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Mustang 4000V Troubleshooting

The Mustang 4000V skid steer loader is powered by 273 cu.in (4.5L) Cummins QSB4.5 four-stroke four-cylinder vertical in-line turbocharged liquid-cooled diesel engine with a rated power of 99 hp (74 kW) at 2200 rpm. The Mustang 4000V is equipped with a vertical-lift loader boom, two-speed hydrostatic transmission, 100H drive chains, and 14x17.5 HD standard tires. The hydraulic system has a pump with fluid flow rate of 32 gpm (121 lpm) or 40.8 gpm (154 lpm). The skid steer loader has a rated operating capacity of 4000 lbs (1814 kg) and tipping load of 8000 lbs (3630 kg). The lift height is 143.6" (3645 mm) to hinge pin, and dump height is 114.8" (2915 mm).

Engine Troubleshooting

Engine starts hard or won't start
There is air in the fuel system - Bleed the system.
Clogged fuel filter - Clean or replace the filter.
Dirty or faulty injection nozzles - Replace injection nozzles.
Water in the fuel system - Change fuel and repair fuel system.
Valve clearance is out of adjustment - Adjustment procedure required.
Fuel injection pump is defective - Change pump or rebuild it.

Diesel starts and suddenly stops
Air filter is dirty - Install new air filter element.
Fuel filter plugged - Change or clean the filter element.
Fuel injection pump leakage - Check the fuel injection pump for leaks and fix it.
Clogged or defective injectors - Replace or clean fuel injectors.
Fuel injection pump failure - Change or repair the pump.

Engine shuts off suddenly during operation
Coolant temperature is low - Warm up to required temperature.
Fuel filter is plugged - Change filter element.
There is air in the fuel system - Bleed the system.
Clogged or defective injection nozzles - Change fuel injection nozzles.
Wrong setting of fuel injection pump timing - Adjust fuel injection pump as required.

Engine stops while idling
Incorrectly adjusted low idle speed - Correct low idle settings.
Fuel injection pump is not operating properly - Repair or install new pump.
Fuel injector fault - Clean fuel injectors or change it.
Valve clearance is wrong - Check and adjust as required.

Diesel engine loses power
Plugged air cleaner - Service or replace air cleaner.
Fuel injection nozzles are faulty or clogged - Replace injection nozzles.
Incorrect fuel injection pressure - Adjust to correct pressure.
Valve clearance is wrong - Adjustment procedure required.
Incorrectly set low idle speed - Adjust low idle speed.
Restricted fuel hoses or lines - Service fuel hoses and lines.
Cylinder head gasket is worn - Install a new gasket.
Piston rings are leaking or defective - Install new piston rings.

Engine is overheated
Coolant level is low - Fill radiator to proper level and check components for faults.
Not enough engine oil - Add oil to the engine crankcase.
Dirty radiator fins or faulty radiator cap - Install new cap or clean radiator.
Excessive wear of the fan belt - Change as required.
Engine overload - Load reducing is recommended.

Oil pressure too low
Low oil level - Need to add oil.
Oil filter is clogged - Clean or replace engine oil filter element.
Improper type of engine oil - Drain crankcase and refill with correct oil.
Excessive crankshaft bearing oil clearance - Change bearings.
Oil pump malfunction - Repair or replace.

Engine knocks or noises
Low engine oil level - Fill up the oil to required level.
Engine is not fully warmed up - Warm up the engine.
Improper setting of fuel injection pump timing - Set up as recommended.
Low idle speed setting is not correct - Adjust as required.
Fuel injector fault - Change or clean fuel injectors.
Connecting rod failure or misalignment - Connecting rod needs to be replaced or aligned.
Pistons are worn or broken - Pistons need to be replaced.

Drive System Troubleshooting

Drive system doesn't function in one direction or either direction
Insufficient hydraulic fluid - Fill up the hydraulic fluid.
Drive chain failure - Check drive chain and change faulty components.
Faulty relief valve - Change or repair relief valve.
Plugged suction line or hydraulic filter - Check, clean, or replace if required.
Foot or hand controls are damaged - Inspect and repair if necessary.
Defective drive pump or motor - Change or repair faulty component.

