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Kubota M126X Troubleshooting

The Kubota M126X is a 4-wheel drive row crop tractor. This model was manufactured between 2009 and 2014. The Kubota M126X tractor is powered by 373.7 cu.in (6.1 L) Kubota V6108-TI-CRS 4-cylinder direct injection turbocharged intercooled diesel engine with a rated output power of 126 hp (94 kW).

The Kubota M126X is fitted with two types of transmission. 1st type: Intelli-Shift partial powershift transmission with 16 forward and 16 reverse gears. 2nd type: Intelli-Shift Creeper transmission with 24 forward and 24 reverse gears. The maximum travel speed - 22.5 mph (36.3 km/h), maximum creeper speed - 0.7 mph (1.1 km/h). The open center hydraulic system used a gear pump with rated fluid flow of 20.4 gpm (77.7 lpm). The hydraulic system pressure is 196 bar (2845 psi).

The tractor is equipped with a hydrostatic power steering, hydraulic wet disc brakes, 14.9R24 or 420/70R24 front tires, and 18.4R38 or 520/80R38 rear tires. The wheelbase is 105.9" (2680 mm). The Kubota M126X is compatible with Kubota LA2253 loader with a 84" (2130 mm) bucket and lift capacity to full height of 4877 lbs (2212 kg).

Engine Troubleshooting
Engine won't start or difficult to start
Fuel filter is clogged - Change filter element
No fuel injection - Open fuel cock to inject fuel
There is air in the fuel system - Bleed the system
Fuel injectors are damaged or dirty - Check fuel injectors and replace if required
Fuel injection pump damage - Repair or install a new fuel pump
Bad compression - Inspect cylinder block and change damaged parts
Engine stalls during operation
Coolant temperature is low - Warm up the engine as required
Air in fuel pipes - Bleed fuel pipes
Improper fuel injection - Fuel injection settings required
Fuel filter is dirty - Clean the filter element
Clogged fuel injectors - Clean or replace fuel injectors
Engine starts and immediately stops
Unadjusted fuel injection pump timing - Fuel injection pump timing adjustment needs to be corrected
Fuel filter is clogged - Service or replace the filter
Fuel injector nozzles fault - Service or replace injector nozzles
Fuel injection pump is damaged - Repair or install new pump
Air cleaner element is dirty - Replace cleaner or install new cleaner element
Engine stalls when idle
Low idle speed setting is not correct - Correct low idle adjustment
Faulty fuel injection pump - Repair or change injection pump
Clogged or damaged injector nozzles - Install a new set of well-balanced nozzles
Valve clearance is out of adjustment - Adjust valve clearance according to specifications
Engine overheats
Insufficient coolant - Refill to the correct level. Check radiator and hoses for leaks
Cooling system is dirty or cooling components are failed - Change faulty components or flush the cooling system
Engine oil level low - Fill up the engine oil
Improper fan belt tension or damaged belt - Adjust belt tension correctly or replace it
Defective or wrong type of thermostat - Check and replace if required
Engine power loss
Fuel injectors are defective or dirty - Inspect fuel injectors and replace if necessary
Fuel injection pressure is wrong - Repair or replace injection pump
Dirty air filter - Change or service air filter element
Engine oil filter is plugged - Clean or replace engine oil filter element
Engine is overloaded - Change to lower gear or reduce load
Valve out of adjustment - Check and adjust
Wrong adjustment of low idle speed - Normalize low idle speed
Fuel hoses or pipes clogging - Fuel pipes and hoses need to be cleaned
Engine compression too low: Intake or exhaust valves are damaged - Have valves replaced
Engine knocking or noise
Fuel injection pump out of timing - Fuel injection pump timing adjustment needs to be corrected
Fuel injector nozzles are defective or dirty - Replace fuel injector nozzles
Insufficient engine oil - Fill up the oil to required level
Engine is not fully warmed up - Warm up engine as required
Crankshaft or main bearings failure - Crankshaft or bearings need to be replaced
Piston rings are worn or broken - Piston rings replacement required
Flywheel bolts are loose - Bolts need to be tightened
Engine using too much oil
External oil leaks: Gaskets or seals may be damaged - Replace defective parts
Oil viscosity is incorrect - Fill up with the proper oil viscosity
Seized or wear piston rings - Replace piston rings
Damaged valve stems or valve guides - Valves need to be changed
Worn cylinder liners or pistons - Inspect liners and pistons, fit new parts as necessary

Electrical System Troubleshooting
Battery will not charge
Worn-out battery - Replace the battery
Battery cable harness damage - Check battery cables for damage, change or repair
Loose or corroded battery terminals and cables - Service or tighten battery terminals and cables
Improper belt tension adjustment or damaged belt - Replace belt or adjust belt tension correctly
Starter cranks slow
Low battery output - Low battery charging, charge as required
Battery will not hold charge - Service charging system or install new battery
Bad battery cable harness - Inspect cables for malfunctions, repair or change
Battery cables and terminals are loose or corroded - Service or tighten battery cables and terminals
Starter will not work
Low battery power - Recharge the battery
Discharged or faulty battery - Recharge or replace battery
Starter motor is defective - Starter should be replaced
Disconnected or incorrectly connected wiring harness - Inspect wiring harness and reconnect it as required

