Bobcat T770 Track Loader Troubleshooting

The Bobcat T770 compact track loader driveline system components: a 230 cu.in (3.8L) Kubota V3800-DI-TE3 4-cylinder turbocharged liquid-cooled diesel engine with a rated power of 88.1 hp (65.6 kW), and one-speed or two-speed hydrostatic transmission. The hydraulic system has a pump with a rated capacity of 23 gal/min (87.1 l/min). The system pressure is 3550 psi (245 bar). The Bobcat T770 is equipped with hydraulic disc brakes and rubber tracks with steel inserts. The compact track loader has a lift height of 132" (3350 mm) to hinge pin and dump height of 104.3" (2650 mm). The rated operating capacity is 3135 lbs (1420 kg), and tipping load is 8960 lbs (4065 kg).

Engine Troubleshooting

Engine starts hard or will not start

There is air in the fuel system - Bleed the system.
Fuel filter plugging - Filter maintenance required.
Dirty or damaged injection nozzles - Service or change injection nozzles.
Water or dirt in fuel system - Drain, flush, and service the system.
Valve clearance is wrong - Correct valve clearance needs to be set.
Fuel injection pump is broken - Rebuild or change fuel pump.

Engine starts and stalls suddenly

Air filter is clogged - Replace or clean air filter element.
Clogged fuel filter - Change filter element.
Fuel injection pump is leaking - Repair any leaks.
Damaged or clogged injectors - Clean fuel injectors or change it.
Fuel injection pump failure - Repair or replace injection pump.

Engine shuts off suddenly while running

Engine has not warmed up to the recommended temperature - Warm up engine as required.
Dirty fuel filter - Clean or change the filter.
Air in fuel system - Bleed fuel system.
Fuel injection nozzles are clogged or faulty - Replace injection nozzles.
Timing of fuel injection pump is incorrect - Adjust according to specifications.

Engine stalls while idle

Incorrect low idle setting - Normalize low idle speed.
Fuel injection pump is damaged - Replace or rebuild injection pump.
Fuel injectors are faulty or clogged - Inspect fuel injectors and change as required.
Excessive valve clearance - Adjust to proper valve clearance.

Lack of engine power

Air filter is clogged - Clean or change filter.
Fuel injection nozzles are damaged - If necessary, replace with a new nozzle.
Improper fuel injection pressure - Test fuel injection pressure and adjust it correctly.
Improper valve clearance - Adjust valve clearance.
Too low idle RPM - Adjust low idle speed.
Dirt in the fuel lines or hoses - Fuel lines and hoses need to be cleaned.
Damaged cylinder-head gasket - Replace the gasket as required.
Defective or worn piston rings - Change piston rings.

Engine is overheated

Insufficient coolant fluid - Add coolant and check the components of cooling system.
Low engine oil level - Check oil level and add oil as required.
Dirty radiator fins or defective radiator cap - Clean radiator or replace cap.
Loose or defective fan belt - If necessary, replace the belt.
Diesel engine overloaded - Load reducing required.

Low oil pressure

Lack of oil - Add oil as required.
Oil filter is clogged - Service or change engine oil filter element.
Incorrect oil viscosity - Use the specified type of engine oil.
Excessive crankshaft bearing oil clearance - Install new bearings.
Defective oil pump - Inspect and change as required.

Engine noises or knocks

Not enough engine oil - Check and refill engine oil.
Low coolant temperature - Warm up the engine.
Wrong setting of fuel injection pump timing - Use the correct fuel injection pump timing adjustment.
Incorrectly set low idle speed - Correct low idle adjustment.
Defective fuel injectors - Replace fuel injectors.
Connecting rod is not aligned or worn - Align or change connecting rod.
Piston wear or scoring - Replace the pistons.

Drive System Troubleshooting

Machine is not moving in one direction or either direction

Hydraulic fluid is insufficient - Fill up the hydraulic fluid.
Jammed or damaged track mechanism - Fix jamming or repair tracks.
Faulty relief valve - Relief valve need to be replaced or repair.
Suction line or hydraulic filter is dirty - Change hydraulic filter or service suction line.
Defective foot or hand controls - Repair or replace.
Drive motor or pump is defective - Change or repair faulty component.

