Case 90XT Skid Steer Troubleshooting

The Case 90XT skid steer loader driveline system components: a 239 cu.in (3.9L) Case 4T-390 four-cylinder direct injection turbocharged diesel engine with a rated power of 85 hp (63.4 kW) and 2-speed hydrostatic transmission. The hydraulic system has a gear pump with a rated capacity of 20.3 gal/min (77 l/min). The system relief pressure is 3000 psi (207 bar). The Case 90XT is equipped with a planetary double reduction, 120HS continuous roller chains, and 12x16.5 tires. The skid steer has a boom lifting force of 5290 lbs (2405 kg) and bucket breakout force of 6200 lbs (2818 kg). The rated operating capacity is 2450 lbs (1110 kg), and tipping load is 4900 lbs (2220 kg).

Engine Troubleshooting

Engine starts up hard or doesn't start

There is air in the fuel system - Bleed the system.
Fuel filter element is dirty - Service the filter.
Burnt or clogged injection nozzle - Change fuel injection nozzles.
Water or dirt in fuel system - Drain, flush, and service the system.
Valve clearance is not correct - Have it adjusted.
Damaged fuel injection pump - Rebuild or install a new injection pump.

Engine starts but immediately stalls

Air cleaner is dirty - Clean or change cleaner.
Fuel filter element is clogged - Change or clean the filter element.
Fuel injection pump has loose connections - Tighten the connections.
Dirty or defective injectors - Change or clean fuel injectors.
Fuel injection pump damage - Replace or rebuild injection pump.

Engine stalls after running

Engine is not warmed up to required temperature - Warm up the engine as required.
Fuel filter element clogging - Install new filter element.
Air in the fuel lines - Bleed the fuel lines.
Clogged or defective injection nozzles - If necessary, replace with a new nozzle.
Wrong setting of fuel injection pump timing - Set it up as required.

Engine stalls at low idle speed

Incorrectly set low idle speed - Adjust low idling as recommended.
Fuel injection pump is not operating properly - Change or repair the pump.
Fuel injector fault - Test and replace fuel injectors if necessary.
Valve clearance is wrong - Need to adjust valve clearance.

Engine power loss

Clogged air filter - Install new air filter element.
Defective or clogged injection nozzle - Clean or change injection nozzles.
Insufficient fuel injection pressure - Test fuel injection pressure and adjust it correctly.
Valve clearance is out of adjustment - Check and adjust as required.
Low idle speed setting is not correct - Adjust the low idle speed.
Fuel lines or hoses are clogged - Fuel lines and hoses need to be cleaned.
Blown cylinder head gasket - Change cylinder head gasket.
Leaking or defective piston rings - Piston rings need to be replaced.

Engine overheated

Low engine coolant - Fill radiator to proper level and check components for faults.
Not enough engine oil - Fill up the oil to required level.
Dirty radiator fins or faulty radiator cap - Install new cap or clean radiator.
Fan belt is loose or defective - Replace as required.
Diesel engine is overloaded - Load reducing required.

Low oil pressure

Oil level is insufficient - Checking oil level and add if necessary.
Plugged engine oil filter - Replace or service engine oil filter.
Different type of engine oil - Use oil of proper viscosity.
Excessive main bearing oil clearance - Install new bearings.
Defective oil pump - Install a new pump.

Abnormal engine knocking or noise

Not enough engine oil - Add oil to the engine crankcase.
Low coolant temperature - Warm up the engine.
Improper setting of fuel injection pump timing - Check the fuel injection pump timing adjustment.
Incorrect low idle speed adjustment - Adjust as required.
Clogged or defective injectors - Test and replace fuel injectors if necessary.
Connecting rod is worn or not aligned - Align or replace connecting rod.
Pistons are broken or worn - Replace the pistons.

Drive System Troubleshooting

Machine is not moving forward or backward

Hydraulic fluid is insufficient - Add fluid as required.
Worn drive chain - Check drive chain and change faulty parts.
Input drive shaft failure - Service or change drive shaft.
Relief valve failure - Change or repair relief valve.
Plugged hydraulic filter or suction line - Change hydraulic filter or service suction line.
Defective hand or foot controls - Change or repair.
Drive motor or pump failure - Inspect and replace as necessary.

