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Caterpillar 918M Troubleshooting

The Caterpillar 918M compact wheel loader is powered by Caterpillar C4.4 ACERT 4-cylinder turbocharged aftercooled diesel engine with a rated power of 112 hp (83 kW) at 2200 rpm. The Cat 918M is equipped with a hydrostatic transmission, power steering system, hydraulic wet disc brakes, and 17.5x25 standard tires. The hydraulic system has a pump with fluid flow rate of 25 gpm (95 lpm). The hydraulic pressure is 4060 psi (280 bar). The wheel loader has a rated operating capacity of 6785 lbs (3080 kg) and tipping load of 13570 lbs (6160 kg). The max lift height is 150.4 inches (3820 mm) to hinge pin, and boom breakout force is 20090 lbs (9110 kg).

Engine Troubleshooting

Engine starts up hard or won't start
Air in the fuel pipes - Bleed the fuel pipes.
Fuel filter element is clogged - Service or replace the filter.
Burnt or defective injection nozzle - Clean or change injection nozzles.
Water or dirt in fuel system - Drain, flush, and service the system.
The valve clearance is not adjusted - Adjustment procedure required.
Fuel injection pump malfunctioning - Rebuild or install a new injection pump.

Diesel starts and stalls immediately
Air filter is clogged - Clean or replace element.
Fuel filter plugged - Replace the filter element.
Fuel injection pump has loose connections - Tighten the connections.
Damaged or clogged injectors - Change or clean fuel injectors.
Fuel injection pump is faulty - Replace or rebuild injection pump.

Engine stalls while running
Engine is not preheated - Warm up engine as required.
Fuel filter element is clogged - Change the filter element.
Air in fuel tank - Bleed fuel tank.
Defective injection nozzle - Check and replace nozzles if required.
Incorrect adjustment of fuel injection pump timing - Set up as recommended.

Engine stalling at idle
Low idle speed adjustment is incorrect - Adjust the low idle speed.
Fuel injection pump is damaged - Repair or install a new fuel pump.
Fuel injector fault - Change or clean fuel injectors.
Valve clearance is not correct - Correct valve clearance needs to be set.

Engine lacks power
Clogged air cleaner - Clean or replace air cleaner element.
Dirty or faulty injection nozzles - Test injection nozzles and change if necessary.
Fuel injection pressure is incorrect - Test fuel injection pressure and adjust it correctly.
Improper valve clearance - Need to adjust valve clearance.
Incorrectly set low idle speed - Adjustment required.
Dirt in the fuel lines or hoses - Clean fuel system hoses and lines.
Damaged cylinder-head gasket - Change cylinder head gasket.
Worn or damaged piston rings - Replace piston rings.

Engine is overheated
Insufficient coolant - The cooling system needs to be refilled and checked for faults.
Engine oil level is low - Checking oil level and add if necessary.
Faulty radiator cap or dirty radiator fins - Install new cap or clean radiator.
Damaged or worn fan belt - Change the fan belt.
Engine is under excessive load - Load reducing is recommended.

Oil pressure too low
Engine oil insufficient - Check oil level and add oil as required.
Engine oil filter is plugged - Change or clean engine oil filter element.
Incorrect engine oil Use proper viscosity oil.
Incorrect oil clearance in crankshaft bearing - Change bearings.
Oil pump malfunction - Repair or replace.

Engine noises or knocks
Engine oil level low - Fill up the oil to required level.
Engine is cold - Normalize the temperature by warming up the engine.
Wrong setting of fuel injection pump timing - Adjust fuel injection pump as required.
Too low idle RPM - Need to adjust idle speed.
Damaged or clogged injectors - Replace fuel injectors.
Connecting rod is defective or misaligned - Align or replace connecting rod.
Broken or worn pistons - Have pistons replaced.

