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Ford 7700 Tractor Troubleshooting
The
Ford 7700 row-crop tractor was manufactured between 1975 and 1981. The Ford 7700
is powered by Ford 256 4-cycle four-cylinder liquid-cooled diesel engine with a
maximum power of 96.7 Hp (72.1 kilowatt) and 369 Nm (272 lb-ft) of peak torque
at 1600 rpm.
The Ford 7700 tractor is equipped with two types of transmission. 1st
type: 16x4 Dual-Power transmission. 2nd type: 8x2 Dual-Range gear
transmission. The max. forward speed - 18.6 mph (30 km/h), a max.
reverse speed - 9 mph (14.5 km/h).
The open center hydraulic system used a gear pump with flow rate of 9.7
gpm (36.9 lpm). The hydraulic system pressure is 172.5 bar (2500 psi).
The Ford 7700 is fitted with 7.50x18 front tires and 18.4x34 rear tires.
The wheelbase is 101.6 in (2580 mm). The tractor is compatible with two
front end loader models. The Ford 774 loader has a lift capacity to full
height of 2000 lbs (907 kg). The Ford 772QT loader has a lift capacity
to max height of 2500 lbs (1134 kg).
Engine Troubleshooting |
Engine will not start or hard to start |
Fuel filter plugging - Install new filter element |
Fuel supply valve is closed - Open fuel supply valve |
Fuel-line is leaking air - Retighten clamps, replace defective pipes |
Fuel injectors are damaged or dirty - Service or change fuel injectors |
Fuel injection pump is broken - Rebuild or replace pump |
Poor cylinder compression - Inspect cylinder block and change worn parts |
Engine stops running unexpectedly |
Engine is not fully warmed up - Warm up engine as required |
Fuel-line is leaking air - Retighten clamps, replace defective pipes |
Irregular fuel injection - Adjust fuel injection timing |
Fuel filter plugging - Service the filter |
Fuel injectors are damaged or dirty - Service or change fuel injectors |
Diesel starts but then stalls |
Timing of fuel injection pump is not adjusted - Check the fuel injection pump timing setting |
Dirty fuel filter element - Change filter element |
Clogged or damaged injector nozzles - Install a new set of well-balanced nozzles |
Damaged fuel injection pump - Repair or install a new fuel pump |
Air cleaner element clogging - Replace cleaner or install new cleaner element |
Engine stops while idling |
Low idle speed adjustment is incorrect - Adjustment required |
Fuel injection pump failure - Install a new pump or rebuild |
Fuel injector nozzles are dirty or defective - Test injector nozzles and replace as required |
Incorrect valve clearance - Correct valve clearance |
Coolant level is low - Refill to the correct level. Check system for leaks |
Cooling system parts are damaged or system is dirty - Replace faulty parts or flush the cooling system |
Engine oil level is low - Check oil level and add oil as required |
Worn fan belt or incorrect belt tension - Adjust belt tension properly or change it |
Defective or wrong type of thermostat - Check and replace if required |
Fuel injectors are clogged or faulty - Change fuel injectors |
Incorrect fuel injection pressure - Check the fuel injection pressure and adjust if necessary |
Clogged air filter element - Replace filter or install new filter element |
Oil filter clogging - Service or replace engine oil filter |
Engine overloaded - Load reducing is recommended |
The valve clearance is incorrect - Adjust to proper valve clearance |
Incorrectly adjusted low idle speed - Adjust low idle speed |
Restricted fuel hoses or pipes - Fuel pipes and hoses need to be cleaned |
Engine compression too low: Valves are faulty or leaking - Have valves replaced |
Timing of fuel injection pump is not adjusted - Correct injection timing |
Fuel injector nozzles are damaged - Replace fuel injector nozzles |
Engine oil insufficient - Add oil to the engine crankcase |
Engine is cold - Warm up engine to required temperature |
Crankshaft or main bearings failure - Crankshaft or bearings need to be replaced |
Damaged or defective piston rings - Piston rings replacement required |
Loose flywheel bolts - Inspect flywheel bolts and tighten properly |
High engine oil consumption |
External oil leaks: Gaskets or seals are excessively worn - Replace worn parts to avoid leaks |
Improper oil viscosity - Use proper viscosity oil |
Piston rings are defective or worn - Have piston rings replaced |
Valve guides and stems are worn - Valves must be replaced |
Cylinder liners or pistons are damaged - Inspect pistons and liners, change as required |
Electrical System Troubleshooting |
Battery is not charging |
Faulty cell in battery - Change the battery |
Battery electrical wire harness damage - Check battery wires for damage, replace or change |
Battery cables and terminals are corroded or loose - Cables and terminals must be tightened or cleaned |
Damaged belt or incorrectly adjusted belt tension - Install new belt or adjust belt tension as required |
Low battery capacity - Charge the battery |
Battery does not hold charge - Service or replace the battery |
Battery wiring harness failure - Inspect electrical cables for defects, repair or replace |
Loose or corroded battery terminals and cables - Tighten or service cables and terminals |
Low battery output voltage - Recharge the battery |
Drained or faulty battery - Replace or charge as required |
Starter motor failing - Starter should be replaced |
