Gehl 6625SX Skid Steer Troubleshooting

The Gehl 6625 SX skid steer loader is powered by 183 cu.in (3L) Perkins 204.30 4-cycle vertical 4-cylinder liquid-cooled diesel engine with a rated power of 70 hp (52 kW) at 2600 rpm. The Gehl 6625SX is equipped with 1-speed hydrostatic transmission, radial-lift loader boom, 80H roller chains, and 12x16.5 or 31-15.5x15 tires. The hydraulic system has a pump with fluid flow rate of 23 gpm (87.1 lpm). The hydraulic pressure is 3000 psi (207 bar). The skid steer loader has a rated operating capacity of 2050 lbs (930 kg) and tipping load of 4100 lbs (1860 kg). The lift height is 123 inches (3125 mm) to hinge pin, and dump height is 98.8 inches (2510 mm).

Engine Troubleshooting

Engine starts hard or won't start

Air in the fuel lines - Bleed the fuel lines.
Fuel filter plugged - Change filter element.
Defective or clogged injection nozzle - Clean or change injection nozzles.
Water or dirt in fuel system - Drain, flush, and service the system.
Incorrect valve clearance - Adjust valve clearance according to specifications.
Fuel injection pump damage - Replace injection pump or repair it.

Diesel starts and then shuts off

Clogged air filter - Replace or clean air filter element.
Clogged fuel filter - Clean or replace the filter.
Fuel injection pump has loose connections - Tighten the connections.
Defective or clogged fuel injectors - Clean fuel injectors or change it.
Fuel injection pump is broken - Install a new fuel pump or repair.

Engine shuts off suddenly during operation

Low coolant temperature - Warm up the engine.
Fuel filter element is clogged - Replace the filter element.
Air trapped in fuel system - Bleed air.
Clogged or defective injection nozzles - Install a new kit of correctly balanced nozzles.
Fuel injection pump timing is wrong - Set it up as required.

Engine stops when idling

Low idle speed setting is not correct - Correct low idle adjustment.
Fuel injection pump is not operating properly - Replacement or repair required.
Fuel injectors are faulty or clogged - Clean or replace fuel injectors.
Valve clearance is wrong - Adjust valve clearance.

Engine power is insufficient

Dirty air filter - Install new air filter element.
Dirty or faulty injection nozzles - If necessary, replace with a new nozzle.
Fuel injection pressure is incorrect - Adjust pressure to proper level.
Excessive valve clearance - Adjust valve clearance.
Low idle speed adjustment is incorrect - Adjust low idling as recommended.
Fuel lines or hoses are clogged - Clean fuel system lines and hoses.
Cylinder head gasket is worn - Gasket should be replaced.
Leaking or damaged piston rings - Piston rings need to be replaced.

Engine is overheated

Lack of coolant in cooling system - Add coolant fluid and inspect the cooling system for leaks.
Insufficient engine oil - Check and refill engine oil.
Clogged radiator fins or leaking radiator cap - Clean radiator or replace cap.
Damaged or worn fan belt - If necessary, replace the belt.
Engine overloaded - Load reducing is recommended.

Insufficient oil pressure

Lack of oil - Add oil to the engine crankcase.
Clogged oil filter - Clean or change engine oil filter.
Oil grade or viscosity is wrong - Use oil of correct viscosity.
Incorrect crankshaft bearing oil clearance - Replace bearings.
Defective oil pump - Repair or change.

Engine knocking sound or abnormal noise

Engine oil level is insufficient - Check and refill engine oil.
Engine is cold - Warm up the engine.
Improper setting of fuel injection pump timing - Adjust fuel injection pump as required.
Incorrect low idle speed adjustment - Adjust low idling as recommended.
Dirty or defective injectors - Inspect fuel injectors and change as required.
Connecting rod is not aligned or defective - Align or change connecting rod.
Worn or broken pistons - Pistons need to be replaced.

Drive System Troubleshooting

Machine will not move forward or backward

Hydraulic fluid is insufficient - Check and refill the hydraulic fluid.
Faulty drive chain - Check drive chain and change faulty parts.
Damaged input drive shaft - Rebuild or change.
Defective relief valve - Rebuild or install a new relief valve.
Hydraulic filter or suction line is dirty - Clean suction line or replace hydraulic filter.
Defective hand or foot controls - Repair or replace.
Drive motor or pump is defective - Replace or repair faulty component.

