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John Deere 2120 Troubleshooting
The
John Deere 2120 tractor was manufactured between 1969 and 1972. The JD 2120
powerline components: John Deere four stroke 4-cylinder direct injection
liquid-cooled diesel engine and 8x4 unsynchronized gear transmission, or
two-speed power shift transmission with 16 forward and 8 reverse gears.
A 219 cubic inches (3.6 L) engine has a cylinder bore of 4.02" (102 mm),
piston stroke of 4.33" (110 mm), rated power of 68 hp (50.7 kW), and
maximum torque of 69.6 Nm (51.3 lb-ft) at 1500 rev/min. Max. forward
speed - 18.6 mph (29.9 kph), max. reverse speed - 8.1 mph (13 kph).
The closed center hydraulic system used a piston pump with a flow rate
of 12.4 gal/min (46.9 liters per minute). The hydraulic pressure is 155
bar (2250 psi). The John Deere 2120 is equipped with a power assist
steering, differential hydraulic wet disc brakes, 7.50x16 front tires
and 15.5x38 rear tires. The wheelbase is 86 inches (2180 mm).
| Engine Troubleshooting |
| Engine won't start or hard to start |
| Clogged fuel filter element - Clean the filter or install new filter element |
| Fuel shut-off valve closed - Open the fuel shut-off valve |
| Water, dirt, or air in fuel system - Drain, flush, fill, and bleed system |
| Fuel injectors are damaged or dirty - Change fuel injectors |
| Fuel injection pump is defective - Repair or change injection pump |
| Engine has bad compression - Check cylinder block and replace defective parts |
| Engine stops during operation |
| Engine has not warmed up to the recommended temperature - Warm up engine as required |
| Air in fuel lines - Bleed fuel lines |
| Fuel injection failed - Use correct settings |
| Fuel filter clogging - Service the filter |
| Dirty or faulty injectors - Service or change fuel injectors |
| Engine starts but immediately shuts off |
| Unadjusted fuel injection pump timing - Check the fuel injection pump timing setting |
| Clogged fuel filter element - Change filter element |
| Dirty or defective injector nozzles - Change injector nozzles |
| Fuel injection pump is broken - Change or repair the pump |
| Air cleaner clogging - Replace or service air cleaner element |
| Incorrect low idle speed adjustment - Correct low idle settings |
| Defective fuel injection pump - Install a new fuel pump or repair |
| Dirty or defective injector nozzles - Install new set of properly balanced nozzles |
| Valve clearance is not correct - Adjust valve clearance |
| Lack of coolant in cooling system - Fill the radiator to the required level. If there are leaks in the system, replace worn components |
| Cooling system parts are damaged or system is dirty - Change faulty components or flush the cooling system |
| Insufficient engine oil - Check and refill engine oil |
| Damaged fan belt or incorrect belt tension - Adjust belt tension properly or replace it |
| Thermostat failure - Install new thermostat |
| Fuel injectors are clogged or faulty - Service or change fuel injectors |
| Improper fuel injection pressure - Adjust pressure to proper level |
| Air filter is clogged - Air filter maintenance required |
| Oil filter is clogged - Change or clean engine oil filter element |
| Engine is running overloaded - Load reducing required |
| Valve clearance is out of adjustment - Need to adjust valve clearance |
| Incorrectly adjusted low idle speed - Correct low idle settings |
| Fuel hoses or pipes are clogged - Fuel hoses and pipes must be clean |
| Engine low compression: Leaking or faulty valves - Have valves replaced |
| Engine knocking sound or abnormal noise |
| Incorrectly set fuel injection pump timing - Adjust the fuel injection pump timing correctly |
| Fuel injector nozzles are dirty or defective - Service or replace injector nozzles |
| Engine oil insufficient - Add oil to the engine crankcase |
| Low coolant temperature - Warm up to required temperature |
| Main bearings or crankshaft wear - Crankshaft or bearings need to be replaced |
| Piston rings are defective or broken - Piston rings replacement required |
| Loose flywheel screws - Check the flywheel screws and tighten as required |
| Engine consuming too much oil |
| Oil leaking: Worn seals or gaskets - Defective components must be replaced |
| Oil viscosity is wrong - Use correct viscosity oil |
| Piston rings are stuck or broken - Have piston rings replaced |
| Worn valve stems and valve guides - Need to replace the valves |
| Pistons or cylinder liners are scuffed - Check pistons and liners, change as required |
| Electrical System Troubleshooting |
| Battery will not charge |
| Battery is defective - Battery replacement required |
| Damaged battery wiring harness - Inspect wiring for damage, replace or repair |
| Loose or corroded battery terminals and cables - Tighten or clean terminals and cables |
| Belt damage or incorrect belt tension adjustment - Replace belt or adjust belt tension correctly |
| Starter motor cranks slow |
| Battery voltage is low - Battery needs to be recharged |
| Battery discharges quickly - Service charging system or replace battery |
| Bad battery electrical wire harness - Check wires for malfunctions, repair or replace |
| Loose or corroded battery terminals and cables - Clean or tighten terminals and cables |
| Battery voltage is low - Low battery charging, charge as required |
| Discharged or faulty battery - Charge or change the battery |
| Starter motor failure - Repair or replace starter |
