________________________________________________________________________________________
| Home / Farm Tractors / Case IH Tractors / Case IH 785XL |
Case IH 785 XL Troubleshooting
The
Case IH 785 XL is a 2WD or 4WD utility tractor from 85XL-series. This model was
manufactured from 1985 to 1990. The Case IH 785XL tractor is powered by 246
cu.in (4 L) International D246 4-cylinder direct injection diesel engine with a
rated power of 77 hp (57.4 kW).
The tractor is fitted with a two transmission options: 16x8 semi-powershift transmission or 8x4 synchronized transmission. The maximum travel speed (forward/reverse): 21.1 mph (34 km/h) and 10.8 mph (17.4 km/h). The open center hydraulic system has a gear pump with a rated capacity of 12.4 gpm (46.9 lpm).
The hydraulic system pressure is 180 bar (2600 psi). The 2WD models are equipped with 10.00x16 front tires and 16.9x34 rear tires. The 12.4x24 front tires and 16.9x34 rear tires are used for 4WD tractors. The wheelbase is 88.2" (2240 mm) for 2-wheel drive tractors and 85.4" (2160 mm) for 4-wheel drive tractors.
| Engine Troubleshooting |
| Engine difficult to start or doesn't start |
Air in fuel tank - Bleed fuel tank.
Fuel filter plugged - Filter maintenance required.
Damaged or dirty injection nozzles - If necessary, replace with a new nozzle.
Water or dirt in fuel system - Drain, flush, and service the system.
Improper valve clearance - Have it adjusted.
Fuel injection pump is broken - Replacement or repair required.
| Engine starts but immediately stalls |
Air filter clogged - Change air filter element.
Fuel filter plugged - Clean or change the filter.
Poor fuel injection pump tightness - Look for any leaks of fuel pump Tighten it fast.
Fuel injector fault - Change or clean fuel injectors.
Faulty fuel injection pump - Install a new pump or rebuild.
| Diesel shuts off while driving |
Engine is cold - Normalize the temperature by warming up the engine.
Dirty fuel filter - Service or replace the filter.
Air in fuel tank - Bleed fuel tank.
Defective injection nozzle - Clean or replace injection nozzles.
Timing of fuel injection pump is incorrect - Use the correct fuel injection pump timing adjustment.
| Engine stalls while idling |
Low idle speed adjustment is incorrect - Adjust low idle speed.
Fuel injection pump is not working correctly - Replacement or repair required.
Dirty or defective injectors - Test and replace fuel injectors if necessary.
Valve clearance is not correct - Adjust valve clearance.
| Engine is not running at maximum power |
Plugged air cleaner - Install new air filter element.
Clogged or burnt injection nozzle - Test injection nozzles and change if necessary.
Fuel injection pressure is wrong - Adjust to proper pressure.
Valve out of adjustment - Correct valve clearance.
Low idle speed adjustment is incorrect - Test and adjust.
Clogged fuel lines or hoses - Clean fuel lines and hoses.
Cylinder head gasket is blown - Install new cylinder head gasket.
Leaking or damaged piston rings - Replace piston rings.
| Engine overheats |
Engine coolant is insufficient - Add coolant fluid to cooling system and also check it for leaks.
Lack of engine oil - Need to add engine oil.
Clogged radiator core or damaged radiator cap - Install new cap or clean radiator.
Broken or loose fan belt - Replace as required.
Engine is overloaded - Reduce load or shift to lower gear.
| Insufficient oil pressure |
Oil level is insufficient - Fill crankcase to proper oil level.
Oil filter element clogging - Service or change engine oil filter element.
Oil grade or viscosity is wrong - Use the specified type of engine oil.
Main bearing oil clearance is excessive - Bearing needs to be changed.
Oil pump malfunction - Inspect and change as required.
| Engine knocking or noise |
Engine oil level low - Check and refill engine oil.
Engine not warmed up - Normalize the temperature by warming up the engine.
Improper fuel injection timing - Use the correct fuel injection pump timing adjustment.
Wrong adjustment of low idle speed - Correct the settings.
Defective fuel injectors - Clean fuel injectors or change it.
Connecting rod is not aligned or worn - Replace or align connecting rod.
Pistons are broken or worn - Have pistons replaced.
| Transmission Troubleshooting |
| Transmission fluid pressure is insufficient |
Insufficient transmission fluid - Fill the transmission housing to proper fluid level.
Clogged transmission oil filter element (if fitted) - Clean or replace the transmission filter.
Relief valve malfunction - Replace valve as required.
| Transmission is making noise |
Insufficient transmission oil - Check transmission oil level and add oil as required.