Loss of power
Hydraulic oil filter is plugged - Check, clean, or change as necessary.
Defective or open relief valve - Close or change relief valve.
Transmission parts are damaged or faulty - Inspect and replace defective parts.
Input drive shaft is damaged - Replace drive shaft.
Hydraulic system is leaking air - Need to bleed air.

Overheated drive system
Insufficient hydraulic oil - Need to add oil.
Plugged hydraulic fluid filter - Change or clean hydraulic filter.
Relief valve defective or worn - Repair or change.
Hydraulic motor or drive pump failure - Repair or replace faulty component.
Oil cooler is clogged - Cooling fins should be cleaned.
Overloaded drive system - Reduce loading.

Drive system makes excessive noise
Oil viscosity is too heavy - Use oil of proper viscosity.
Hydraulic system is leaking air - Air bleeding is required.
Hydraulic motor or drive pump is worn - Check and repair if required.
Mechanical parts of drive system are damaged or worn - Check the parts for worn or defect and replace if required.

Hydraulics Troubleshooting

Hydraulic system has overheating
Hydraulic pressure is not correct - Adjust pressure correctly.
Main relief valve improper adjustment or failure - Set up or change the relief valve.
Dirty hydraulic oil - The oil must be changed.
Hydraulic oil level is insufficient - Fill up the hydraulic oil.
Worn hydraulic oil pump - Repair or install new hydraulic pump.

Lift arm does not lower or raise
Damaged lift controls - Change or repair.
Damaged hydraulic oil pump - Install new pump or repair it.
Damaged hydraulic control valve - Repair or replace hydraulic valve.
Damaged hydraulic cylinder - Repair or replace hydraulic cylinder.
Hydraulic fluid level low - Checking hydraulic fluid level and add if necessary.

Bucket can't tilt
Damaged bucket controls - Inspect and repair if necessary.
Hydraulic pump is broken - Change or repair hydraulic pump if required.
Faulty hydraulic control valve - Install a new hydraulic valve or repair it.
Faulty hydraulic bucket cylinder - Install a new cylinder or repair it.
Insufficient hydraulic oil - Check and refill the hydraulic oil.

Boom or bucket functions slowly
Hydraulic pump is worn - Check the pump performance and replace it if required.
Leaking hydraulic cylinder - Repair leak by replacing the seals.
Insufficient hydraulic fluid - Checking hydraulic fluid level and add if necessary.
Worn or unadjusted hydraulic control valve - Set correctly or repair.
Hydraulic pressure is low - Correct setting is required.

Lift arm or bucket jerks when working
Air in the hydraulic system - Air bleeding is required.
Plugged hydraulic oil filter - Clean or replace the filter.
Dirty hydraulic oil - Fill up with fresh hydraulic oil.
Scratched cylinder rod or tube - Change failed component.

Hydraulic pump makes excessive noise
Lack of oil or hydraulic leakage - Add hydraulic oil or correct system leaks.
Plugged hydraulic filter - Service or replace hydraulic filter.
Suction line clogging - Suction line must be serviced.
Air enters the pump - Remove air from hydraulics.
Worn pump parts - Rebuild or install new pump.

Electrical Troubleshooting

Battery does not charge
Electrical cable connections are loose or corroded - Tighten or service cable connections.
Faulty battery terminal clamps - Terminal clamps need to be replaced.
Battery failing - Use a new battery.
Belt is damaged or loose - Belt needs to be adjusted or changed.

Starter motor turns slow
Low battery output - Battery needs to be recharged.
Battery runs out quickly - Battery needs to be serviced or replaced.
Bad battery terminals or disconnected wiring - Connect wiring properly or install new terminals.

Starter doesn't crank
Battery is discharged or defective - Recharge or change battery.
Wiring is incorrectly connected or disconnected - Inspect wiring and connect correctly.
Low battery voltage - Recharge the battery.
Starter motor is defective - Starter should be replaced.