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Kubota L3750 Troubleshooting

The Kubota L3750 L-series compact utility tractor was manufactured from 1984 to 1990. The tractor was designed in 2 versions: L3750F (2WD) and L3750DT (4WD).

The Kubota L3750 powerline system components: Kubota F2302-DI 5-cylinder direct injection water-cooled naturally aspirated diesel engine and partially synchronized transmission with 8 forward and 8 reverse gears. A 141.9 cubic inches (2.3L) engine has a cylinder bore of 3.35" (85 mm), piston stroke of 3.23" (82 mm), and rated power of 45 hp (33.6 kW).

The maximum travel speed (forward/reverse): 14.2 mph (22.8 km/h). The open center hydraulic system used a gear pump with rated capacity of 8.7 gal/min(32.9 l/min). The hydraulic system pressure is 172.5 bar (2500 psi). The 2-wheel drive models are equipped with 6.50x16 front tyres and 13.6x28 rear tyres. The 9.50x16 front tyres and 13.6x28 rear tyres fit 4-wheel drive tractors. The wheelbase is 76.4" (1940 mm).

Compatible attachments for the Kubota L3750 tractor: Kubota BF900 loader with lift capacity to full height of 1985 lbs (900 kg), and Kubota L4540 backhoe with maximum digging depth of 123" (3120 mm) and bucket digging force of 3980 lbs (1805 kg).

Engine Troubleshooting
Diesel won't start or hard to start
Fuel filter is clogged - Service or replace the filter
Fuel is not supplied from the tank to the system - Check the fuel shut-off valve
Fuel-line is leaking air - Retighten clamps, replace defective pipes
Fuel injectors are damaged or dirty - Change fuel injectors
Fuel injection pump malfunction - Repair or install a new fuel pump
Low engine compression - Check and replace worn parts
Engine stalls during operation
Engine is not fully warmed up - Warm up the engine as required
Air in fuel pipes - Bleed fuel pipes
Irregular fuel injection - Adjust fuel injection timing
Dirty fuel filter element - Service or replace the filter
Fuel injectors are defective or dirty - Service or change fuel injectors
Diesel engine stalls after starting
Fuel injection pump timing is incorrect - Correct injection timing
Fuel filter clogging - Clean the filter element
Clogged or damaged injector nozzles - Service or replace injector nozzles
Faulty fuel injection pump - Replace or repair injection pump
Dirty air cleaner - Replace or service air cleaner element
Engine shuts off while idling
Low idle speed setting is not correct - Adjust low idle speed
Fuel injection pump malfunction - Change or repair the pump
Fuel injector nozzles are damaged or dirty - Service or replace injector nozzles
Excessive valve clearance - Correct valve clearance needs to be set
Engine overheated
Low engine coolant - Top up coolant fluid. Check and repair damage to the cooling system if required
Cooling system is dirty or cooling components are failed - Replace faulty parts or flush the cooling system
Engine oil level low - Fill up the engine oil
Fan belt is defective or belt tension is not adjusted - Adjust belt tension properly or change it
Thermostat failure - Check and replace if required
Reduced engine power
Fuel injectors are defective or dirty - Inspect fuel injectors and replace if necessary
Fuel injection pressure is incorrect - Test fuel injection pressure and adjust it correctly
Air filter element is clogged - Install new filter element or replace it
Dirty oil filter - Clean or replace engine oil filter element
Engine is under excessive load - Load reducing is recommended
Incorrect valve clearance - Adjust to proper valve clearance
Low idle speed setting is incorrect - Adjust low idle speed
Clogged fuel pipes or hoses - Fuel hoses and pipes must be clean
Insufficient engine compression: Leaking or faulty valves - Replace the valves
Engine knocks or noises
Incorrectly set fuel injection pump timing - Fuel injection pump timing adjustment needs to be corrected
Dirty or defective injector nozzles - Inspect injector nozzles and change if required
Insufficient engine oil - Fill up the engine oil
Engine not warmed up - Normalize the temperature by warming up the engine
Main bearings or crankshaft are worn out - Replace crankshaft or bearings
Piston rings are damaged or broken - Piston rings replacement required
Flywheel screws are loose - Tighten the screws firmly
Diesel engine using too much oil
External oil leaks: Gaskets or seals may be damaged - Defective components must be replaced
Wrong oil viscosity - Fill up with the proper oil viscosity
Worn or stuck piston rings - Install new piston rings
Worn valve stems and valve guides - Valves replacement required
Scored pistons or cylinder liners - Inspect pistons and liners, replace as required

Electrical System Troubleshooting
Battery will not charge
Faulty cell in battery - Battery replacement required
Battery cable harness damage - Check battery cables for damage, change or repair
Loose or corroded battery cables and terminals - Tighten or clean terminals and cables
Belt damage or incorrect belt tension adjustment - Replace belt or correctly adjust belt tension
Starter turning slow
Low battery power - Battery is drained, recharge it
Battery discharges quickly - Battery needs service or replacement
Bad battery wiring harness - Inspect wiring for malfunctions, replace or repair
Loose or corroded battery cables and terminals - Clean or tighten terminals and cables
Starter will not work
Low battery capacity - Battery is drained, charge it
Drained or defective battery - Change or recharge battery
Starter motor failing - Starter should be changed
Wiring is improperly connected or disconnected - Need to reconnect the wiring properly

