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Kubota L4701 Troubleshooting
The
Kubota L4701 compact utility tractor was manufactured from 2014 to 2021. This
model was designed in 2 versions: L4701F (2WD) and L4701DT (4WD). The Kubota
L4701 driveline consists of a 148.5 cu.in (2.43 L) Kubota V2403-CR-E4 4-cycle
vertical 4-cylinder direct injection water-cooled diesel engine with a rated
power of 47.3 Hp (35.2 kW), and Synchro-Shuttle transmission with 8 forward and
8 reverse gears.
Max forward speed - 14.9 mph (24.1 km/h), maximum reverse speed - 14.3
mph (23.1 km/h). The open center hydraulic system includes a gear pump
with fluid flow rate of 7.8 gallons per minute (29.5 liters per minute).
The hydraulic pressure is 177 bar (2560 psi). The 2-wheel drive models
are equipped with 7.5Lx15 front tires and 14.9x24 rear tires. The 8.3x16
front tires and 14.9x24 rear tires are used for tractors with 4-wheel
drive.
The wheel base is 72.8" (1850 mm) for 4x2 (2WD) models and 72.6" (1845
mm) for 4x4 (4WD) models. Compatible attachments for the tractor:
Kubota
LA765 front-end loader with a maximum lift height of 105.2" (2670 mm),
and Kubota BH92 backhoe with 2-ft flat digging depth of 106.1" (2690
mm).
Engine Troubleshooting |
Engine won't start or hard to start |
Fuel filter is clogged - Clean or change the filter |
The fuel shut-off valve is closed - Open fuel shut-off valve |
Air in fuel system - Air-bleed fuel system |
Faulty or dirty injectors - Clean or replace fuel injectors |
Fuel injection pump malfunction - Change pump or rebuild it |
Bad engine compression - Check cylinder block and replace worn parts |
Engine stalls while running |
Engine is not fully warmed up - Warm up to required temperature |
Water, dirt, or air in fuel system - Drain, flush, fill, and bleed system |
Uneven fuel injections - Repair or adjustment |
Clogged fuel filter element - Replace the filter element |
Fuel injectors are damaged or dirty - Test fuel injectors and change if necessary |
Timing of fuel injection pump is not adjusted - Fuel injection pump timing adjustment needs to be corrected |
Clogged fuel filter element - Change filter element |
Dirty or defective injector nozzles - Service or replace nozzles if required |
Fuel injection pump malfunction - Replace or rebuild injection pump |
Dirty air cleaner element - Install new cleaner element or replace it |
Low idle speed setting is incorrect - Adjust as required |
Faulty fuel injection pump - Install a new pump or rebuild |
Fuel injector nozzles are faulty - Change injector nozzles |
Excessive valve clearance - Check and adjust |
Lack of coolant in cooling system - Fill radiator to proper level. Check system for leaks |
Cooling system parts are defective or system is clogged - Change faulty components or flush the cooling system |
Insufficient engine oil - Check and refill engine oil |
Worn fan belt or improper belt tension - Adjust belt tension correctly or change it |
Thermostat malfunction - Check and replace if required |
Clogged or damaged injectors - Clean or replace fuel injectors |
Insufficient fuel injection pressure - Adjust to correct pressure |
Air filter is clogged - Service or change air filter |
Clogged oil filter - Replace or service engine oil filter |
Engine overload - Reduce engine load |
Valve out of adjustment - Have it adjusted |
Incorrectly set low idle speed - Correct low idle adjustment |
Fuel pipes or hoses clogging - Clean fuel hoses and pipes |
Insufficient engine compression: Valves are faulty or leaking - Replace the valves |
Abnormal engine noise or knocking |
Incorrect setting of fuel injection pump timing - Check and correct adjustments |
Dirty or defective injector nozzles - Test injector nozzles and replace as required |
Engine oil level is low - Fill up the oil to required level |
Coolant temperature is low - Warm up engine as required |
Crankshaft or main bearings wear - Change defective components as required |
Stuck or worn piston rings - Have piston rings replaced |
Loose flywheel screws - Inspect the flywheel screws and tighten securely |
Engine using too much oil |
Oil leaking: Damaged gaskets or seals - Replace worn parts to avoid leaks |
Improper oil viscosity - Fill up with the proper oil viscosity |
Damaged or seized piston rings - Have piston rings replaced |
Valve stems and guides are worn - Valves need to be changed |
Damaged cylinder liners or pistons - Inspect liners and pistons, replace as necessary |
Electrical System Troubleshooting |
Battery won’t charge |
Battery is defective - Use a new battery |
Battery wiring harness damage - Inspect battery wiring for damage, replace or repair |
Loose or corroded cables and terminals - Service or tighten battery terminals and cables |
Improper belt tension adjustment or damaged belt - Adjust belt tension properly or change belt |
Low battery output - Charge the battery |
Battery discharges quickly - Service or change the battery |
Battery electrical wire harness failure - Inspect wires for defects, change or repair |
Loose or corroded terminals and cables - Tighten or clean terminals and cables |
Battery voltage is low - Battery is drained, recharge it |
Discharged or worn battery - Charge or change the battery |
