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Bobcat M611 Troubleshooting

The Bobcat 611 skid steer loader driveline system components: a 85.2 cu.in (1.4L) Deutz F2L411 4-cycle 2-cylinder air-cooled diesel engine with a rated power of 27.5 hp (20.5 kW), and variable sheave transmission. The hydraulic system has a pump with a rated capacity of 8.7 gal/min (32.1 l/min). The system relief pressure is 1700 psi (117 bar). The Bobcat 611 is equipped with a radial-lift loader boom, 60H drive chains, and 7.00x15 standard tires. The skid steer loader has a maximum lift height of 108" (2745 mm) to hinge pin and dump height of 86" (2185 mm). The rated operating capacity is 1000 lbs (454 kg), and tipping load is 2100 lbs (955 kg).

Engine Troubleshooting

Engine difficult to start or won't start
Air trapped in fuel system - Bleed air.
Fuel filter plugged - Replace the filter element.
Dirty or faulty injection nozzles - Test injection nozzles and change if necessary.
Water or dirt in fuel system - Drain, flush, and service the system.
Excessive valve clearance - Adjustment procedure required.
Fuel injection pump failure - Rebuild or replace pump.

Diesel starts and stalls immediately
Plugged air cleaner - Install new air cleaner element.
Fuel filter element is clogged - Replace the filter element.
Problems with fuel injection pump tightness - Inspect fuel injection pump for leaks.
Dirty or defective injectors - Replace fuel injectors.
Damaged fuel injection pump - Rebuild or change fuel pump.

Engine shuts off while running
Low coolant temperature - Normalize the temperature by warming up the engine.
Clogged fuel filter - Change filter element.
Air in fuel system - Bleed fuel system.
Defective injection nozzle - Test injection nozzles and change if necessary.
Incorrect adjustment of fuel injection pump timing - Adjust according to specifications.

Engine stalls at low idle speed
Low idle speed set incorrectly - Adjust low idling as recommended.
Fuel injection pump is damaged - Replace or rebuild injection pump.
Fuel injectors are faulty or clogged - Change or clean fuel injectors.
Valve clearance is not correct - Adjustment procedure required.

Engine power is too low
Plugged air cleaner - Clean or replace air cleaner element.
Clogged injection nozzle - Change fuel injection nozzles.
Fuel injection pressure is incorrect - Adjust to proper pressure.
The valve clearance is not adjusted - Check and adjust.
Too low idle RPM - Adjust low idling as recommended.
Fuel lines or hoses are dirty - Fuel lines and hoses need to be cleaned.
Cylinder head gasket is damaged - Install a new gasket.
Worn or broken piston rings - Piston rings replacement required.

Engine overheats
Lack of coolant in cooling system - Fill the cooling system and check components for leaks or other faults.
Engine oil insufficient - Add oil to the engine crankcase.
Faulty radiator cap or dirty radiator fins - Replace cap or clean radiator.
Damaged or worn fan belt - Belt replacement is recommended.
Engine overloaded - Load reducing is recommended.

Low oil pressure
Not enough oil in the engine - Check and refill the oil.
Oil filter element clogged - Clean or replace engine oil filter element.
Incorrect oil viscosity - Use the specified type of engine oil.
Crankshaft bearing has incorrect oil clearance - Bearings need to be reinstalled.
Worn oil pump - Replace as required.

Engine knocking sound or abnormal noise
Engine oil insufficient - Fill the crankcase with engine oil.
Low coolant temperature - Warm up the engine.
Incorrect adjustment of fuel injection pump timing - Set it up as required.
Incorrect low idle speed adjustment - Correct the settings.
Clogged or defective injectors - Replace fuel injectors.
Misaligned or defective connecting rod - Connecting rod needs to be replaced or aligned.
Worn or scored pistons - Install new pistons.

