Bobcat S70 Skid Steer Troubleshooting

The Bobcat S70 skid steer loader is powered by 61.1 cu.in (1L) Kubota D1005-E3B vertical 3-cylinder indirect injection water-cooled diesel engine with a rated power of 22.5 hp (16.8 kW) at 3000 rpm. The Bobcat S70 is equipped with a single-speed hydrostatic transmission, hydraulic wet disc brakes, and 23x5.7-12 standard tires. The hydraulic system has a pump with fluid flow rate of 8.9 gpm (33.7 lpm). The hydraulic pressure is 3000 psi (207 bar). The skid steer loader has a rated operating capacity of 700 lbs (318 kg) and tipping load of 1512 lbs (686 kg). The boom lifting force is 1935 lbs (880 kg), and bucket breakout force is 1950 lbs (886 kg).

Engine Troubleshooting

Engine starts up hard or will not start

Air in the fuel pipes - Bleed the fuel pipes.
Clogged fuel filter - Install new filter element.
Clogged or burnt injection nozzle - Replace injection nozzles.
Dirt or water in fuel system - Drain water or flush dirt from the system.
Valve clearance is not correct - Adjust valve clearance according to specifications.
Fuel injection pump malfunctioning - Install a new fuel pump or repair.

Engine stalls after starting

Plugged air filter - Clean or replace element.
Fuel filter element is clogged - Replace the filter element.
Problems with fuel injection pump tightness - Inspect fuel injection pump for leaks.
Defective or clogged fuel injectors - Replace fuel injectors.
Fuel injection pump is not working correctly - Repair or replace injection pump.

Engine shuts off while running

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

Engine stops at low idle speed

Improperly adjusted low idle speed - Correct low idle settings.
Faulty fuel injection pump - Replace or repair injection pump.
Dirty or defective injectors - Replace fuel injectors.
Incorrect valve clearance - Check and adjust as required.

Diesel power loss

Dirty air filter - Service or replace the air filter.
Damaged or dirty injection nozzles - Install a new kit of correctly balanced nozzles.
Uneven fuel injection pressure - Adjust to proper pressure.
Incorrect valve clearance - Need to adjust valve clearance.
Incorrectly set low idle speed - Correct the settings.
Fuel hoses or lines are dirty - Fuel lines and hoses need to be cleaned.
Blown cylinder head gasket - Install a new gasket.
Piston rings are worn or defective - Piston rings need to be replaced.

Engine overheats

Insufficient coolant - Fill the cooling system and check components for leaks or other faults.
Engine oil level low - Fill up the engine oil.
Dirty radiator core or defective radiator cap - Change cap or clean radiator.
Fan belt is loose or defective - The fan belt needs to be replaced.
Engine overloaded - Load reducing required.

Low oil pressure

Engine oil insufficient - Add oil as required.
Dirty oil filter element - Clean or replace engine oil filter element.
Oil grade or viscosity is wrong - Fill up with the correct oil viscosity.
Incorrect oil clearance in crankshaft bearing - Bearing replacement required.
Oil pump is damaged - Check and replace if necessary.

Abnormal engine noise or knocking

Lack of engine oil - Check oil level and add oil as required.
Low coolant temperature - Warm up the engine.
Incorrect adjustment of fuel injection pump timing - Set it up as required.
Incorrect low idle setting - Correct the settings.
Dirty or defective injectors - Clean fuel injectors or change it.
Faulty or misaligned connecting rod - Align or change connecting rod.
Pistons are worn or broken - Have pistons replaced.

Drive System Troubleshooting

Drive system does not work in either direction

Hydraulic oil level is low - Checking hydraulic oil level and add if necessary.
Drive chain fault - Inspect drive chain and replace defective parts.
Defective input drive shaft - Drive shaft need to be replaced or repair.
Defective or worn relief valve - Service or change relief valve.
Hydraulic filter or suction line is plugged - Replace hydraulic filter or clean suction line.
Worn or damaged foot or hand controls - Change or repair.
Defective drive pump or motor - Replace or repair faulty component.

