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Case 420 Troubleshooting

The Case 420 Series 3 skid steer loader driveline system components: a 195 cu.in (3.2L) Case 432T/M3 4-cylinder direct injection turbocharged diesel engine with a rated power of 74 hp (55 kW), and 2-speed hydrostatic transmission. The hydraulic system has a pump with a rated capacity of 23.8 gal/min (90 l/min). The system relief pressure is 3050 psi (210 bar). The Case 420 is equipped with a radial-lift boom, 100HV continuous roller chains, and 12x16.5 standard tires. The skid steer has a max lift height of 120.7" (3060 mm) to hinge pin and dump height of 96.1" (2440 mm). The rated operating capacity is 1850 lbs (840 kg), and tipping load is 3700 lbs (1680 kg).

Engine Troubleshooting

Engine difficult to start or won't start
There is air in the fuel system - Bleed the system.
Fuel filter element clogging - Change the filter element.
Damaged or dirty injection nozzles - Check injection nozzles and replace if required.
Water or dirt in fuel system - Drain, flush, and service the system.
Incorrect valve clearance - Adjust valve clearance.
Fuel injection pump is faulty - Rebuild or install a new injection pump.

Engine starts but stalls immediately
Clogged air cleaner - Clean or change cleaner.
Clogged fuel filter - Change filter element.
Fuel injection pump leakage - Check the fuel injection pump for leaks and fix it.
Defective or clogged fuel injectors - Replace fuel injectors.
Fuel injection pump is not working correctly - Repair or install a new fuel pump.

Engine shuts off while running
Engine is not preheated - Warm up engine as required.
Dirty fuel filter - Service or replace the filter.
Air in the fuel system - Air bleeding.
Defective injection nozzle - Check injection nozzles and replace if required.
Incorrect adjustment of fuel injection pump timing - Check the fuel injection pump timing adjustment.

Engine stops when idling
Incorrectly set low idle speed - Adjust the low idle speed.
Fuel injection pump is defective - Repair or change injection pump.
Defective fuel injectors - Replace or clean fuel injectors.
Improper valve clearance - Adjustment procedure required.

Loss of engine power
Clogged air cleaner - Clean or change cleaner.
Defective or clogged injection nozzle - Inspect nozzles and replace if necessary.
Uneven fuel injection pressure - Adjust to proper pressure.
Improper valve clearance - Correct valve clearance needs to be set.
Incorrectly set low idle speed - Adjust low idle speed.
Dirty fuel hoses or lines - Clean fuel system lines and hoses.
Cylinder head gasket is worn - Cylinder-head gasket replacement required.
Piston rings are damaged or leaking - Replace the piston rings as required.

Engine overheating
Engine has a lack of coolant - The cooling system needs to be refilled and checked for faults.
Low engine oil level - Check and refill engine oil.
Clogged radiator fins or damaged radiator cap - Replace cap or clean radiator.
Fan belt is broken or worn - Belt change is required.
Engine is overloaded - Load reducing required.

Low oil pressure
Oil level is insufficient - Check oil level and add oil as required.
Oil filter clogging - Change or service engine oil filter.
Improper type of engine oil - Use the specified type of engine oil.
Incorrect oil clearance in crankshaft bearing - Bearing replacement required.
Oil pump is worn or damaged - Repair or replace.

Engine knocking or noise
Engine oil insufficient - Check oil level and add oil as required.
Low coolant temperature - Warm up engine as required.
Improper fuel injection timing - Adjust as recommended.
Incorrectly adjusted low idle speed - Need to adjust idle speed.
Dirty or defective injectors - Clean fuel injectors or change it.
Faulty or misaligned connecting rod - Need to align or replace the connecting rod.
Pistons are worn or broken - Replace the pistons as required.

Drive System Troubleshooting

Machine will not move forward or backward
Hydraulic oil level is low - Check and refill the hydraulic oil.
Drive chain malfunction - Check drive chain and change defective components.
Damaged input drive shaft - Replace drive shaft.
Defective relief valve - Repair or replace relief valve.
Plugged hydraulic filter or suction line - Service suction line or change hydraulic filter.
Foot or hand controls are defective - Replace or repair.
Drive pump or motor is damaged - Check and repair if required.

