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Kubota M6800 Troubleshooting
The
Kubota M6800 is a 2-wheel drive or 4-wheel drive utility tractor from M-Series.
This model was manufactured between 1997 and 2005. The Kubota M6800 driveline
includes a V3300 four-cylinder water-cooled diesel engine and 8x8 synchronized
shuttle transmission, or power shuttle transmission with 8 forward and 8 reverse
gears.
A 3.3L (202 cu.in) engine power is 70.9 hp (52.9 kW) at 2600 rev/min.
The maximum forward/reverse speed - 20.7 mph (33.3 km/h). The open
center hydraulic system includes a gear pump with a rated fluid flow of 11
gpm (41.6 lpm).
The main relief pressure is 195 bar (2830 psi). The standard lift capacity
is 4200 lbs (1905 kg). The 2WD models are equipped with 7.50x16 front
tyres and 16.9-30 rear tyres. The 9.50x24 front tyres and 16.9-30 rear
tyres fit 4WD tractors. The wheelbase is 80.7 in (2040 mm) for models
without cab and 83.7 in (2120 mm) for models with cab. The Kubota M6800
is compatible with LA1002 front end loader with a maximum lift height of
115.6 in (2930 mm), and LA1162 front end loader with a maximum lift
height of 114 in (2890 mm).
Engine Troubleshooting |
Engine doesn't start or hard to start |
Fuel filter plugging - Replace the 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 defective or dirty - Service or change fuel injectors |
Fuel injection pump malfunction - Repair or install new pump |
Bad engine compression - Inspect cylinder block and replace worn components |
Engine stalls during operation |
Engine not warmed up - Warm up to required temperature |
Air in fuel lines - Bleed fuel lines |
Uneven fuel injections - Repair or adjustment |
Plugged fuel filter - Clean the filter element |
Faulty or dirty injectors - Change fuel injectors |
Engine starts and then stalls |
Fuel injection pump out of timing - Adjust injection timing |
Fuel filter is dirty - Change the filter element |
Fuel injector nozzles are dirty or defective - Inspect injector nozzles and change if required |
Fuel injection pump is broken - Rebuild or change fuel pump |
Clogged air cleaner - Replace cleaner or install new cleaner element |
Engine stalls when idling |
Too low idle RPM - Normalize low idle speed |
Damaged fuel injection pump - Rebuild or replace pump |
Clogged or defective injector nozzles - Check and change nozzles as required |
Valve clearance is not correct - Adjustment procedure required |
Engine has a lack of coolant - Top up coolant. Check and repair damage to the cooling system if required |
Cooling system is clogged or cooling parts are defective - Replace faulty parts or service cooling system |
Not enough engine oil - Need to add engine oil |
Fan belt is worn or belt tension is improper - Adjust belt tension properly or change it |
Thermostat fault - Check and replace if required |
Engine power is insufficient |
Dirty or faulty injectors - Clean or replace fuel injectors |
Insufficient fuel injection pressure - Adjust pressure to proper level |
Air filter is dirty - Replace or clean the air filter element |
Oil filter clogging - Clean or change engine oil filter |
Engine is running overloaded - Load reducing required |
Incorrect valve clearance - Check and adjust |
Incorrectly adjusted low idle speed - Correct the settings |
Fuel hoses or pipes clogging - Service fuel pipes and hoses |
Engine compression too low: Valves are broken or leaking - Replace the valves |
Engine knocking sound or abnormal noise |
Incorrectly set fuel injection pump timing - Check and correct settings |
Fuel injector nozzles are faulty - Change injector nozzles |
Engine oil insufficient - Check oil level and add oil as required |
Engine is not preheated - Warm up the engine |
Main bearings or crankshaft wear - Crankshaft or bearings need to be replaced |
Piston rings failure - Have piston rings replaced |
Flywheel mounting screws are loose - Tighten the screws |
Engine consuming too much oil |
External oil leaks: Worn seals or gaskets - New components need to be installed |
Oil viscosity is incorrect - Use oil of correct viscosity |
Piston rings are stuck or worn - Have piston rings replaced |
Worn valve stems and valve guides - Install new valves |
Scored cylinder liners or pistons - Check pistons and liners, change as required |
Electrical System Troubleshooting |
Battery won’t charge |
Battery bad cell - Replace the battery |
Battery wiring harness damage - Inspect battery wiring for damage, replace or repair |
Corroded or loose cables and terminals - Tighten or service terminals and cables |
Defective belt or improperly adjusted belt tension - Adjust belt tension correctly or replace belt |
Low battery output voltage - Battery is drained, charge it |
Battery won’t hold charge - Battery needs service or replacement |
Damaged battery electrical wire harness - Inspect electrical wires for damage, change or repair |
Loose or corroded cables and terminals - Service or tighten battery terminals and cables |
Battery power is low - Charge the battery |
Discharged or worn battery - Need to charge or replace the battery |
Starter motor failure - Starter needs to be replaced |
