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Case IH 743 XL Troubleshooting

The Case IH 743XL is a 2WD or 4WD utility tractor. This model was manufactured from 1985 to 1989. The tractor is powered by 239 cu.in (3.9 L) IH D-239 4-stroke 4-cylinder liquid-cooled diesel engine with a rated power of 67 hp (50 kW).

The Case IH 743 XL is fitted with a two transmission options: IH-Total-synchron powershift transmission with 16 forward and 8 reverse gears, or synchromesh transmission with 8 forward and 4 reverse gears. The maximum travel speed (forward/reverse): 15.6 mph (25 km/h) and 10 mph (16.1 km/h). The open center hydraulic system has a gear pump with a rated capacity of 8.7 gpm (32.9 lpm).

The hydraulic system pressure is 175 bar (2540 psi). The 2WD models are equipped with 7.50x16 front tires and 16.9R30 rear tires. The 9.50R24 front tires and 16.9R30 rear tires are used for 4WD tractors. The wheelbase is 94.1" (2390 mm) for 2WD models and 92.5" (2340 mm) for 4WD models.

Diesel Engine Troubleshooting
Engine starts hard or won't start

Air in the fuel system - Air bleeding.
Fuel filter element clogging - Change the filter element.
Clogged injection nozzle - Install a new kit of correctly balanced nozzles.
Dirt or water in fuel system - Drain water or flush dirt from the system.
The valve clearance is incorrect - Adjust valve clearance.
Fuel injection pump is broken - Replacement or repair required.

Diesel starts but stalls suddenly

Air filter clogged - Clean or replace element.
Fuel filter element is dirty - Service the filter.
Problems with fuel injection pump tightness - Inspect fuel injection pump for leaks.
Defective fuel injectors - Test and replace fuel injectors if necessary.
Fuel injection pump is broken - Change pump or rebuild it.

Engine stops suddenly during operation

Engine not warmed up - Warm up the engine.
Clogged fuel filter - Change filter element.
Air in the fuel lines - Bleed the fuel lines.
Damaged or dirty injection nozzles - If necessary, replace with a new nozzle.
Improper fuel injection timing - Set up as recommended.

Engine stalls when idle

Improperly adjusted low idle speed - Correct low idle settings.
Faulty fuel injection pump - Replace injection pump or repair it.
Damaged or clogged injectors - Change or clean fuel injectors.
Excessive valve clearance - Check and adjust as required.

Engine is not running at maximum power

Dirty air filter element - Replace air filter element.
Dirty or damaged injection nozzles - Clean or change injection nozzles.
Improper fuel injection pressure - Test fuel injection pressure and adjust it correctly.
Excessive valve clearance - Need to adjust valve clearance.
Incorrect low idle speed adjustment - Adjustment required.
Restricted fuel lines or hoses - Clean fuel system hoses and lines.
Cylinder-head gasket is broken - Replace cylinder head gasket.
Damaged or leaking piston rings - Change piston rings.

Engine overheats

Lack of coolant in cooling system - The cooling system needs to be refilled and checked for faults.
Low engine oil level - Check oil level and add oil as required.
Defective radiator cap or clogged radiator fins - Install new cap or clean radiator.
Fan belt is worn or faulty - Belt change is required.
Diesel engine overloaded - Reduce load on the engine.

Low oil pressure

Low crankcase oil level - Check and refill the oil.
Dirty oil filter element - Clean or change engine oil filter.
Oil grade or viscosity is incorrect - Fill up with the proper oil viscosity.
Incorrect crankshaft bearing oil clearance - Bearing needs to be changed.
Oil pump is damaged - Check and replace if necessary.

Engine noises or knocks

Engine oil level is insufficient - Check oil level and add oil as required.
Coolant temperature is low - Normalize the temperature by warming up the engine.
Improper fuel injection timing - Set up as recommended.
Incorrect low idle speed adjustment - Correct low idle adjustment.
Clogged or defective injectors - Replace or clean fuel injectors.
Connecting rod is defective or not aligned - Alignment procedure or replacement is required.
Pistons are worn or scored - Replace the pistons as required.

Transmission Troubleshooting
Lack of transmission oil pressure

Transmission oil insufficient - Need to add transmission oil.
Dirty transmission fluid filter element (if equipped) - Service or replace the transmission fluid filter.
Defective relief valve - Change the valve.

