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Home / Wheel Loaders / Case Wheel Loaders / Case 521D

Case 521D Troubleshooting

The Case 521D wheel loader driveline system components: 238 cu.in (3.9L) Case 4TA-390 4-cylinder turbocharged liquid-cooled diesel engine with a rated power of 110 hp (82 kW), and 4x3 powershift transmission with single stage torque converter. The hydraulic system has a piston pump with a rated capacity of 35.4 gal/min (134 l/min). The Case 521D is equipped with a power steering system, hydraulic wet disc brakes, and 17.5x25 tires. The wheel loader has a maximum lift height to hinge pin of 142.1" (3610 mm) and boom breakout force of 18200 lbs (8255 kg). The rated operating capacity is 7115 lbs (3227 kg), and tipping load is 14230 lbs (6455 kg).

Engine Troubleshooting

Engine hard to start or will not start
Air in fuel system - Bleed fuel system.
Fuel filter plugging - Clean or replace the filter.
Fuel injection nozzles are damaged - Test injection nozzles and change if necessary.
Water in the fuel system - Change fuel and repair fuel system.
Valve clearance is not correct - Adjust to proper valve clearance.
Defective fuel injection pump - Replacement or repair required.

Diesel starts and suddenly stops
Air filter is plugged - Clean or change filter.
Fuel filter plugged - Clean or replace the filter.
Problems with fuel injection pump tightness - Inspect fuel injection pump for leaks.
Damaged or clogged injectors - Clean or replace fuel injectors.
Fuel injection pump failure - Rebuild or install a new injection pump.

Diesel shuts off while driving
Coolant temperature is low - Warm up engine as required.
Fuel filter element is clogged - Change filter element.
Air in fuel system - Bleed fuel system.
Faulty fuel injection nozzles - Install a new kit of correctly balanced nozzles.
Timing of fuel injection pump is incorrect - Adjust according to specifications.

Engine stalls when idling
Incorrectly adjusted low idle speed - Need to adjust idle speed.
Fuel injection pump is faulty - Repair or install a new fuel pump.
Clogged or defective injectors - Clean fuel injectors or change it.
Valve out of adjustment - Need to adjust valve clearance.

Engine power is too low
Air cleaner is dirty - Install new air cleaner element.
Faulty or dirty injection nozzles - Service or change injection nozzles.
Fuel injection pressure is incorrect - Check the fuel injection pressure and adjust if necessary.
Incorrect valve clearance - Adjust to proper valve clearance.
Incorrectly adjusted low idle speed - Adjust as required.
Dirt in the fuel lines or hoses - Service fuel hoses and lines.
Defective cylinder head gasket - Install new cylinder head gasket.
Piston rings are broken or leaking - Piston rings replacement required.

Engine overheats
Coolant level is low - Add coolant fluid to cooling system and also check it for leaks.
Engine oil level low - Checking oil level and add if necessary.
Faulty radiator cap or dirty radiator fins - Clean radiator or replace cap.
Broken or loose fan belt - Belt change is required.
Diesel engine overloaded - Reduce engine load.

Oil pressure is low
Low crankcase oil level - Add oil as required.
Clogged oil filter element - Change or service engine oil filter.
Different type of engine oil - Fill up with the proper oil viscosity.
Excessive main bearing oil clearance - Bearings need to be reinstalled.
Oil pump is damaged - Remove and inspect oil pump.

Engine knocks or noises
Insufficient engine oil - Fill up the engine oil.
Coolant temperature is low - Warm up engine as required.
Timing of fuel injection pump is incorrect - Adjust fuel injection pump as required.
Incorrect low idle setting - Adjust low idle speed.
Clogged or defective injectors - Clean fuel injectors or change it.
Connecting rod failure or misalignment - Connecting rod needs to be aligned or changed.
Piston wear or scoring - Replace the pistons.

