Bobcat T740 Track Loader Troubleshooting

The Bobcat T740 compact track loader driveline system components: a 208.1 cu.in (3.4L) Bobcat Doosan D34 4-cylinder turbocharged diesel engine with a rated power of 74 hp (55 kW), and 1-speed or 2-speed hydro transmission. The hydraulic system has a pump with a rated flow of 23 gpm (87.1 lpm). The system pressure is 3550 psi (245 bar). The Bobcat T740 is equipped with a vertical-lift loader boom, solid-mounted or roller suspension undercarriage, and rubber tracks. The loader has a max lift height of 132" (3350 mm) to hinge pin and dump height of 104.3" (2650 mm). The rated operating capacity is 3200 lbs (1450 kg), and tipping load is 9143 lbs (4147 kg).

Engine Troubleshooting

Engine starts hard or will not start

Air in the fuel system - Air bleeding.
Dirty fuel filter - Service or replace the filter.
Fuel injection nozzles are damaged - Install a new kit of correctly balanced nozzles.
Water or dirt in fuel system - Drain, flush, and service the system.
The valve clearance is incorrect - Adjust valve clearance according to specifications.
Fuel injection pump damage - Replacement or repair required.

Engine starts and immediately shuts off

Plugged air cleaner - Install new air cleaner element.
Fuel filter plugged - Change or clean the filter element.
Fuel injection pump is leaking - Repair any leaks.
Dirty or defective injectors - Clean or replace fuel injectors.
Defective fuel injection pump - Repair or change injection pump.

Engine shuts off suddenly while running

Low coolant temperature - Warm up the engine.
Dirty fuel filter - Clean the filter or install new filter element.
There is air in the fuel system - Bleed the system.
Defective or clogged injection nozzle - Check and replace nozzles if required.
Timing of fuel injection pump is incorrect - Adjust the pump as required.

Engine stalls while idling

Low idle speed set incorrectly - Test and adjust.
Fuel injection pump is faulty - Change or repair the pump.
Fuel injector fault - Change or clean fuel injectors.
Valve out of adjustment - Check and adjust.

Engine power is insufficient

Clogged air filter - Clean or change filter.
Clogged injection nozzle - Check injection nozzles and replace if required.
Insufficient fuel injection pressure - Adjust to correct pressure.
The valve clearance is not adjusted - Adjust valve clearance according to specifications.
Incorrectly adjusted low idle speed - Need to adjust idle speed.
Clogged fuel lines or hoses - Clean fuel hoses and lines.
Leaking cylinder head gasket - Install new cylinder head gasket.
Piston rings are worn or damaged - Replace piston rings.

Engine overheating

Insufficient coolant fluid - Refill to the correct level and inspect system for leaks.
Engine oil insufficient - Check and refill engine oil.
Clogged radiator core or leaking radiator cap - Install new cap or clean radiator.
Loose or damaged fan belt - Change the fan belt.
Engine overload - Load reducing is recommended.

Oil pressure is low

Engine oil insufficient - Fill the crankcase with oil.
Oil filter clogged - Replace or clean engine oil filter element.
Incorrect oil viscosity - Use proper viscosity oil.
Excessive main bearing oil clearance - Bearing needs to be changed.
Oil pump is worn or damaged - Repair or change.

Engine knocking or noise

Engine oil level low - Checking oil level and add if necessary.
Low coolant temperature - Warm up the engine.
Timing of fuel injection pump is incorrect - Adjust the pump as required.
Improperly adjusted low idle speed - Normalize low idle speed.
Fuel injector fault - Replace fuel injectors.
Connecting rod failure or misalignment - Align or replace connecting rod.
Pistons are worn or broken - Install new pistons.

Drive System Troubleshooting

Machine is not moving in one direction or either direction

Low hydraulic oil level - Check and refill the hydraulic oil.
Damaged or jammed undercarriage tracks - Fix jamming or repair tracks.
Relief valve is damaged - Repair or replace relief valve.
Hydraulic filter or suction line is plugged - Clean suction line or change hydraulic filter.
Foot or hand controls are damaged - Change or repair.
Worn drive motor or pump - Replace or repair faulty component.

