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Kubota B7500 Troubleshooting

The Kubota B7500 is a four-wheel drive compact utility tractor. This model was manufactured from 2000 to 2003. The tractor was designed in two versions: B7500D (gear drive) and B7500HSD (hydrostatic drive).

The Kubota B7500 is powered by Kubota D1005-E three-cylinder liquid cooled diesel engine. A 61.1 cubic inches (1 L) engine has a cylinder bore of 3" (76 mm), piston stroke of 2.9" (73.6 mm), and rated power of 19 hp (14.1 kW).

The Kubota B7500 fitted with two transmission options: mechanical transmission with 6 forward and 2 reverse gears, or 2-range hydrostatic transmission with infinite forward and reverse gears. The maximum travel speed (forward and reverse): 12.7 mph (20.4 km/h) / 7.3 mph (11.7 km/h). The open center hydraulic system includes a dual gear pump with fluid flow rate of 7 gal/min (26.5 l/min). The tractor is equipped with 6.00x12 front tyres and 9.50x16 rear tyres. The wheelbase is 59" (1490 mm).

The Kubota B7500 is compatible with the following attachments: 54", 60" mid-mount 3-blade side discharge rotary mower decks with cutting height of 1.5-4.0 in (30-100 mm) and hydraulic lift system, and Kubota LA302 loader with lift capacity to max height of 770 lbs (350 kg).

Engine Troubleshooting
Engine hard starting or not starting
Fuel filter plugging - Replace filter element
Closed fuel supply valve - Open supply valve to inject fuel
Fuel-line is leaking air - Retighten clamps, replace defective pipes
Fuel injectors are clogged or faulty - Check fuel injectors and replace if required
Fuel injection pump is damaged - Rebuild or replace pump
Bad compression - Inspect cylinder block and change worn parts
Engine shuts off unexpectedly while running
Engine is cold - Warm up engine as required
Fuel-line is leaking air - Retighten clamps, replace defective pipes
Bad fuel injection - Check and adjust
Plugged fuel filter - Change filter element
Faulty or dirty injectors - Test fuel injectors and change if necessary
Diesel starts but then shuts off
Unadjusted fuel injection pump timing - Check the fuel injection pump timing setting
Fuel filter is clogged - Install new filter element
Faulty fuel injector nozzles - Inspect injector nozzles and change if required
Faulty fuel injection pump - Install a new pump or rebuild
Clogged air cleaner - Clean or replace the air cleaner element
Engine stalling at idle
Wrong adjustment of low idle speed - Adjust as required
Fuel injection pump malfunction - Replace injection pump or repair it
Fuel injector nozzles are damaged or dirty - Service or replace nozzles if required
Improper valve clearance - Check and adjust
Engine is overheated
Coolant level is low - Coolant needs to be refilled. Repair any leaks if necessary
Cooling system components are worn or system is clogged - Replace faulty parts or service cooling system
Engine oil level is insufficient - Fill up the engine oil
Incorrect fan belt tension or broken belt - Change or adjust belt tension correctly
Defective thermostat - Install new thermostat
Diesel engine is losing power
Faulty or dirty injectors - Test fuel injectors and change if necessary
Uneven fuel injection pressure - Adjust to correct pressure
Clogged air filter - Install new filter element or replace it
Oil filter is dirty - Service or replace engine oil filter
Engine is overloaded - Reduce the load or operate the tractor in lower gears
Valve clearance is wrong - Correct valve clearance needs to be set
Incorrectly adjusted low idle speed - Adjust as required
Fuel hoses or pipes clogging - Clean fuel system pipes and hoses
Engine lost compression: Inlet or outlet valves are defective - Have valves replaced
Engine noise or knocking
Fuel injection pump out of timing - Correct injection timing
Clogged or defective injector nozzles - Install a new set of well-balanced nozzles
Low engine oil level - Fill the crankcase with engine oil
Engine has not warmed up to the recommended temperature - Warm up the engine as required
Worn main bearings or crankshaft - Install new parts
Defective or broken piston rings - Replace piston rings
Flywheel mounting screws are loose - Tighten the screws
Excessive engine oil consumption
Oil leaks: Seals or gaskets are defective - Defective components must be replaced
Oil viscosity is incorrect - Use correct viscosity oil
Piston rings are stuck or worn - Piston rings need to be replaced
Worn valve stems and valve guides - Replace the valves
Pistons or cylinder liners are damaged - Inspect pistons and liners, change as required

Electrical System Troubleshooting
Battery is not charging
Worn-out battery - Battery change required
Bad battery cable harness - Inspect cables for malfunctions, repair or change
Loose or corroded terminals and cables - Tighten or clean cables and terminals
Defective belt or improperly adjusted belt tension - Replace belt or properly adjust belt tension
Starter cranks slow
Low battery voltage - Battery is drained, recharge it
Battery discharges quickly - Service charging system or replace battery
Battery wiring harness damage - Inspect battery wiring for damage, replace or repair
Battery terminals and cables are loose or corroded - Terminals and cables need to be tightened or cleaned
Starter motor is not working
Low battery output voltage - Battery needs to be recharged
Drained or defective battery - Replace or charge as required
Starter motor is faulty - Replace or repair starter
Disconnected or incorrectly connected cables - Need to reconnect cables correctly