Transmission oil contamination - Transmission oil change required.
Damaged gears or incorrect backlash - Change the gears or set backlash properly.
Worn or damaged bearings - Change faulty bearings.
Damaged or worn gear shift forks - Replace defective shift forks.
Worn or stuck shaft splines - Change the shaft.
| Hard shifting |
Gear shift linkage is corroded or worn - Install a new gear shift linkage.
Shift forks are worn or bent - Change the shift forks.
Worn parts of the gear shifting mechanism - Change worn parts.
Malfunction or incorrect clutch adjustment - Clutch replacement or adjustment required.
| External oil leaks |
High transmission fluid level - Drain the excess fluid.
Broken seals or gaskets - Install new gaskets or seal.
| Hydraulics Troubleshooting |
| Insufficient hydraulic fluid pressure |
Insufficient hydraulic oil - Fill the system to proper hydraulic oil level.
Clogged hydraulic fluid filter - Clean or change hydraulic filter.
Faulty hydraulic pump - Install a new hydraulic fluid pump.
Incorrect setting hydraulic control valve block - Set correctly.
Hydraulic cylinder malfunction - Replace or repair hydraulic cylinder.
Leaking hydraulic lines - Check the hydraulic system and fix leaks.
| Hydraulic system overheats |
Main relief valve is damaged - Change relief valve.
Wrong hydraulic oil type - Fill up with the correct type of oil.
Hydraulic oil contamination - Change the oil.
Air in hydraulic system - Bleed air from hydraulic system.
| 3-point hitch fails to lift or lifts slowly |
Excessive load on hitch - Reduce hitch load.
Hydraulic fluid level low - Fill up the hydraulic fluid.
Dirty hydraulic fluid filter element - Replace hydraulic filter element or service if necessary.
Hydraulic pump is defective - Replace or repair hydraulic oil pump.
Main relief valve is defective - Relief valve replacement required.
Hydraulic control valve block is faulty - Install a new valve or repair it.
Defective hydraulic cylinder - Repair or replace hydraulic cylinder.
Suction line is loose or broken - Replace or repair.
| Hitch not lowering or hitch lowers slowly |
Incorrect setting hydraulic control valve block - Set correctly.
Hydraulic cylinder is broken - Repair or change hydraulic cylinder.
The hitch has not been adjusted - Adjust 3-point hitch as required.
Damaged lift arm shaft - Change the shaft.
| Hitch drop or lift is jerky |
Air in hydraulic lines - Bleed hydraulic lines.
Hydraulic oil contamination - Change the oil.
Defective hydraulic pump - Change or repair hydraulic fluid pump.
Damaged hydraulic spool valve - Install a new valve or repair it.
Defective hydraulic cylinder - Change or repair hydraulic cylinder.
| Steering Troubleshooting |
| Steering wheel is hard to turn |
Improperly assembled or defective steering column - Reassemble or change the steering column.
Air in steering system - Bleed the steering system.
Incorrect toe-in - Check toe-in and correct.
Uneven tire pressure - Inflate the tires properly.
Steering pump is faulty - Steering pump needs to be replaced or repaired.
Pump flow control valve is stuck or damaged - Replace or service control valve.
Low steering oil level - Fill up the steering oil.
| Excessive free play of steering wheel |
Steering column coupling or shaft is extremely worn out - Replace defective part.
Steering pump not working - Check the hydraulic steering pump and change if necessary.
Worn or loose steering linkage joints - Repair or change steering linkage.
| Tractor pulls to right or left |
Front tires are worn unevenly - Install new tires.
Not adjusted toe-in - Check and adjust toe-in.
Steering linkage joints are worn or loose - Check and change as required.
Improperly adjusted or defective front wheel bearings - Change or adjust the bearings properly.
| Electrical Troubleshooting |
| Battery will not charge |
Electrical wire connections are corroded or loose - Service or tighten cable connections.
Defective electrical terminal connectors - Install new terminal connectors.
Battery is worn - Replace the battery.
Belt is damaged or loose - Install a new belt or adjust belt tension.
| Starter turns slow |
Battery capacity is low - Low battery charging, charge as required.
Battery won’t hold charge - Service charging system or change battery.
Corroded battery terminals or disconnected wires - Check wiring connections and replace or clean terminals.
| Starter doesn't crank |
Battery is low or faulty - Charge or change the battery.
Wiring is improperly connected or disconnected - Check wiring and connect properly.
Low battery voltage - Battery needs to be recharged.
Defective starter motor - Repair or change starter.
________________________________________________________________________________________
________________________________________________________________________________________
| Farm Tractors Technical Specifications |