Low power
Hydraulic oil filter is clogged - Change or clean hydraulic filter.
Relief valve is open or worn - Replace or close relief valve.
Transmission components are damaged or faulty - Inspect and change defective parts.
Input drive shaft failure - Faulty drive shaft need to be replaced or repair.
Air leaks in hydraulic system - Bleed air from system.

Overheated drive system
Hydraulic fluid is insufficient - Add fluid as required.
Hydraulic fluid filter is dirty - Replace hydraulic filter.
Relief valver is broken - Change or repair defective relief valve.
Worn hydraulic motor or drive pump - Change or repair faulty component.
Clogged hydraulic oil cooler - Clean the cooling fins.
Drive system overload - Reduce drive system load.

Excessive noise
Incorrect oil viscosity - Use proper oil viscosity.
Air leaks in hydraulic system - Bleed hydraulic system.
Hydraulic motor or drive pump is worn - Replace or repair faulty component.
Worn or damaged mechanical components of drive system - Check drive system and change faulty components.

Hydraulics Troubleshooting

Hydraulic system is overheated
Hydraulic pressure is not adjusted correctly - Correct adjustment is required.
Faulty or improperly adjusted main relief valve - Set up or change the relief valve.
Hydraulic oil is contaminated - Hydraulic oil change required.
Hydraulic fluid level is insufficient - Fill the hydraulic system with oil.
Hydraulic pump is faulty - Replace or repair pump if necessary.

Lift arm won't raise or lower
Lift controls are faulty - Replace or repair.
Hydraulic pump not working - Change or repair hydraulic pump if required.
Defective hydraulic control valve - Repair or change hydraulic valve.
Faulty hydraulic cylinder - Change or repair lift cylinder.
Hydraulic oil is insufficient - Need to add oil.

Bucket does not tilt
Damaged bucket controls - Replace or repair.
Hydraulic pump malfunction - Install new pump or repair it.
Defective hydraulic control valve - Repair or replace the valve.
Bucket cylinder malfunction - Change or repair cylinder.
Hydraulic fluid is insufficient - Fill up the hydraulic fluid.

Boom or bucket functions slowly
Hydraulic pump is defective - Check pump capacity and change if necessary.
Oil leaks from hydraulic cylinder - Change cylinder piston seals.
Insufficient hydraulic fluid - Add fluid as required.
Hydraulic control valve is defective or set improper - Repair or set correctly.
Hydraulic system loosing pressure - Set pressure correctly.

Bucket or boom is working jerkily
Air in hydraulic system - Need to bleed air.
Hydraulic oil filter clogging - Replace or clean the filter.
Contaminated hydraulic oil - The oil must be changed.
Cylinder rod or tube is scuffed - Change defective component.

Hydraulic pump is noisy
Hydraulic leaks or lack of oil - Repair hydraulic leaks or add oil as required.
Hydraulic filter is dirty - Clean or change the filter.
Clogged suction line - Suction line must be serviced.
Pump sucks air - Bleed air.
Faulty pump parts - Rebuild or replace hydraulic pump.

Electrical Troubleshooting

Battery will not charge
Wiring connections are loose or corroded - Tighten or clean electrical wiring connections.
Battery terminal connectors are defective - Install new terminal connectors.
Battery failing - Install a new battery.
Belt is worn or loose - Change belt or adjust belt tension.

Starter cranks slowly
Battery power is low - Low battery charging, charge as required.
Battery is not holding charge - Service charging system or change battery.
Disconnected battery cables or bad terminals - Connect cables properly or replace terminals.

Starter motor is not working
Battery is discharged or defective - Charge or change the battery.
Battery wires are disconnected or incorrectly connected - Check wires and connect correctly.
Low battery output - Recharge the battery.
Faulty starter motor - Replace or repair starter.