Transmission Troubleshooting
Gear hard to shift
Clutch is unadjusted or worn - Change or adjust clutch
Gear shift linkage is stuck or damaged - Repair or change shift linkage
Shift forks are worn or damaged - Shift forks need to be changed
Gearshift mechanism is worn out - Repair or replace worn components if required
Insufficient transmission fluid pressure
Low transmission fluid level - Fill the transmission housing with fluid
Transmission oil filter element is dirty (if fitted) - Change or service the transmission oil filter
Relief valve is defective - Replace relief valve as required
Transmission is excessively noisy
Damaged or worn bearings - Bearings need to be replaced
Not enough oil in transmission - Checking transmission oil level and add if necessary
Dirty transmission fluid - Transmission fluid must be changed
Backlash is incorrect or gears are worn - Replace gears or adjust backlash properly
Shift forks are worn or damaged - Install new shift forks
Transmission fluid leakage
Worn gaskets or seals - Seals and gaskets need to be replaced
Cracked transmission housing - Housing needs to be replaced

Hydrostatic Transmission Troubleshooting
Hydrostatic transmission noises
Transmission fluid level is insufficient or fluid is contaminated - Change transmission fluid or fill to required level
Defective or out of adjustment speed control rod linkage - Adjust or repair rod linkage
Relief valve failure - Replace the valve
Transmission is under excessive load - Reduce transmission load
Transmission parts are worm or defective - Change or repair damaged parts
Transmission oil overheating
Lack of transmission fluid supply - Fill system with correct transmission fluid level
Transmission fluid filter is plugged - Change or service the transmission fluid filter
Cooling components are damaged or clogged - Check all cooling components and repair or change if required
Excessive transmission load - Reduce the load is required
Loss of power
Not enough oil in transmission - Check transmission oil level and add oil as required
Charge pressure is too low - Test charge pressure
Relief valve is worn or damaged - Change relief valve
Transmission fluid leaking
Gaskets or seals are broken - Replace worn gaskets or seal
Internal transmission case pressure is too high - Replace defective components
Plugged transmission fluid drain pipe - Service or change drain pipe

Hydraulics Troubleshooting
Hydraulic system is overheated
Improper pressure in hydraulic system - Adjust properly
Main relief valve is damaged or adjusted improperly - Adjust or replace the relief valve
Hydraulic fluid is contaminated - Fill up with new hydraulic fluid
Hydraulic system sucks air - Inspect the pump seals, suction pipe, and fittings
Insufficient hydraulic oil pressure
Hydraulic oil level is insufficient - Fill the hydraulic system with oil
Hydraulic oil filter element clogging - Clean or change hydraulic filter
Defective hydraulic pump - Check the pump performance and replace it if required
Hydraulic spool valve block is faulty or out of adjustment - Adjust correctly or change
Defective hydraulic cylinder - Check the hydraulic cylinder parts for damage or wear and replace if necessary
Hydraulic piping leaks - Detect leaks in the system and fix it
Hitch won't lift or lifts slowly
Hydraulic oil level is insufficient - Fill the hydraulic system with oil
Cold fluid in hydraulic system - Wait for fluid to warm up
Hydraulic fluid filter clogging - Clean or replace the hydraulic filter
Damaged hydraulic oil pump - Check the pump performance and replace it if required
Main relief valve malfunction or incorrect adjustment - Adjust or change relief valve
Defective or not adjusted hydraulic control valve - Set properly or replace
Hydraulic cylinder is broken - Check cylinder components for damage or wear and change if necessary
Damaged or disconnected suction pipe - Connect or replace
Hitch won't lower or lowers slowly
Hydraulic control valve block is not set properly or defective - Set properly or replace
Defective hydraulic cylinder - Check cylinder parts for wear or damage and replace if necessary
Worn lift arm shaft - Change the shaft
Mechanical parts of the hitch are damaged - Replace worn or faulty hitch components
Hitch is lowered or raised jerkily
Hydraulic system sucks air - Inspect the pump seals, suction line, and fittings
Hydraulic fluid is contaminated - Fill up with new hydraulic fluid
Hydraulic pump not working - Check the pump capacity and replace pump if required
Defective or not adjusted hydraulic spool valve - Replace or adjust correctly
Hydraulic cylinder malfunction - Inspect the hydraulic cylinder parts for damage or wear and replace if required

Steering System Troubleshooting
Steering wheel turns hard
Steering column is broken or improperly installed - Steering column must be installed properly or replaced
Air trapped in the steering system - Bleed air
Improper toe-in - Adjust toe-in wheels properly
Tires are incorrectly inflated - Inflate as required
Steering pump is faulty - Replace or repair steering pump
Worn or defective power steering valve - Replace or repair steering valve as required
Faulty steering box components - Change defective steering box parts
Steering fluid insufficient - Check and refill steering fluid
Steering system has oil leaks - Retighten steering line and hose connections
Steering wheel free play is excessive
Steering column coupling or shaft is worn - Replace defective part
Power steering valve is defective or worn - Inspect and replace as required
Faulty steering box parts - Change defective steering box parts
Steering pump stopped working - Repair or replace steering pump
Faulty or worn steering linkage or tie-rod ends - Replace failed component
Tractor pulls to right or left
Front tires are worn out - Install new tires
Incorrect toe-in - Check and adjust toe-in
Worn or faulty steering tie-rod ends or linkage - Replace damaged part
Faulty steering box components - Replace defective parts of power steering box
Power steering valve is damaged or worn - Repair or change the steering valve
Front hub bearings are damaged or incorrectly adjusted - Install new bearings or adjust it correctly



Farm Tractors Technical Specifications
JD 1026R JD 3650 JD 6400 JD 7810
FORD 1320 FORD 2810 FORD 3930 FORD 5600
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