Drive System Troubleshooting

Machine will not move in either direction or one direction
Hydraulic oil is insufficient - Need to add oil.
Relief valve is not working correctly - Repair or change.
Plugged suction line or hydraulic filter - Change hydraulic filter or service suction line.
Foot or hand controls are faulty - Repair or replace.
Defective transmission components - Check and repair if required.

Loss of power
Clogged hydraulic oil filter - Replace or service hydraulic filter.
Transmission components are worn or defective - Inspect and replace faulty parts.
Input drive shaft is worn - Replace drive shaft.
Air in hydraulic system - Bleed air from system.

Drive system overheats
Hydraulic oil level is low - Need to add oil.
Hydraulic fluid filter is dirty - Replace hydraulic filter.
Relief valve is stuck - Change or repair defective relief valve.
Transmission components are worn - Repair or change faulty component.
Drive system is overloaded - Load needs to be reduced.

Drive system is noisy
Oil viscosity is wrong - Use correct oil viscosity.
Air in hydraulic system - Need to bleed air.
Transmission components are worn - Change or repair faulty component.
Defective or worn mechanical components of drive system - Check the components for worn or defect and replace if necessary.

Hydraulics Troubleshooting

Hydraulic system is overheated
Hydraulic pressure is not adjusted correctly - Adjust pressure correctly.
Main relief valve is defective or unadjusted - Adjust relief valve or change if required.
Dirty hydraulic oil - Fill up with fresh hydraulic oil.
Lack of hydraulic fluid - Check and refill the hydraulic fluid.
Hydraulic pump is defective - Replace or repair pump if necessary.

Lift arm fails to drop or lift
Lift controls are defective - Change or repair.
Hydraulic pump malfunction - Replace or repair pump if necessary.
Defective hydraulic control valve - Replace or repair the valve.
Hydraulic cylinder failure - Install a new boom cylinder or repair it.
Hydraulic fluid is insufficient - Add fluid as required.

Bucket won't move
Bucket tilt controls are defective - Check and repair as required.
Hydraulic pump not working - Repair or replace pump if necessary.
Faulty hydraulic control valve - Install a new valve or repair it.
Hydraulic bucket cylinder is defective - Install a new cylinder or repair it.
Low hydraulic oil level - Fill the system to proper hydraulic oil level.

Bucket or lift arm moves slowly
Faulty hydraulic oil pump - Flow-rate pump and change pump if necessary.
Hydraulic cylinder oil leakage - Replace cylinder piston seals.
Hydraulic fluid level low - Fill up the hydraulic fluid.
Hydraulic control valve is defective or set improper - Repair or adjust correctly.
Hydraulic pressure is low - Set pressure correctly.

Bucket or boom is moving jerkily
Hydraulic system is leaking air - Bleed air from system.
Hydraulic oil filter element clogging - Replace or clean the filter.
Hydraulic fluid contamination - Change hydraulic fluid.
Cylinder tube or rod is scored - Change failed component.

Hydraulic pump makes excessive noise
Insufficient oil level or leaking hydraulic system - Correct hydraulic leaks or top up oil as needed.
Plugged hydraulic filter - Change or clean oil filter.
Dirty suction line - Suction line needs to be cleaned.
Air in hydraulic pump - Air bleeding is required.
Faulty pump parts - Install new hydraulic pump or rebuild it.

Electrical Troubleshooting

Battery is not charging
Corroded or loose wire connections - Clean or tighten connections.
Faulty battery terminal clamps - Terminal clamps need to be replaced.
Battery dead cell - Battery change required.
Worn or loose belt - Install a new belt or adjust belt tension.

Starter motor turns slow
Battery capacity is low - Battery needs to be recharged.
Battery does not hold charge - Service charging system or install new battery.
Corroded battery terminals or disconnected wires - Check wire connections and change or service terminals.

Starter does not work
Battery is discharged or defective - Charge or change the battery.
Wire harness is disconnected or incorrectly connected - Check wire harness and connect as required.
Low battery voltage - Charge the battery.
Starter motor is defective - Starter should be changed.