Loss of power

Dirty hydraulic oil filter - Change hydraulic filter.
Opened or defective relief valve - Close or replace relief valve.
Transmission components are faulty or damaged - Check and change defective components.
Damaged input drive shaft - Repair or replace faulty drive shaft.
Air in the hydraulic system - Need to bleed air.

Drive system overheats

Hydraulic oil is insufficient - Need to add oil.
Plugged hydraulic fluid filter - Check, clean, or replace as required.
Defective or worn relief valve - Service or change relief valve.
Damaged drive pump or hydraulic motor - Inspect and replace as necessary.
Hydraulic oil cooler is dirty - Cooling fins should be cleaned.
Transmission overloading - Load should be reduced.

Drive system makes excessive noise

Improper oil viscosity - Use correct oil viscosity.
Air in hydraulic system - Bleed hydraulic system.
Worn hydraulic motor or drive pump - Change or repair faulty component.
Mechanical parts of drive system are damaged or worn - Check the components for defect or damage and change if necessary.

Hydraulics Troubleshooting

Hydraulic system overheats

Incorrect hydraulic pressure setting - Adjust pressure as required.
Main relief valve is defective or unadjusted - Replace or set up the relief valve.
Hydraulic fluid contamination - Fill up with fresh hydraulic fluid.
Hydraulic oil level is insufficient - Fill up the hydraulic oil.
Hydraulic pump is worn - Replace or repair pump if necessary.

Boom won't lower or raise

Defective lift controls - Check and repair as required.
Hydraulic pump failure - Repair or install new hydraulic pump.
Damaged hydraulic control valve - Repair or change the valve.
Hydraulic cylinder not working - Change or repair lift cylinder.
Hydraulic fluid is insufficient - Add fluid as required.

Bucket can't tilt

Defective bucket controls - Change or repair.
Damaged hydraulic oil pump - Repair or install new hydraulic pump.
Defective hydraulic control valve - Change or repair hydraulic valve.
Faulty hydraulic bucket cylinder - Replace or repair cylinder.
Low hydraulic oil level - Need to add oil.

Boom or bucket runs slowly

Worn hydraulic oil pump - Check hydraulic pump flow and replace pump if necessary.
Oil leaks from hydraulic cylinder - Replace cylinder piston seals.
Low hydraulic oil level - Checking hydraulic oil level and add if necessary.
Faulty or incorrect setting hydraulic control valve - Repair or set properly.
Hydraulic system loosing pressure - Set pressure correctly.

Bucket or boom movements are jerky

Air in hydraulic system - Need to bleed air.
Plugged hydraulic oil filter - Clean or install new filter.
Hydraulic fluid is dirty - The fluid must be changed.
Cylinder rod or tube is scuffed - Change damaged component.

Hydraulic pump makes excessive noise

Insufficient oil level or leaking hydraulic system - Repair hydraulic leaks or add oil as required.
Clogged hydraulic filter - Replace or clean the filter.
Suction line clogging - Clean suction line as required.
Air enters the pump - Remove air from hydraulics.
Worn pump parts - Rebuild or install new pump.

Electrical Troubleshooting

Battery does not charge

Electrical wire connections are loose or corroded - Tighten or clean connections.
Defective battery terminal clamps - Terminal clamps need to be replaced.
Defective battery - Use a new battery.
Loose or defective belt - Belt needs to be adjusted or replaced.

Starter motor turns slow

Low battery output - Low battery charging, charge as required.
Battery drains quickly - Service battery or replace it.
Battery cables are disconnected or terminals are faulty - Check cables and service or change terminals.

Starter doesn't crank

Battery is discharged or defective - Battery needs to be recharged or replaced.
Wire harness is disconnected or incorrectly connected - Check wire harness and connect as required.
Battery voltage is low - Battery needs to be recharged.
Starter motor failure - Starter needs to be replaced.