Transmission Troubleshooting
Difficult to shift gears
Worn or misadjusted clutch - Adjust clutch or change if necessary
Damaged or loose gear shift linkage - Service or replace shift linkage
Shift forks are worn or damaged - Install new shift forks
Worn gear shift mechanism - Replace worn components
Insufficient transmission oil pressure
Low transmission oil level - Correct the transmission oil level
Transmission fluid filter is dirty (if equipped) - Change or service the transmission fluid filter
Damaged relief valve - Replace valve as required
Transmission is making noise
Cracked or worn bearings - Replace the bearings
Not enough fluid in transmission - Fill up the transmission fluid
Dirty transmission oil - Transmission oil must be changed
Backlash is incorrect or gears are worn - Set backlash correctly or change the gears
Shift forks are worn or damaged - Shift forks need to be changed
External fluid leaks
Gaskets or seals are defective Gaskets or seal replacement required
Cracked transmission housing - Housing needs to be replaced

Hydraulics Troubleshooting
Hydraulic system overheated
The system pressure has not been corrected - Make the correct settings
Main relief valve failure or incorrect setting - Adjust the valve or replace if necessary
Hydraulic fluid contamination - Change hydraulic fluid
Air leaks in hydraulic system - Inspect the pump seals, suction line, and fittings
Low hydraulic system pressure
Not enough hydraulic oil in the system - Fill the hydraulic system with oil
Hydraulic oil filter element clogging - Service the hydraulic filter or change if required
Defective hydraulic pump - Flow-rate pump and change pump if necessary
Faulty or incorrect setting hydraulic spool valve - Change or set correctly
Faulty hydraulic cylinder - Check the hydraulic cylinder parts for damage or wear and replace if necessary
Hydraulic lines are leaking - Inspect hydraulic system for leaks and repair it
3-point hitch does not raise or raises very slowly
Hydraulic fluid level is insufficient - Check and refill the hydraulic fluid
Cold hydraulic oil - Warm up the oil
Hydraulic fluid filter clogging - Install a new hydraulic filter element
Hydraulic pump is defective - Test the pump flow rate and change pump if required
Main relief valve incorrect adjustment or failure - Adjust relief valve or change if required
Defective or not adjusted hydraulic control valve - Adjust correctly or change
Hydraulic cylinder is broken - Check cylinder components for damage or wear and change if necessary
Loose or damaged suction line - Tighten or replace
Hitch won't lower or lowers slowly
Hydraulic spool valve block is faulty or out of adjustment - Set correctly or replace
Defective hydraulic cylinder - Inspect cylinder parts for wear or damage and replace if required
Hitch rock shaft is worn Replace the shaft
Mechanical parts of the hitch are damaged - Change defective or worn hitch components
Hitch lower or lift is jerky
Air enters in hydraulic system - Check the pump seals, suction pipe, and fittings
Hydraulic fluid is contaminated - Fill up with new hydraulic fluid
Hydraulic pump failure - Test the pump flow rate and change pump if required
Defective or not adjusted hydraulic spool valve - Adjust correctly or replace
Hydraulic cylinder is faulty - Inspect cylinder parts for wear or damage and replace if required

Steering System Troubleshooting
Steering wheel turns hard
Worn or improperly mounted steering column - Mount the steering column properly or change it
Air trapped in the steering system - Air-bleed steering system
Toe-in adjustment is incorrect - Adjust toe-in properly
Front tires are worn out - Install new tires
Faulty steering pump - Check the steering pump and replace if necessary
Worn or defective power steering valve assembly - Replace or repair steering valve as required
Worn steering box components - Repair power steering box
Low steering oil level - Fill up the steering oil
Steering system oil leakage - Tighten the steering hose and line joints
Excessive steering wheel play
Steering column shaft or coupling is worn out - Replace faulty component
Power steering valve assembly is worn or defective - Inspect and change as required
Faulty steering box parts - Defective power steering box components must be replaced
Steering pump is faulty - Replace or repair steering pump
Faulty or worn steering tie-rod ends or linkage - Replace failed component
Tractor pulls to left or right
Tires are not properly inflated - Inflate tires as required
Toe-in adjustment is incorrect - Adjust toe-in correctly
Steering linkage or tie-rod ends are worn - Replace failed component
Damaged steering box parts - Defective power steering box components must be replaced
Damaged or worn power steering valve assembly - Inspect and change as required
Incorrectly adjusted or damaged front hub bearings - Install new bearings or adjust it correctly



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MF 250 MF 690 MF 3060 MF 6180
NH TC48DA NH M100 NH T7550 NH 8560
CASE IH 495 CASE IH 1255XL CASE IH 2140 CASE IH 2294