Transmission is making noise

Low fluid level - Fill the transmission housing to proper fluid level.
Transmission fluid is contaminated - Transmission fluid change required.
Gears are defective or backlash is improper - Install new gears and set backlash correctly.
Bearings are broken or worn - Bearings need to be changed.
Damaged or worn gear shift forks - Replace defective shift forks.
Damaged or worn shaft splines - Replace the shaft.

Gear hard to shift

Gear shift linkage is rusty or worn - Shift linkage need to be replaced.
Shift forks are worn or bent - Shift forks need to be changed.
Worn gear shifting mechanism - Repair or change worn components if necessary.
Improperly adjusted or worn clutch - Adjust correctly or replace.

Transmission oil leakage

Transmission fluid level is exceeded - Excess fluid must be drained.
Seals or gaskets are worn - Gaskets or seal replacement required.

Hydraulic System Troubleshooting
Hydraulic fluid pressure is low

Hydraulic oil is insufficient - Fill the system to proper hydraulic oil level.
Hydraulic oil filter is clogged - Clean or replace the hydraulic filter.
Hydraulic pump is faulty - Change or repair hydraulic fluid pump.
Hydraulic spool valve block is not adjusted properly - The spool valve should be properly adjusted.
Broken hydraulic cylinder - Repair or install a new hydraulic cylinder.
Leaking hydraulic lines - Inspect the system for leaks and fix it.

Hydraulic system overheating

Main relief valve is faulty - Relief valve need to be replaced.
Incorrect hydraulic fluid type - Fill up with the proper type of fluid.
Hydraulic oil contamination - Change the oil.
There is air in the hydraulic system - Bleed hydraulic system.

3-point hitch fails to lift or lifts slowly

Excessive load on hitch - Reduce loading.
Insufficient hydraulic oil - Check and refill the hydraulic oil.
Hydraulic fluid filter element is clogged - Change hydraulic filter element or clean if necessary.
Hydraulic pump is faulty - Repair or replace hydraulic fluid pump.
Damaged main relief valve - Change relief valve.
Hydraulic control valve block is damaged - Replace or repair the valve.
Defective hydraulic cylinder - Replace or repair hydraulic cylinder.
Suction line is disconnected or broken - Replace or connect correctly.

3-point hitch does not lower or lowers very slowly

Hydraulic control valve is not set properly - Adjust properly.
Broken hydraulic cylinder - Repair or change hydraulic cylinder.
Misadjusted hitch - The 3-point hitch must be adjusted.
Hitch rock shaft is worn Change the shaft.

Hitch lifting or lowering is jerky

Air in hydraulic pipes - Bleed hydraulic pipes.
Hydraulic fluid is dirty - Hydraulic fluid change required.
Defective hydraulic pump - Replace or repair hydraulic fluid pump.
Hydraulic spool valve block is defective - Replace or repair the valve.
Faulty hydraulic cylinder - Replace or repair hydraulic cylinder.

Steering Troubleshooting
Difficult steering

Incorrectly assembled or damaged steering column - Reassemble the steering column correctly or change it.
Air in steering hydraulic system - Bleed the system of air.
Incorrect toe-in - Check toe-in and correct.
Front tyres wear unevenly - Change the tyres.
Steering pump is faulty - Repair or replace steering pump.
Stuck or damaged steering pump control valve - Flush or change flow control valve.
Lack of steering oil - Fill the steering system with oil.

Excessive steering wheel free play

Worn steering column coupling or shaft - Change defective component.
Steering pump not working - Steering pump needs to be replaced or repaired.
Loose or worn steering linkage parts - Repair or replace steering linkage.

Front wheels wander to left or right

Front tires are worn unevenly - Install new tires.
Incorrect toe-in - Check and adjust toe-in.
Loose or worn steering linkage components - Repair or change steering linkage.
Incorrectly adjusted or damaged front wheel bearings - Replace or adjust the bearings correctly.

Electrical System Troubleshooting
Battery won’t charge

Electrical cable connections are corroded or loose - Service or tighten connections.
Defective battery terminal connectors - Terminal connectors should be replaced.
Faulty cell in battery - Use a new battery.
Worn or loose belt - Belt needs to be adjusted or replaced.

Starter turning slow

Low battery output voltage - Low battery charging, charge as required.
Battery drains quickly - Service or replace the battery.
Wires are disconnected or battery terminals are corroded - Connect cables properly or replace terminals.

Starter motor won't turn

Battery is drained or defective - Charge or replace the battery.
Battery cables are disconnected or incorrectly connected - Check cables and connect as needed.
Low battery capacity - Low battery charging, charge as required.
Starter motor is defective - Repair or install a new starter.



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