Bobcat S76 Skid Steer Troubleshooting

The Bobcat S76 skid steer loader is powered by 146.5 cu.in (2.4L) Bobcat Doosan D24 four-cylinder turbocharged diesel engine with a rated power of 74 hp (55.2 kW) at 2600 rpm. The Bobcat S76 is equipped with a single-speed or two-speed hydrostatic transmission, vertical-lift loader boom, 120 HSOC roller chains, and 12x16.5 or 33-15.5x16.5 tires. The hydraulic system has a pump with fluid flow rate of 23.3 gpm (88.1 lpm). The hydraulic pressure is 3550 psi (245 bar). The skid steer has a rated operating capacity of 2900 lbs (1315 kg) and tipping load of 5800 lbs (2630 kg). The boom lifting force is 6685 lbs (3032 kg), and bucket breakout force is 5850 lbs (2654 kg).

Engine Troubleshooting

Diesel engine hard to start or doesn't start

Air in the fuel system - Air bleeding.
Fuel filter element is clogged - Install new filter element.
Fuel injection nozzles are damaged - Service or change injection nozzles.
Water or dirt in fuel system - Drain, flush, and service the system.
Valve out of adjustment - Adjust valve clearance.
Fuel injection pump failure - Replace or repair injection pump.

Engine starts and then shuts off

Air cleaner is clogged - Clean or change cleaner.
Fuel filter element is clogged - Clean or replace the filter.
Poor fuel injection pump tightness - Look for any leaks of fuel pump, tighten it fast.
Clogged or defective injectors - Replace or clean fuel injectors.
Fuel injection pump is defective - Replacement or repair required.

Engine stops running suddenly

Low coolant temperature - Warm up the engine.
Fuel filter element is dirty - Replace the filter element.
Air in the fuel pipes - Bleed the fuel pipes.
Dirty or faulty injection nozzles - Check and replace nozzles if required.
Fuel injection pump timing is wrong - Set up as recommended.

Engine shuts off while idling

Incorrectly set low idle speed - Test and adjust.
Fuel injection pump is not operating properly - Rebuild or install a new injection pump.
Clogged or defective injectors - Clean fuel injectors or change it.
Incorrect valve clearance - Correct valve clearance needs to be set.

Engine loses power

Air filter is dirty - Clean or change filter.
Fuel injection nozzles fault - Replace injection nozzles.
Fuel injection pressure is incorrect - Test fuel injection pressure and adjust it correctly.
Improper valve clearance - Check and adjust.
Incorrect low idle setting - Correct low idle adjustment.
Fuel hoses or lines clogging - Clean fuel hoses and lines.
Worn cylinder head gasket - Cylinder-head gasket replacement required.
Defective or worn piston rings - Piston rings need to be replaced.

Engine overheated

Lack of engine coolant - Top up coolant fluid and check system for leaks.
Not enough engine oil - Fill up the engine oil.
Dirty radiator fins or defective radiator cap - Change cap or clean radiator.
Damaged or worn fan belt - Replace as required.
Diesel engine overloaded - Load reducing required.

Insufficient oil pressure

Oil level is insufficient - Add oil as required.
Clogged oil filter - Change or clean engine oil filter element.
Improper type of engine oil - Fill up with the proper oil viscosity.
Incorrect oil clearance in main bearing - Bearing needs to be changed.
Defective oil pump - Check and replace if necessary.

Engine knocking sound or abnormal noise

Engine oil insufficient - Checking oil level and add if necessary.
Low coolant temperature - Warm up the engine.
Improper setting of fuel injection pump timing - Set it up as required.
Low idle speed set incorrectly - Adjust the low idle speed.
Dirty or defective injectors - Change or clean fuel injectors.
Connecting rod is misaligned or defective - Connecting rod needs to be aligned or changed.
Pistons are broken or worn - Have pistons replaced.

Drive System Troubleshooting

Machine does not move forward or backward

Insufficient hydraulic fluid - Check and refill the hydraulic fluid.
Drive chain is worn - Inspect drive chain and replace defective components.
Input drive shaft failure - Rebuild or change.
Relief valve defective or worn - Service or change relief valve.
Suction line or hydraulic filter is dirty - Clean suction line or change hydraulic filter.
Defective hand or foot controls - Inspect and repair if necessary.
Worn drive motor or pump - Repair or change faulty component.