Incorrectly connected or disconnected wires - Check battery wires and connect correctly |
Transmission Troubleshooting |
Hard shifts |
Failure or improper clutch adjustment - Adjust or replace the clutch |
Gear shift linkage is damaged or loose - Service or replace shift linkage |
Bent or worn shift forks - Shift forks need to be changed |
Faulty gear shifting mechanism - Faulty parts must be changed |
Insufficient transmission oil pressure |
Low transmission oil level - Fill up the transmission oil |
Transmission fluid filter is plugged (if fitted) - Change or service the transmission fluid filter |
Damaged relief valve - Install a new relief valve |
Transmission makes excessive noise |
Bearings are worn or broken - Replace the bearings |
Low transmission oil level - Correct the transmission oil level |
Transmission fluid contamination - Change transmission fluid |
Incorrect backlash or gears are defective - Change worn gears or set backlash correctly |
Bent or worn shift forks - Shift forks need to be changed |
Broken gaskets or seals - Seals and gaskets need to be replaced |
Cracked transmission case - Install a new transmission case |
Hydraulics Troubleshooting |
Excessive hydraulic system heat |
Improper hydraulic system pressure setting - Set the pressure properly |
Main relief valve is faulty or misadjusted - Adjust or change relief valve |
Dirty hydraulic oil - The oil must be changed |
Air enters in hydraulic system - Check the pump seals, suction line, and fittings |
Low hydraulic oil pressure |
Hydraulic oil level is low - Add oil to the hydraulic system |
Hydraulic fluid filter element is dirty - Clean the hydraulic filter or install new filter element |
Hydraulic pump is defective - Test pump flow rate and replace pump if required |
Hydraulic control valve block is defective or set improper - Set correctly or replace |
Hydraulic cylinder malfunction - Check the hydraulic cylinder parts for damage or wear and replace if necessary |
Hydraulic pipes are leaking - Find leaks in the system and fix it |
3-point hitch does not raise or raises very slowly |
Hydraulic oil level is low - Fill the hydraulic system with oil |
Hydraulic fluid is too cold - Allow fluid to warm |
Hydraulic oil filter clogging - Change the hydraulic filter element or service if required |
Hydraulic pump failure - Check the pump capacity and replace pump if required |
Main relief valve is damaged or adjusted improperly - Replace or set up the relief valve |
Hydraulic control valve is faulty or out of adjustment - Replace or adjust properly |
Hydraulic cylinder is faulty - Inspect cylinder components for wear or damage and change if required |
Disconnected or damaged suction pipe - Connect or replace |
Three-point hitch dropping is too slow or cannot be dropped |
Defective or incorrect setting hydraulic control valve block - Adjust correctly or replace |
Hydraulic cylinder is faulty - Check cylinder parts for wear or damage and replace if necessary |
Worn hitch rock shaft - Install a new shaft |
Hitch has mechanical defects - Replace defective or worn hitch components |
Hitch lowering or lifting is not smoothly |
Hydraulic system sucks air - Inspect the suction line, pump seals, and fittings |
Hydraulic oil contamination - Change the oil |
Hydraulic pump malfunction - Flow-rate hydraulic pump and replace pump if necessary |
Faulty or incorrect setting hydraulic spool valve - Replace or adjust properly |
Broken hydraulic cylinder - Check the hydraulic cylinder parts for damage or wear and replace if necessary |
Steering System Troubleshooting |
Difficult steering |
Steering column is damaged or incorrectly assembled - Steering column must be assembled correctly or changed |
Air trapped in the steering system - Bleed the system of air |
Clogged steering filter - Install new steering filter element |
Improper toe-in - Adjust toe-in wheels properly |
Front tires are worn out - Install new tires |
Faulty steering pump - Steering pump needs to be repaired or replaced |
Power steering control valve is damaged or worn - Repair or change the steering control valve |
Relief valve seizing or malfunction - Flush relief valve or change if necessary |
Low steering fluid level - Fill the steering system with fluid |
Steering system has oil leaks - Tighten the steering line and hose joints |
Excessive steering wheel play |
Steering column coupling or shaft is worn - Change defective part |
Power steering control valve is worn or defective - Check and replace as required |
Faulty or worn steering unit - Replace or repair steering unit as required |
Steering pump is faulty - Install a new steering pump |
Steering tie-rod ends or linkage are worn - Replace damaged part |
Front wheels wander to left or right |
Incorrect tire pressure - Inflate the tires correctly |
Not adjusted toe-in - Adjust toe-in correctly |
Worn or faulty steering tie-rod ends or linkage - Replace failed part |
Faulty or worn power steering control valve - Replace or repair steering control valve as required |
Steering cylinder is worn - Replace or repair hydraulic steering cylinder |
Incorrectly adjusted or damaged front hub bearings - Replace or adjust the bearings correctly |
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Farm Tractors Technical Specifications |