Machine will not drive straight or drives jerky

Damaged or jammed undercarriage tracks - Repair or remove jamming.
Tracks are loose or worn - Adjust track tension properly or repair tracks.
Debris, dirt, or foreign objects stuck in undercarriage track frame - Clean track frame, remove debris.

Power is too low

Hydraulic oil filter is clogged - Change or clean hydraulic filter.
Relief valve is defective or open - Change or close relief valve.
Transmission components are damaged or faulty - Check and change defective components.
Defective input drive shaft - Replace or service the drive shaft.
Air trapped in hydraulic system - Bleed air from hydraulic system.

Drive system keeps overheating

Hydraulic fluid level low - Check and refill the hydraulic fluid.
Hydraulic fluid filter is clogged - Change or clean hydraulic filter.
Relief valver is broken - Repair or replace relief valve.
Defective drive pump or hydraulic motor - Inspect and change as required.
Hydraulic oil cooler is dirty - Cooling fins should be cleaned.
Drive system overload - Load should be reduced.

Drive system is noisy

Oil viscosity is wrong - Drain and refill with correct oil.
There is air in the hydraulic system - Need to bleed air.
Hydraulic motor or drive pump failure - Check and repair if required.
Mechanical parts of drive system are worn or damaged - Check the parts and replace if required.

Hydraulics Troubleshooting

Hydraulic system is overheated

Hydraulic pressure is not correct - Correct setting is required.
Main relief valve is damaged or adjusted improperly - Adjust relief valve or change if required.
Hydraulic oil contamination - The oil must be changed.
Hydraulic fluid level is insufficient - Add fluid to the hydraulic system.
Hydraulic pump is defective - Repair or change pump if required.

Boom can't lift or drop

Lift controls are defective - Inspect and repair if necessary.
Hydraulic pump is broken - Change or repair hydraulic pump if required.
Hydraulic control valve failure - Install a new valve or repair it.
Damaged hydraulic cylinder - Repair or change hydraulic cylinder.
Hydraulic fluid is insufficient - Checking hydraulic fluid level and add if necessary.

Bucket won't move

Bucket tilt controls are damaged - Repair or replace.
Damaged hydraulic oil pump - Replace or repair pump if necessary.
Faulty hydraulic control valve - Install a new hydraulic valve or repair it.
Broken bucket cylinder - Repair or install a new cylinder.
Low hydraulic oil level - Check and refill the hydraulic oil.

Boom or bucket moves slowly

Faulty hydraulic oil pump - Test pump performance and replace pump if necessary.
Hydraulic cylinder oil leakage - Repair leak by replacing the seals.
Insufficient hydraulic oil - Checking hydraulic oil level and add if necessary.
Faulty or incorrect setting hydraulic control valve - Adjust properly or repair.
Hydraulic system loosing pressure - Hydraulic pressure must be set correctly.

Bucket or boom is working jerkily

Air in the hydraulic system - Bleed hydraulic system.
Hydraulic oil filter clogging - Replace or clean the filter.
Hydraulic oil is contaminated - Change hydraulic oil.
Cylinder tube or rod is scored - Change worn component.

Excessive hydraulic pump noise

Insufficient oil level or leaking hydraulic system - Add hydraulic oil or correct system leaks.
Dirty hydraulic filter - Clean or install new filter.
Suction line clogging - Service the suction line.
Pump sucks air - Remove air from hydraulics.
Worn pump components - Change or rebuild pump.

Electrical Troubleshooting

Battery is not charging

Loose or corroded cable connections - Tighten or service cable connections.
Faulty electrical terminal connectors - Terminal connectors need to be changed.
Battery bad cell - Use a new battery.
Loose or damaged belt - Adjust belt tension or change the belt.

Starter cranks slowly

Battery voltage is low - Charge the battery.
Battery is draining quickly - Service battery or change it.
Disconnected wiring or bad battery terminals - Check cables and service or change terminals.

Starter will not work

Battery is discharged or worn - Recharge or replace battery.
Wiring is incorrectly connected or disconnected - Inspect wiring and connect correctly.
Low battery voltage - Recharge the battery.
Starter motor failure - Starter needs to be changed.