Improperly connected or disconnected wiring harness - Inspect wiring harness and connect properly |
Transmission Troubleshooting |
Hard shifting |
Failure or improper clutch adjustment - Adjust clutch or change if necessary |
Stuck or damaged gear shift linkage - Repair or change shift linkage |
Damaged or worn shift forks - Shift forks need to be replaced |
Faulty gear shifting mechanism - Faulty parts must be changed |
Transmission oil pressure is insufficient |
Oil level is low - Correct the transmission oil level |
Clogged transmission fluid filter element (if fitted) - Clean or replace the transmission fluid filter |
Relief valve failure - Install a new relief valve |
Excessive transmission noise |
Bearings are worn or cracked - Install new bearings |
Fluid level is low - Fill system with correct transmission fluid level |
Dirty transmission oil - Change transmission oil |
Damaged gears or improper backlash - Set backlash correctly or change the gears |
Worn or damaged shift forks - Replace defective shift forks |
Gaskets or seals are defective Replace worn seal or gaskets |
Transmission housing is cracked - Replace housing or transmission assembly |
Hydraulics Troubleshooting |
Hydraulic system is too hot |
Hydraulic system pressure is unadjusted - Adjust the pressure as required |
Defective or misadjusted main relief valve - Replace or set up the relief valve |
Contaminated hydraulic fluid - Change hydraulic fluid |
Air leaks in hydraulic system - Inspect the suction pipe, fittings, and pump seals |
Low hydraulic fluid pressure |
Lack of hydraulic oil - Fill up the hydraulic oil |
Hydraulic fluid filter clogging - Clean or change hydraulic filter |
Hydraulic pump is defective - Flow-rate pump and change pump if necessary |
Hydraulic control valve block is faulty or out of adjustment - Replace or set correctly |
Hydraulic cylinder failure - Check the hydraulic cylinder parts for damage or wear and replace if necessary |
Leakage in hydraulic pipes - Find leaks in hydraulic system and repair it |
3-point hitch does not raise or raises very slowly |
Lack of hydraulic oil - Add oil to the hydraulic system |
Cold oil in hydraulic system - Wait for oil to warm up |
Hydraulic oil filter clogging - Install a new hydraulic filter element |
Hydraulic pump is faulty - Test the pump performance and change pump if required |
Unadjusted or defective main relief valve - Adjust or replace the relief valve |
Defective or not adjusted hydraulic control valve - Adjust properly or change |
Hydraulic cylinder is not working - Check cylinder components for wear or damage and change if necessary |
Damaged or loose hydraulic suction line - Tighten or change it |
Hitch won't lower or lowers slowly |
Defective or not adjusted hydraulic control valve - Replace or set properly |
Faulty hydraulic cylinder - Inspect the hydraulic cylinder components for damage or wear and change if required |
Damaged lift arm shaft - Replace the shaft |
The hitch has mechanical faults - Replace worn or defective hitch components |
Three-point hitch raises or lowers not smoothly |
Air trapped in the hydraulic system - Inspect the suction pipe, fittings, and pump seals |
Hydraulic fluid is dirty - Hydraulic fluid change required |
Damaged hydraulic oil pump - Test pump performance and replace pump if necessary |
Defective or not adjusted hydraulic spool valve - Set properly or replace |
Hydraulic cylinder is defective - Check cylinder components for damage or wear and change if necessary |
Steering System Troubleshooting |
Steering wheel is hard to turn |
Steering column is broken or incorrectly fitted - Steering column needs to be refit correctly or replaced |
Air leaks in steering system - Air-bleed steering system |
Improper toe-in adjustment - Adjust toe-in correctly |
Tires are incorrectly inflated - Inflate as required |
Steering pump not working - Check the steering pump and replace if necessary |
Worn or damaged hydrostatic steering unit - Inspect and replace as required |
Relief valve is stuck or defective - Inspect relief valve and replace if necessary |
Lack of steering fluid - Need to add steering oil |
Steering system oil leak - Tighten connections of hydraulic hoses and pipes in steering system |
Excessive steering wheel free play |
Steering column coupling or shaft is worn - Replace faulty component |
Worn or defective hydrostatic steering unit - Inspect and change as required |
Hydraulic steering pump is defective - Check the steering pump and replace if necessary |
Steering tie-rod ends or linkage are worn - Change failed component |
Tractor pulls to left or right |
Low tire pressure - Inflate the tires |
Not adjusted toe-in - Adjust toe-in properly |
Steering tie-rod ends or linkage are worn - Change failed part |
Worn or defective hydrostatic steering unit - Replace or repair steering unit as required |
Steering cylinder is damaged - Repair or replace steering cylinder |
Incorrectly adjusted or worn front hub bearings - Change or adjust bearings correctly |
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Farm Tractors Technical Specifications |