Transmission Troubleshooting
Hard to shift gears
Worn or incorrectly adjusted clutch - Adjust clutch or replace if required
Gear shift linkage is loose or broken - Repair or change shift linkage
Shift forks are damaged or worn - Replace the shift forks
Faulty parts in the gear shifting mechanism - Change faulty parts
Insufficient transmission oil pressure
Low transmission oil level - Fill the transmission housing to proper oil level
Transmission fluid filter clogging (if fitted) - Change or clean the transmission fluid filter
Faulty relief valve - Install a new relief valve
Transmission is excessively noisy
Bearings are worn or cracked - Replace the bearings
Lack of transmission fluid supply - Fill the transmission housing with fluid
Dirty transmission oil - Transmission oil must be changed
Incorrect backlash or gears are defective - Replace gears or set backlash correctly
Damaged or worn shift forks - Change defective shift forks
Transmission fluid leaking
Seals or gaskets are damaged - Replace worn gaskets or seal
Cracked transmission housing - Housing needs to be replaced

Hydraulics Troubleshooting
Excessive hydraulic system heat
Improper hydraulic system pressure setting - Set the pressure properly
Main relief valve is defective or unadjusted - Adjust the valve or replace if necessary
Contaminated hydraulic oil - Change hydraulic oil
Hydraulic system sucks air - Inspect the pump seals, suction pipe, and fittings
Insufficient hydraulic oil pressure
Hydraulic oil level is insufficient - Fill up the hydraulic oil
Hydraulic oil filter clogging - Clean or replace the hydraulic filter
Hydraulic pump is defective - Check the pump performance and replace it if required
Defective or not adjusted hydraulic control valve - Adjust properly or replace
Defective hydraulic cylinder - Check the hydraulic cylinder parts for damage or wear and replace if necessary
Hydraulic piping leaks - Inspect hydraulic system for leaks and repair it
3-point hitch won't raise or raises slowly
Lack of hydraulic oil - Fill the hydraulic system with oil
Hydraulic fluid is too cold - Allow fluid to warm
Hydraulic oil filter clogging - Service or replace the hydraulic filter
Defective hydraulic pump - Test pump performance and replace pump if necessary
Main relief valve is damaged or adjusted improperly - Adjust or change relief valve
Damaged or incorrect adjusted hydraulic control valve - Adjust properly or change
Faulty hydraulic cylinder - Check cylinder components for damage or wear and change if necessary
Broken or loose suction line - Retighten or change
Hitch does not lower or lowers very slowly
Hydraulic spool valve is faulty or out of adjustment - Replace or adjust properly
Faulty hydraulic cylinder - Check cylinder parts for wear or damage and replace if necessary
Worn hitch cross shaft - Replace the shaft
Internal mechanical failure of the hitch - Change worn or defective hitch components
Hitch is lowered or raised jerkily
Hydraulic system sucks air - Check the pump seals, suction line, and fittings
Hydraulic oil contamination - Change the oil
Faulty hydraulic oil pump - Check hydraulic pump flow and replace pump if necessary
Hydraulic spool valve is defective or set improper - Adjust correctly or change
Hydraulic cylinder failure - Check cylinder parts for wear or damage and replace if necessary

Steering System Troubleshooting
Steering wheel turns hard
Steering column is damaged or incorrectly assembled - Steering column must be assembled correctly or changed
Aeration in steering system - Bleed air from system
Improper toe-in adjustment - Check and adjust toe-in
Deflated front tyres - Inflate tyres as needed
Damaged hydraulic steering pump - Check the steering pump and replace if necessary
Hydrostatic steering unit has wear or damage - Inspect and replace as required
Relief valve failure or seizing - Replace or service relief valve
Steering fluid level is low - Check fluid level and add steering fluid as required
Steering system oil leak - Retighten joints of the hydraulic steering pipes and hoses
Excessive play in steering
Steering column shaft or coupling has maximum wear - Replace defective component
Worn or defective hydrostatic steering unit - Repair or replace the steering unit
Defective hydraulic steering pump - Replace or repair steering pump
Steering linkage or tie-rod ends are defective - Replace damaged part
Tractor is pulling to left or right
Tire pressure is improper - Inflate the tires properly
Incorrect toe-in adjustment - Adjust toe-in wheels properly
Faulty or worn steering tie-rod ends or linkage - Replace damaged component
Damaged or worn hydrostatic steering unit - Replace or repair steering unit as required
Steering cylinder failure - Repair or replace hydraulic steering cylinder
Front hub bearings are improperly adjusted or defective - Adjust correctly or replace bearings



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