Machine is not moving straight or moving is jerky

Damaged or jammed undercarriage tracks - Repair or fix jamming.
Sagging or faulty tracks - Correct track sag with tensioning or repair tracks.
Undercarriage track frame is plugged with dirt, debris, or foreign objects - Remove foreign objects or debris and clean undercarriage track frame.

Reduced power

Hydraulic oil filter is plugged - Check, clean, or change as necessary.
Relief valve is defective or opened - Close or change relief valve.
Faulty or damaged transmission components - Inspect and change defective parts.
Input drive shaft failure - Repair or install a new drive shaft.
Air in hydraulic system - Bleed air from system.

Drive system is overheated

Hydraulic fluid level low - Checking hydraulic fluid level and add if necessary.
Hydraulic fluid filter is dirty - Replace hydraulic filter.
Relief valve is worn or damaged - Rebuild or install a new relief valve.
Worn hydraulic motor or drive pump - Replace or repair faulty component.
Dirty oil cooler - Clean cooling fins as required.
Drive system is overloaded - Reduce the load.

Drive system makes excessive noise

Improper oil viscosity - Drain and refill with proper oil.
Air in the hydraulic system - Bleed air from system.
Damaged drive pump or hydraulic motor - Inspect and change as required.
Mechanical components of drive system are defective or worn - Inspect the parts for defect or damage and repair as required.

Hydraulics Troubleshooting

Hydraulic system is overheated

Incorrect hydraulic pressure setting - Adjust it correctly.
Defective or misadjusted main relief valve - Set up or change the relief valve.
Hydraulic fluid contamination - The fluid must be changed.
Lack of hydraulic fluid - Need to add fluid.
Faulty hydraulic oil pump - Install new pump or repair it.

Boom does not raise or lower

Lift controls are faulty - Replace or repair.
Hydraulic pump failure - Change or repair hydraulic pump if required.
Defective hydraulic control valve - Install a new valve or repair it.
Broken hydraulic cylinder - Install a new boom cylinder or repair it.
Hydraulic oil level low - Check and refill the hydraulic oil.

Bucket can't tilt

Bucket controls are faulty - Inspect and repair if necessary.
Hydraulic pump is broken - Repair or install new hydraulic pump.
Damaged hydraulic control valve - Install a new hydraulic valve or repair it.
Bucket cylinder failure - Change or repair cylinder.
Hydraulic oil is insufficient - Need to add oil.

Boom or bucket is moving slowly

Worn hydraulic oil pump - Check hydraulic pump flow and replace pump if necessary.
Hydraulic cylinder oil leakage - Correct leakage by changing the seals.
Hydraulic oil level low - Fill the system to proper hydraulic oil level.
Worn or unadjusted hydraulic control valve - Repair or set correctly.
Hydraulic pressure is low - Adjust it correctly.

Lift arm or bucket is moving jerkily

There is air in the hydraulic system - Bleed hydraulic system.
Hydraulic oil filter clogging - Clean or install new filter.
Contaminated hydraulic fluid - Fill up with fresh hydraulic fluid.
Scored cylinder tube or rod - Replace damaged component.

Hydraulic pump makes excessive noise

Hydraulic leaks or lack of oil - Correct hydraulic leaks or top up oil as needed.
Clogged hydraulic filter - Clean or install new filter.
Dirty suction line - Need to clean the suction line.
Pump sucks air - Need to bleed air.
Pump components are worn out - Change or rebuild pump.

Electrical Troubleshooting

Battery will not charge

Loose or corroded cable connections - Tighten or clean connections.
Defective battery terminal clamps - Install new terminal clamps.
Worn-out battery - Install a new battery.
Worn or loose belt - Adjust belt tension or replace belt.

Starter cranks slow

Low battery output - Battery needs to be recharged.
Battery is draining quickly - Battery needs to be serviced or replaced.
Wires are disconnected or battery terminals are corroded - Check cables and service or change terminals.

Starter will not work

Battery is low or faulty - Need to charge or replace the battery.
Wiring is improperly connected or disconnected - Check wiring and connect properly.
Low battery output voltage - Recharge the battery.
Starter motor failing - Starter needs to be replaced.