Loss of power

Plugged hydraulic oil filter - Change hydraulic filter.
Relief valve is damaged or open - Close or replace relief valve.
Transmission components are worn or defective - Check and replace defective components.
Input drive shaft failure - Repair or install a new drive shaft.
Hydraulic system is leaking air - Bleed air from system.

Overheated drive system

Hydraulic oil is insufficient - Checking hydraulic oil level and add if necessary.
Hydraulic fluid filter is dirty - Change hydraulic filter.
Relief valve defective or worn - Repair or replace.
Hydraulic motor or drive pump is defective - Replace or repair faulty component.
Dirty oil cooler - Cooling fins should be cleaned.
Transmission overloading - Reduce the load.

Drive system is excessively noisy

Oil viscosity is too heavy - Drain and refill with correct oil.
Air leaks in hydraulic system - Bleed air from hydraulic system.
Worn hydraulic motor or drive pump - Inspect and change as required.
Defective or worn mechanical components of drive system - Check drive system and change faulty components.

Hydraulics Troubleshooting

Hydraulic system overheats

Incorrect hydraulic pressure setting - Correct setting is required.
Main relief valve is damaged or adjusted improperly - Adjust or change relief valve.
Hydraulic oil contamination - Fill up with fresh hydraulic oil.
Lack of hydraulic fluid - Fill the hydraulic system with oil.
Faulty hydraulic oil pump - Replace or repair pump if necessary.

Boom won't lower or raise

Damaged lift controls - Check and repair as required.
Hydraulic pump not working - Change or repair hydraulic pump if required.
Hydraulic control valve failure - Repair or replace the valve.
Hydraulic cylinder is defective - Repair or change hydraulic cylinder.
Hydraulic oil is insufficient - Check and refill the hydraulic oil.

Bucket can't tilt

Bucket tilt controls malfunction - Repair or replace.
Hydraulic pump not working - Replace or repair pump if necessary.
Damaged hydraulic control valve - Install a new hydraulic valve or repair it.
Bucket cylinder is faulty - Repair or install a new cylinder.
Low hydraulic fluid level - Add fluid as required.

Boom or bucket moves slowly

Faulty hydraulic oil pump - Test pump performance and replace pump if necessary.
Hydraulic cylinder oil leakage - Repair leak by replacing the seals.
Hydraulic fluid level low - Fill up the hydraulic fluid.
Defective or not adjusted hydraulic control valve - Repair or set properly.
Low hydraulic pressure - Adjust it correctly.

Lift arm or bucket is jerky

Air leaks in hydraulic system - Bleed air from hydraulic system.
Dirty hydraulic oil filter - Clean or install new filter.
Contaminated hydraulic oil - Fill up with fresh hydraulic oil.
Scratched cylinder rod or tube - Change worn component.

Excessive hydraulic pump noise

Hydraulic leakage or low oil level - Correct hydraulic leaks or top up oil as needed.
Hydraulic filter clogging - Change or clean oil filter.
Dirty suction line - Service the suction line.
Pump sucks air - Remove air from hydraulics.
Pump components are damaged - Rebuild or replace hydraulic pump.

Electrical Troubleshooting

Battery does not charge

Electrical cable connections are loose or corroded - Service or tighten cable connections.
Defective electrical terminal connectors - Change terminal connectors.
Battery bad cell - Use a new battery.
Belt is loose or defective - Adjust belt tension or install a new belt.

Starter motor cranks slow

Battery capacity is low - Battery is drained, charge it.
Battery is not holding charge - Battery needs to be serviced or replaced.
Disconnected wires or corroded battery terminals - Check cable connections and change or clean terminals.

Starter motor won't turn

Battery is low or faulty - Battery needs to be recharged or replaced.
Wiring harness is disconnected or improperly connected - Check wiring harness and connect as required.
Battery power is low - Recharge the battery.
Defective starter motor - Starter needs to be replaced.