Reduced power

Dirty hydraulic oil filter - Replace hydraulic filter.
Open or faulty relief valve - Close or replace relief valve.
Faulty or damaged transmission components - Check and change faulty components.
Stuck input drive shaft - Repair or replace faulty drive shaft.
There is air in the hydraulic system - Air bleeding is required.

Drive system is overheated

Low hydraulic fluid level - Fill up the hydraulic fluid.
Plugged hydraulic fluid filter - Replace or clean hydraulic filter.
Relief valve is damaged - Relief valve need to be replaced or repair.
Worn hydraulic motor or drive pump - Repair or change faulty component.
Plugged hydraulic oil cooler - Cooling fins should be cleaned.
Drive system is overloaded - Load should be reduced.

Drive system is excessively noisy

Oil viscosity is too heavy - Drain and refill with proper oil.
Air in hydraulic system - Air bleeding is required.
Drive pump or hydraulic motor malfunction - Replace or repair faulty component.
Mechanical components of drive system are damaged or worn - Inspect the parts for worn or defect and repair as needed.

Hydraulics Troubleshooting

Hydraulic system overheated

Hydraulic pressure is not correct - Hydraulic pressure must be set correctly.
Main relief valve failure or improper setting - Replace or set up the relief valve.
Dirty hydraulic fluid - Hydraulic fluid change required.
Hydraulic fluid level is low - Fill the hydraulic system with oil.
Worn hydraulic oil pump - Repair or install new hydraulic pump.

Lift arm can't drop or lift

Damaged lift controls - Inspect and repair if necessary.
Hydraulic pump malfunction - Change or repair hydraulic pump if required.
Hydraulic control valve is defective - Repair or change hydraulic valve.
Hydraulic cylinder malfunction - Repair or replace hydraulic cylinder.
Hydraulic fluid level low - Fill up the hydraulic fluid.

Bucket fails to tilt

Bucket tilt controls malfunction - Change or repair.
Damaged hydraulic oil pump - Repair or install new hydraulic pump.
Damaged hydraulic control valve - Install a new hydraulic valve or repair it.
Bucket cylinder is faulty - Repair or install a new cylinder.
Hydraulic oil is insufficient - Checking hydraulic oil level and add if necessary.

Bucket or lift arm runs slowly

Hydraulic pump is faulty - Test the pump flow rate and change pump if required.
Hydraulic cylinder leaking - Install new cylinder seals.
Low hydraulic fluid level - Fill the system to proper hydraulic fluid level.
Defective or not adjusted hydraulic control valve - Set properly or repair.
Hydraulic pressure is low - Adjust it correctly.

Bucket or boom is working jerkily

Air in hydraulic system - Bleed air from system.
Hydraulic oil filter is clogged - Clean or install new filter.
Hydraulic oil contamination - Hydraulic oil change required.
Cylinder tube or rod is scored - Replace worn component.

Excessive hydraulic pump noise

Hydraulic leaks or lack of oil - Top up hydraulic oil or remedy leakage in system.
Hydraulic filter is dirty - Service or change hydraulic filter.
Suction line is clogged - Need to clean the suction line.
Air trapped in hydraulic pump - Air bleeding is required.
Pump components are damaged - Replace or rebuild the pump.

Electrical Troubleshooting

Battery cannot be charged

Loose or corroded electrical wiring connections - Tighten or service connections.
Battery terminal clamps are faulty - Terminal clamps need to be replaced.
Battery bad cell - Change the battery.
Loose or worn belt - Adjust belt tension or change the belt.

Starter turns slow

Battery capacity is low - Battery is drained, charge it.
Battery discharges quickly - Service charging system or install new battery.
Corroded battery terminals or disconnected wires - Connect wiring properly or install new terminals.

Starter will not work

Battery is drained or defective - Recharge or replace battery.
Wiring is incorrectly connected or disconnected - Inspect wiring and connect correctly.
Battery voltage is low - Charge the battery.
Damaged starter motor - Repair or change starter.