Refill to the correct level and inspect system for leaks.
Low engine oil level - Fill up the engine oil.
Clogged radiator core or leaking radiator cap - Replace cap or clean radiator.
Loose or defective fan belt - Replace the fan belt.
Engine is overloaded - Reduce load on the engine.

Insufficient oil pressure
Oil level is low - Checking oil level and add if necessary.
Oil filter element is dirty - Clean or change engine oil filter.
Incorrect engine oil Drain and refill with oil of correct grade and viscosity.
Crankshaft bearing oil clearance is excessive - Bearing needs to be changed.
Oil pump is worn or damaged - Install a new pump.

Engine noise or knocking
Engine oil level is insufficient - Add oil to the engine crankcase.
Engine is not warmed up to required temperature - Normalize the temperature by warming up the engine.
Improper fuel injection timing - Adjust according to specifications.
Low idle speed set incorrectly - Normalize low idle speed.
Fuel injector fault - Replace or clean fuel injectors.
Connecting rod is not aligned or worn - Alignment procedure or replacement is required.
Worn or scored pistons - Pistons replacement required.

Transmission Troubleshooting

Transmission oil pressure is low
Insufficient transmission fluid - Add fluid to the transmission housing.
Transmission oil filter is clogged (if fitted) - Clean or change transmission oil filter.
Defective relief valve - Replace relief valve.

Transmission makes excessive noise
Insufficient transmission oil - Fill the transmission housing to proper oil level.
Transmission fluid contamination - Change the fluid.
Incorrect backlash or gears are worn - Adjust backlash properly or replace the gears.
Worn or broken bearings - Change the bearings.
Shift forks are worn or bent - Replace the shift forks.
Shaft splines are damaged or worn - Shaft need to be changed.

Hard shifting
Stuck or worn gear shift linkage - Install a new gear shift linkage.
Shift forks are worn or bent - Shift forks need to be replaced.
Gearshift mechanism malfunction - Identify and replace failed parts.
Worn or improperly adjusted clutch - Clutch needs to be adjusted or changed.

Transmission fluid leakage
Too much fluid in transmission - Excess fluid must be drained.
Seals or gaskets are worn - Change defective gaskets or seal.

Hydraulics Troubleshooting

Hydraulic system is overheated
Incorrect hydraulic pressure setting - Correct adjustment is required.
Main relief valve is damaged or adjusted improperly - Set up or change the relief valve.
Hydraulic oil contamination - Change hydraulic oil.
Lack of hydraulic fluid - Check and refill the hydraulic fluid.
Hydraulic pump is worn - Replace or repair pump if necessary.

Lift arm fails to drop or lift
Damaged lift controls - Repair or change.
Defective hydraulic pump - Repair or change pump if required.
Hydraulic control valve malfunction - Repair or change hydraulic valve.
Broken hydraulic cylinder - Repair or replace hydraulic cylinder.
Low hydraulic oil level - Fill the system to proper hydraulic oil level.

Bucket tilt does not work
Bucket controls failure - Change or repair.
Hydraulic pump is broken - Change or repair hydraulic pump if required.
Hydraulic control valve malfunction - Install a new valve or repair it.
Hydraulic bucket cylinder is defective - Install a new cylinder or repair it.
Insufficient hydraulic fluid - Fill up the hydraulic fluid.

Bucket or lift arm functions slowly
Worn hydraulic oil pump - Test pump flow rate and replace pump if required.
Hydraulic cylinder leaking - Repair leak by replacing the seals.
Hydraulic fluid is insufficient - Checking hydraulic fluid level and add if necessary.
Damaged or incorrect adjusted hydraulic control valve - Set properly or repair.
Hydraulic pressure loss - Adjust pressure correctly.

Bucket or boom is moving jerkily
There is air in the hydraulic system - Bleed air from system.
Hydraulic oil filter is dirty - Replace or clean the filter.
Hydraulic fluid is contaminated - Fill up with fresh hydraulic fluid.
Scratched cylinder rod or tube - Replace damaged component.

Hydraulic pump is noisy
Hydraulic leakage or low oil level - Repair hydraulic leaks or add oil as required.
Clogged hydraulic filter - Service or replace hydraulic filter.
Suction line is dirty - Need to clean the suction line.
Pump sucks air - Need to bleed air.
Pump components are faulty - Rebuild or change hydraulic pump.

Electrical Troubleshooting

Battery won’t charge
Corroded or loose electrical wire connections - Service or tighten connections.
Faulty battery terminal clamps - Install new terminal clamps.
Defective battery - Battery replacement required.
Belt is defective or loose - Adjust belt tension or change the belt.

Starter turns slow
Battery voltage is low - Recharge the battery.
Battery is draining quickly - Battery needs service or replacement.
Bad terminals or disconnected battery cables - Connect wiring properly or install new terminals.

Starter doesn't crank
Battery is discharged or worn - Battery needs to be recharged or replaced.
Battery wires are disconnected or incorrectly connected - Check wires and connect correctly.
Low battery output voltage - Charge the battery.
Faulty starter motor - Replace or repair starter.

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WHEEL LOADERS SPECIFICATIONS

Caterpillar