Transmission Troubleshooting

Transmission oil pressure is low
Lack of transmission oil supply - Fill up the transmission oil.
Transmission oil filter is dirty (if equipped) - Service or change transmission oil filter.
Relief valve is damaged - Replace the valve.

Transmission noises
Low fluid level - Check and refill the transmission fluid.
Transmission oil contamination - Transmission oil change required.
Incorrect backlash or gears are worn - Install new gears and adjust backlash properly.
Worn or broken bearings - Replace the bearings.
Damaged or worn gear shift forks - Replace the shift forks.
Worn or stuck shaft splines - Change the shaft.

Gears are hard to shift
Corroded or worn gear shift linkage - Lubricate or replace the shift linkage.
Damaged or worn gear shift forks - Replace the shift forks.
Gearshift mechanism is damaged - Replace or repair the mechanism.
Clutch is worn or not adjusted - Clutch needs to be replaced or adjusted.

Transmission fluid leakage
Transmission fluid level is exceeded - Excess fluid must be drained.
Seals or gaskets are worn - Gaskets or seal need to be replaced.

Hydraulics Troubleshooting

Hydraulic system is overheated
Hydraulic pressure incorrectly adjusted - Adjust pressure correctly.
Main relief valve malfunction or improper adjustment - Adjust or change relief valve.
Contaminated hydraulic fluid - The fluid must be changed.
Hydraulic fluid level is insufficient - Need to add fluid.
Defective hydraulic pump - Replace or repair pump if necessary.

Lift arm cannot be raised or lowered
Lift controls are defective - Replace or repair.
Damaged hydraulic oil pump - Change or repair hydraulic pump if required.
Faulty hydraulic control valve - Install a new valve or repair it.
Defective hydraulic cylinder - Change or repair lift cylinder.
Insufficient hydraulic oil - Checking hydraulic oil level and add if necessary.

Bucket tilt does not work
Damaged bucket controls - Repair or change.
Hydraulic pump failure - Repair or change pump if required.
Hydraulic control valve failure - Replace or repair the valve.
Hydraulic bucket cylinder not working - Repair or change cylinder.
Hydraulic oil level low - Check and refill the hydraulic oil.

Bucket or lift arm is moving slowly
Hydraulic pump is worn - Test pump flow rate and replace pump if required.
Leaking hydraulic cylinder - Repair leak by replacing the seals.
Low hydraulic fluid level - Fill up the hydraulic fluid.
Defective or not adjusted hydraulic control valve - Adjust properly or repair.
Hydraulic pressure loss - Correct adjustment is required.

Bucket or boom is working jerkily
Air leaks in hydraulic system - Air bleeding is required.
Hydraulic oil filter element is clogged - Clean or replace the filter.
Dirty hydraulic oil - The oil must be changed.
Scratched cylinder rod or tube - Replace damaged component.

Excessive hydraulic pump noise
Not enough oil or hydraulic system leaking - Remedy hydraulic leakage or refill oil as necessary.
Hydraulic filter is clogged - Replace or clean the filter.
Clogged suction line - Service the suction line.
Air trapped in hydraulic pump - Remove air from hydraulics.
Worn pump parts - Replace or rebuild the pump.

Electrical Troubleshooting

Battery cannot be charged
Loose or corroded electrical wiring connections - Service or tighten cable connections.
Defective battery terminal connectors - Terminal connectors need to be changed.
Dead cell in battery - Use a new battery.
Belt is damaged or loose - Change belt or adjust belt tension.

Starter turns slowly
Low battery capacity - Low battery charging, charge as required.
Battery runs out quickly - Service or replace the battery.
Faulty battery terminals or disconnected cables - Check cables and clean or change terminals.

Starter is not working
Battery is drained or defective - Charge or change the battery.
Battery cables are disconnected or incorrectly connected - Check cables and connect as needed.
Battery power is low - Battery is drained, recharge it.
Faulty starter motor - Repair or replace starter.

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WHEEL LOADERS SPECIFICATIONS

Wheel Loaders, Skid Steers, and Compact Track Loaders