Hydrostatic Transmission Troubleshooting

Excessive hydrostatic transmission noise
Transmission oil is contaminated or oil level is insufficient - Add oil to the correct level or fill the transmission with fresh oil.
Worn or unadjusted speed control linkage - Replace or adjust linkage.
Relief valve malfunction - Change the valve.
Transmission overloaded - Reduce loading.
Transmission parts are worm or defective - Change or repair defective parts.

Lack of power
Low oil level - Fill up the transmission oil.
Relief valve failure - Install a new relief valve.
Speed control linkage is worn or unadjusted - Adjust or repair linkage.

Transmission fluid overheated
Transmission fluid level is low - Add fluid to the transmission housing.
Dirty transmission oil filter element - Clean or replace the transmission filter.
Cooling components are clogged or damaged - Check all cooling components and repair or change if required.
Transmission overload - The load should be reduced.

Transmission oil leakage
Worn seals or gaskets - Gaskets or seal replacement required.
Transmission case internal pressure is too high - Check hydrostatic transmission components for defect or damage and change if necessary.
Oil drain pipe is plugged - Check pipe and service if necessary.

Hydraulics Troubleshooting

Hydraulic system overheating
Hydraulic pressure is not adjusted correctly - Adjust pressure as required.
Misadjusted or defective main relief valve - Adjust relief valve or change if required.
Hydraulic fluid is dirty - The fluid must be changed.
Not enough hydraulic fluid in the system - Need to add fluid.
Faulty hydraulic oil pump - Change or repair hydraulic pump if required.

Boom won't lower or raise
Damaged lift controls - Check and repair as required.
Hydraulic pump malfunction - Repair or change pump if required.
Hydraulic control valve failure - Replace or repair the valve.
Broken hydraulic cylinder - Replace or repair boom cylinder.
Hydraulic oil level low - Checking hydraulic oil level and add if necessary.

Bucket can't tilt
Bucket tilt controls are damaged - Inspect and repair if necessary.
Damaged hydraulic oil pump - Install new pump or repair it.
Faulty hydraulic control valve - Repair or change the valve.
Hydraulic bucket cylinder is defective - Repair or replace cylinder.
Insufficient hydraulic oil - Need to add oil.

Bucket or lift arm moves slowly
Worn hydraulic oil pump - Test the pump flow rate and install new pump if required.
Oil leaks from hydraulic cylinder - Install new cylinder seals.
Hydraulic fluid is insufficient - Checking hydraulic fluid level and add if necessary.
Hydraulic control valve is defective or set improper - Adjust correctly or repair.
Hydraulic pressure loss - Hydraulic pressure must be set correctly.

Bucket or boom jerks when working
Air trapped in hydraulic system - Bleed air from hydraulic system.
Hydraulic oil filter is clogged - Change or clean oil filter.
Hydraulic oil is dirty - Fill up with fresh hydraulic oil.
Cylinder rod or tube is scratched - Replace worn component.

Hydraulic pump is noisy
Not enough oil or hydraulic system leaking - Add hydraulic oil or correct system leaks.
Dirty hydraulic filter - Clean or replace the filter.
Dirty suction line - Suction line needs to be cleaned.
Pump sucks air - Bleed air from hydraulics.
Faulty pump components - Install new hydraulic pump or rebuild it.

Electrical Troubleshooting

Battery will not charge
Electrical cable connections are loose or corroded - Tighten or service connections.
Battery terminal clamps are defective - Replace terminal clamps.
Battery failing - Battery replacement required.
Loose or damaged belt - Adjust belt tension or install a new belt.

Starter turns slowly
Battery capacity is low - Battery is drained, charge it.
Battery discharges quickly - Service or replace the battery.
Battery terminals are corroded or wires are disconnected - Check cable connections and replace or service terminals.

Starter is not working
Battery is low or faulty - Recharge or replace battery.
Wire harness is disconnected or incorrectly connected - Check wire harness and connect as required.
Battery power is low - Charge the battery.
Defective starter motor - Starter needs to be replaced.

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WHEEL LOADERS SPECIFICATIONS

Caterpillar