Low power

Hydraulic oil filter is clogged - Replace or service hydraulic filter.
Relief valve is defective or open - Close or replace relief valve.
Transmission components are defective or worn - Inspect and change faulty parts.
Defective input drive shaft - Repair or install a new drive shaft.
Hydraulic system is leaking air - Air bleeding is required.

Overheated drive system

Insufficient hydraulic oil - Need to add oil.
Hydraulic fluid filter is plugged - Replace or service hydraulic filter.
Relief valve is damaged - Repair or replace.
Drive pump or hydraulic motor malfunction - Inspect and replace as necessary.
Plugged hydraulic oil cooler - Clean cooling fins as required.
Drive system is overloaded - Reduce loading.

Drive system makes excessive noise

Oil viscosity is wrong - Use correct oil viscosity.
Air in hydraulic system - Bleed hydraulic system.
Defective drive pump or hydraulic motor - Repair or replace faulty component.
Defective or worn mechanical parts of drive system - Check the parts and change if required.

Hydraulics Troubleshooting

Hydraulic system overheating

Incorrect hydraulic pressure setting - Set pressure correctly.
Main relief valve is damaged or adjusted improperly - Adjust or change relief valve.
Hydraulic fluid contamination - Change hydraulic fluid.
Hydraulic oil level is low - Fill the hydraulic system with oil.
Hydraulic pump is defective - Install new pump or repair it.

Lift arm won't raise or lower

Lift controls are defective - Change or repair.
Hydraulic pump not working - Repair or install new hydraulic pump.
Hydraulic control valve is defective - Change or repair hydraulic valve.
Hydraulic cylinder is faulty - Repair or install a new lift cylinder.
Hydraulic fluid is insufficient - Checking hydraulic fluid level and add if necessary.

Bucket tilt does not work

Faulty bucket tilt controls - Inspect and repair if necessary.
Hydraulic pump not working - Repair or change pump if required.
Hydraulic control valve is defective - Replace or repair the valve.
Hydraulic bucket cylinder is broken - Install a new cylinder or repair it.
Insufficient hydraulic oil - Checking hydraulic oil level and add if necessary.

Slow boom or bucket action

Hydraulic pump is worn - Flow-rate pump and change pump if necessary.
Hydraulic cylinder oil leakage - Replace cylinder piston seals.
Insufficient hydraulic fluid - Fill up the hydraulic fluid.
Hydraulic control valve is faulty or out of adjustment - Set properly or repair.
Low hydraulic pressure - Correct setting is required.

Bucket or boom movements are jerky

Air leaks in hydraulic system - Bleed hydraulic system.
Hydraulic oil filter is clogged - Clean or install new filter.
Hydraulic oil is dirty - Change hydraulic oil.
Cylinder tube or rod is scored - Change worn component.

Hydraulic pump is excessively noisy

Leaking hydraulic system or insufficient oil level - Add hydraulic oil or correct system leaks.
Clogged hydraulic filter - Service or replace hydraulic filter.
Plugged suction line - Need to clean the suction line.
Air in hydraulic pump - Remove air from hydraulics.
Damaged pump components - Rebuild or change hydraulic pump.

Electrical Troubleshooting

Battery cannot be charged

Corroded or loose electrical wire connections - Tighten or clean electrical wiring connections.
Defective battery terminal connectors - Terminal connectors need to be changed.
Battery failing - Battery change required.
Loose or defective belt - Adjust belt tension or install a new belt.

Starter turning slow

Low battery power - Battery is drained, charge it.
Battery is draining quickly - Battery needs service or replacement.
Terminals are faulty or battery cables are disconnected - Check wiring connections or clean terminals.

Starter motor won't turn

Battery is discharged or worn - Battery needs to be recharged or replaced.
Disconnected or incorrectly connected wires - Inspect battery wires and connect correctly.
Low battery voltage - Charge the battery.
Starter motor is damaged - Starter should be changed.