| Disconnected or incorrectly connected cables - Need to reconnect cables correctly |
| Transmission Troubleshooting |
| Hard shifts |
| Failure or improper clutch adjustment - Adjust or change the clutch |
| Damaged or loose gear shift linkage - Replace or repair the shift linkage |
| Damaged or worn shift forks - Shift forks need to be replaced |
| Faulty parts in the gear shifting mechanism - Change faulty parts |
| Transmission fluid pressure is insufficient |
| Fluid level is low - Check and refill the transmission fluid |
| Transmission oil filter element is dirty (if fitted) - Replace or clean transmission oil filter |
| Relief valve sticking - Replace relief valve |
| Transmission is making noise |
| Broken or worn bearings - Replace faulty bearings |
| Not enough fluid in transmission - Fill the transmission housing with fluid |
| Contaminated transmission oil - Change transmission oil |
| Damaged gears or improper backlash - Set backlash correctly or change the gears |
| Bent or worn shift forks - Shift forks need to be replaced |
| Transmission fluid leakage |
| Gaskets or seals are damaged - Install new components |
| Cracked transmission case - Install a new transmission case |
| Hydraulics Troubleshooting |
| Excessive hydraulic system heat |
| System pressure has not been adjusted correctly - Pressure needs to be adjust correctly |
| Main relief valve incorrect adjustment or failure - Replace or set up the relief valve |
| Hydraulic oil is contaminated - Fill up with fresh hydraulic oil |
| Air enters in hydraulic system - Check the pump seals, suction pipe, and fittings |
| Hydraulic fluid pressure is insufficient |
| Lack of hydraulic oil - Fill up the hydraulic oil |
| Dirty hydraulic oil filter - Replace hydraulic filter element or service if necessary |
| Hydraulic pump not working - Check pump performance and change it if necessary |
| Hydraulic control valve is faulty or out of adjustment - Adjust properly or replace |
| Hydraulic cylinder is broken - Inspect cylinder components for damage or wear and change if required |
| Hydraulic lines are leaking - Inspect hydraulic system for leaks and repair it |
| Hitch cannot be lifted or lifting is too slow |
| Not enough hydraulic oil in the system - Check oil level and add hydraulic oil as required |
| Cold fluid in hydraulic system - Wait for fluid to warm up |
| Hydraulic fluid filter element clogging - Change the hydraulic filter element or service if required |
| Damaged hydraulic oil pump - Flow-rate pump and change pump if necessary |
| Main relief valve malfunction or incorrect adjustment - Adjust or change relief valve |
| Damaged or incorrect adjusted hydraulic control valve - Adjust properly or change |
| Hydraulic cylinder is broken - Check cylinder components for wear or damage and change if necessary |
| Broken or loose suction line - Retighten or change |
| 3-point hitch fails to drop or drops slowly |
| Faulty or incorrect setting hydraulic spool valve - Adjust correctly or change |
| Hydraulic cylinder is not working - Inspect cylinder components for wear or damage and change if required |
| Hitch cross shaft is worn - Install a new shaft |
| Mechanical parts of the hitch are damaged - Change defective or worn hitch parts |
| Hitch jerks when drop or lift |
| Air in hydraulic system - Inspect the pump seals, suction pipe, and fittings |
| Dirty hydraulic oil - The oil must be changed |
| Damaged hydraulic oil pump - Test pump flow rate and replace pump if required |
| Hydraulic control valve block is not set properly or defective - Adjust correctly or change |
| Hydraulic cylinder malfunction - Check the hydraulic cylinder parts for damage or wear and replace if necessary |
| Steering System Troubleshooting |
| Steering wheel is difficult to turn |
| Steering column is defective or improperly assembled - Change steering column or assemble properly |
| Aeration in steering system - Bleed air |
| Toe-in adjustment is incorrect - Check and adjust toe-in |
| Front tires are worn out - Install new tires |
| Steering pump is faulty - Repair or replace steering pump |
| Damaged or worn power steering valve - Inspect and change as required |
| Faulty steering box parts - Replace defective components of power steering box |
| Low steering oil level - Fill up the steering oil |
| Oil leaks in the steering system - Retighten steering hose and pipe connections |
| Excessive steering wheel play |
| Worn steering column shaft or coupling - Replace faulty component |
| Defective or worn power steering valve - Replace or repair steering valve as required |
| Faulty steering box components - Replace defective components of power steering box |
| Steering pump malfunction - Steering pump needs to be replaced or repaired |
| Steering linkage or tie-rod ends are defective - Change damaged component |
| Tractor pulls to right or left |
| Tires are not properly inflated - Inflate tires as required |
| Toe-in adjustment is incorrect - Adjust toe-in wheels properly |
| Faulty or worn steering tie-rod ends or linkage - Change failed part |
| Worn steering box parts - Replace defective parts of power steering box |
| Damaged or worn power steering valve - Repair or replace the steering valve |
| Incorrectly adjusted or worn front hub bearings - Adjust correctly or replace bearings |
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| Farm Tractors Technical Specifications |
