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Massey Ferguson 491 Troubleshooting

Massey Ferguson 491 Diesel Engine Troubleshooting

Engine difficult to start or won't start: Fuel filter plugged. Service or replace the filter. Air in the fuel lines. Bleed the fuel lines. Defective injection nozzle. If necessary, replace with a new nozzle. Fuel injection pump failure. Rebuild or install a new injection pump.

Engine stalls during operation: Fuel injection pump timing is wrong. Set up as recommended. Fuel filter plugged. Install new filter element. Engine is not preheated. Warm up to required temperature.

Engine starts but then stalls: Clogged fuel filter. Install new filter element. Defective fuel injection pump. Replace or rebuild injection pump. Dirty air filter. Change air filter element.

Engine is overheated: Radiator core is clogged or radiator cap is leaking. Clean radiator or replace cap. Lack of coolant in cooling system. Fill the cooling system and check components for leaks or other faults. Excessive wear of the fan belt. Belt replacement is recommended. Engine oil level low. Fill up the engine oil.

Engine lacks power: Defective or clogged injection nozzle. Service or change injection nozzles. Restricted fuel hoses or lines. Clean fuel system hoses and lines. Air filter clogged. Change air filter element. Cylinder-head gasket is broken. Replace the gasket as required.

Abnormal engine noise or knocking: Engine is not preheated. Warm up engine as required. Engine oil level low. Check oil level and add oil as required. Wrong setting of fuel injection pump timing. Adjust the pump as required. Piston wear or scoring. Install new pistons. Connecting rod is misaligned or defective. Connecting rod needs to be replaced or aligned.

Engine stops while idling: Low idle speed set incorrectly. Correct low idle adjustment. Improper valve clearance. Adjust valve clearance. Fuel injection pump is not working correctly. Install a new fuel pump or repair.

Oil pressure too low: Lack of oil. Fill up the engine oil. Oil pump failure. Install a new pump. Oil filter is dirty. Clean or replace engine oil filter element.

Massey Ferguson 491 Transmission Troubleshooting

Transmission noises: Damaged gears or incorrect backlash. Change the gears or set backlash properly. Worn or damaged gear shift forks. Replace the shift forks. Shaft splines are worn or stuck. Replace the shaft. Transmission fluid insufficient. Need to add transmission fluid. Worn or broken bearings. Replace the bearings. Transmission fluid is contaminated. Transmission fluid change required.

Difficulty shifting gears: Gear shift linkage is worn or rusty. Install new shift linkage. Worn or unadjusted clutch. Clutch adjustment or replacement required. Shift forks are worn or bent. Shift forks need to be changed. Worn gear shifting mechanism. Repair or change worn components if necessary.

Low transmission pressure: Lack of transmission oil supply. Fill up the transmission oil. Plugged transmission oil filter (if equipped). Service or replace the transmission oil filter. Relief valve is damaged. Replace relief valve.

Transmission oil leaks: Seals or gaskets are worn. Install new gaskets or seal. Transmission fluid level is exceeded. Excess fluid must be drained.

Massey Ferguson 491 Hydraulics Troubleshooting

Hydraulic system overheats: Incorrect hydraulic oil type. Use the correct type of hydraulic oil. Contaminated hydraulic oil. Change hydraulic oil. Air trapped in hydraulic system. Bleed air from system. Defective main relief valve. Replace relief valve.

Low hydraulic fluid pressure: Low hydraulic fluid level. Add fluid as required. Clogged hydraulic oil filter. Hydraulic filter maintenance required. Leaks in hydraulic lines. Check the system and repair leaks. Not adjusted hydraulic control valve. Need to adjust. Faulty hydraulic pump. Change or repair hydraulic fluid pump. Hydraulic cylinder is broken. Install a new hydraulic cylinder or repair it.

3-point hitch won't lift or lifts slowly: Hydraulic pump is faulty. Repair or replace hydraulic fluid pump. Damaged main relief valve. Install a new relief valve. Faulty hydraulic spool valve. Repair or change hydraulic valve. Hydraulic cylinder is broken. Install a new hydraulic cylinder or repair it. Insufficient hydraulic fluid. Fill the system to proper hydraulic fluid level. Hydraulic oil filter element is clogged. Service the hydraulic filter or change if required. Heavy load on the hitch. Reduce hitch load.

Hitch fails to drop or drops slowly: Hydraulic cylinder malfunction. Repair or install a new hydraulic cylinder. Not adjusted hydraulic spool valve. Need to adjust spool valve. Hitch rock shaft is worn. Change the shaft. Unadjusted hitch. Adjust the hitch.

Hitch lift or drop is not smoothly: Contaminated hydraulic oil. Change hydraulic oil. Hydraulic pump failure. Install a new hydraulic fluid pump. Air in the hydraulic system. Air bleeding. Hydraulic control valve is defective. Install a new hydraulic valve or repair it. Broken hydraulic cylinder. Replace or repair hydraulic cylinder.

Massey Ferguson 491 Steering System Troubleshooting

Excessive steering wheel free play: Steering column shaft or coupling is worn out. Change faulty part. Steering pump failure. Install a new hydraulic steering pump. Steering linkage assembly is worn or loose. Check and change as required. Power steering control valve has damage or wear. Change or repair steering control valve if required.

Heavy steering: Air in the hydraulic steering system. Bleed the steering system. Clogged steering filter element. Clean or replace filter element. Low steering fluid level. Fill the steering system with fluid. Power steering control valve is damaged or worn. Change or repair steering control valve. Hydraulic steering pump is defective. Steering pump needs to be replaced or repaired. Pump flow control valve is damaged or stuck. Flush or change flow control valve. Improperly fitted or damaged steering column. Refit or change the steering column. Uneven wear on front tyres. Replace the tyres. Not adjusted toe-in. Adjust toe-in wheels. Leaking steering cylinder. Change worn piston seals or damaged piston rod.

Front wheels wander to left or right: Power steering control valve is damaged or worn. Change or repair steering control valve if required. Defective steering cylinder. Repair or change hydraulic steering cylinder. Not adjusted toe-in. Adjust toe-in wheels. Steering linkage parts are loose or worn. Repair or replace steering linkage. Incorrectly adjusted or damaged front wheel bearings. Adjust correctly or replace bearings. Uneven tyre pressure. Inflate the tyres properly.

Massey Ferguson 491 Electrical System Troubleshooting

Battery cannot be charged: Corroded or loose electrical wire connections. Tighten or service cable connections. Defective battery terminal connectors. Replace terminal connectors. Battery is defective. Install a new battery. Damaged or loose belt. Replace belt or adjust belt tension.

Starter turns slow: Low battery voltage. Battery needs to be recharged. Battery discharges quickly. Service charging system or replace battery. Disconnected cables or faulty battery terminals. Connect wiring correctly or install new terminals.

Starter will not work: Battery is low or faulty. Recharge or replace battery. Wiring is incorrectly connected or disconnected. Inspect wiring and connect correctly. Low battery power. Battery is drained, recharge it. Defective starter motor. Repair or change starter.