Starter motor failure - Starter should be changed |
Improperly connected or disconnected cables - Check battery cables and connect properly |
Transmission Troubleshooting |
Gears are hard to shift |
Misadjusted or defective clutch - Adjust correctly or replace |
Gear shift linkage is loose or broken - Replace or repair the shift linkage |
Worn or damaged shift forks - Replace defective shift forks |
Defective gearshift mechanism - Replace defective components |
Insufficient transmission fluid pressure |
Insufficient oil supply - Fill up the transmission oil |
Clogged transmission oil filter (if equipped) - Change or clean the transmission oil filter |
Relief valve is defective - Install a new relief valve |
Transmission is making noise |
Cracked or worn bearings - Faulty bearings should be changed |
Low transmission fluid level - Fill the transmission housing with fluid |
Contaminated transmission fluid - Fill up with fresh transmission fluid |
Improper backlash or damaged gears - Replace gears or adjust backlash properly |
Shift forks are worn or damaged - Install new shift forks |
Transmission fluid leaking |
Gaskets or seals are defective Gaskets or seal replacement required |
Cracked transmission housing - Housing needs to be replaced |
Hydraulics Troubleshooting |
Hydraulic system is too hot |
Incorrect pressure in hydraulic system - Changing the system pressure |
Main relief valve malfunction or incorrect adjustment - Adjust relief valve or change if required |
Contaminated hydraulic oil - Change hydraulic oil |
Hydraulic system sucks air - Inspect the pump seals, suction pipe, and fittings |
Low hydraulic oil pressure |
Hydraulic fluid level is low - Check and refill the hydraulic fluid |
Hydraulic fluid filter element is dirty - Replace hydraulic filter element or service if necessary |
Hydraulic pump failure - Check the pump performance and replace it if required |
Damaged or incorrect adjusted hydraulic control valve - Set correctly or replace |
Hydraulic cylinder malfunction - Check cylinder components for damage or wear and change if necessary |
Leakage in hydraulic lines - Identify leaks in the system and repair it |
Hitch fails to lift or lifts slowly |
Lack of hydraulic fluid - Need to add fluid |
Hydraulic fluid is too cold - Allow fluid to warm |
Hydraulic oil filter element clogging - Clean the hydraulic filter element or replace if necessary |
Defective hydraulic pump - Check pump flow and change pump if necessary |
Unadjusted or defective main relief valve - Adjust relief valve or change if required |
Hydraulic control valve block is not set properly or defective - Change or adjust correctly |
Faulty hydraulic cylinder - Check cylinder components for wear or damage and change if necessary |
Damaged or disconnected hydraulic suction pipe - Connect or replace the pipe |
3-point hitch fails to drop or drops slowly |
Damaged or incorrect adjusted hydraulic control valve - Replace or set properly |
Hydraulic cylinder is not working - Check cylinder components for damage or wear and change if necessary |
Hitch rock shaft is worn Replace the shaft |
Damaged mechanical components of the hitch - Replace worn or faulty hitch components |
Hitch lowering or lifting is not smoothly |
Air leaks in hydraulic system - Inspect the pump seals, suction pipe, and fittings |
Dirty hydraulic oil - The oil must be changed |
Damaged hydraulic oil pump - Check the pump performance and replace it if required |
Hydraulic spool valve block is defective or set improper - Adjust properly or change |
Hydraulic cylinder is faulty - Check cylinder components for wear or damage and change if necessary |
Steering System Troubleshooting |
Steering is stiff |
Steering column is damaged or improperly mounted - Replace the steering column or mount it properly |
Aeration in steering system - Bleed air |
Not adjusted toe-in - Check and adjust toe-in |
Tire pressure is not correct - Check tire pressure and inflate as required |
Faulty steering pump - Check the hydraulic steering pump and change if necessary |
Damaged or worn hydrostatic steering unit - Inspect and replace as required |
Relief valve malfunction or sticking - Check relief valve and change if required |
Lack of steering oil - Fill the steering system with oil |
Oil leaks in the steering system - Tighten connections of hydraulic hoses and pipes in steering system |
Excessive play in steering |
Steering column coupling or shaft is extremely worn out - Replace faulty part |
Worn or damaged hydrostatic steering unit - Inspect and change as required |
Hydraulic steering pump is defective - Repair or replace steering pump |
Faulty or worn steering linkage or tie-rod ends - Change failed part |
Tractor is pulling to left or right |
Front tires are worn out - Install new tires |
Toe-in adjustment is incorrect - Adjust toe-in correctly |
Steering tie-rod ends or linkage are defective - Change failed part |
Hydrostatic steering unit is damaged or worn - Change or repair steering unit if required |
Damaged steering cylinder - Repair or change hydraulic steering cylinder |
Front hub bearings are incorrectly adjusted or worn - Replace the bearings or adjust it properly |
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Farm Tractors Technical Specifications |