____________________________________________________________________________________

Home / Wheel Loaders / JCB Wheel Loaders / JCB 403

JCB 403 Troubleshooting

The JCB 403 wheel loader is powered by 91.4 cu.in (1.5L) Kubota V1505 4-cylinder indirect injection water-cooled diesel engine with a rated power of 25 hp (19 kW) at 2200 rpm. The JCB 403 is equipped with a two-speed hydrostatic transmission, hydraulic power steering system, hydraulic wet disc brakes, and 31x15.50-15 standard tires. The hydraulic system has a gear pump with fluid flow rate of 11.4 gpm (43.2 lpm). The hydraulic pressure is 2610 psi (180 bar). The wheel loader has a rated operating capacity of 1778 lbs (808 kg) and tipping load of 3555 lbs (1616 kg). The maximum lift height is 113.4" (2880 mm) to hinge pin, and breakout force is 3585 lbs (1630 kg).

Engine Troubleshooting

Engine difficult to start or won't start
Air trapped in fuel system - Bleed air.
Clogged fuel filter - Service or replace the filter.
Defective or clogged injection nozzle - Change fuel injection nozzles.
Dirt or water in fuel system - Drain water or flush dirt from the system.
Valve out of adjustment - Check and adjust.
Fuel injection pump is broken - Rebuild or replace pump.

Engine starts and stalls suddenly
Dirty air cleaner - Clean or replace element.
Fuel filter plugged - Change or clean the filter element.
Poor fuel injection pump tightness - Look for any leaks of fuel pump, tighten it fast.
Clogged or defective injectors - Clean or replace fuel injectors.
Fuel injection pump is broken - Repair or change injection pump.

Diesel shuts off while driving
Low coolant temperature - Warm up the engine.
Clogged fuel filter - Change filter element.
Air in fuel system - Bleed fuel system.
Clogged injection nozzle - Clean or change injection nozzles.
Fuel injection pump timing is not adjusted - Set the fuel pump timing correctly.

Engine stops at low idle speed
Incorrectly set low idle speed - Test and adjust.
Fuel injection pump is broken - Change pump or rebuild it.
Clogged or defective injectors - Replace fuel injectors.
Improper valve clearance - Adjust valve clearance.

Engine power loss
Plugged air filter - Service or replace the air filter.
Faulty fuel injection nozzles - Clean or replace injection nozzles.
Fuel injection pressure is wrong - Check the fuel injection pressure and adjust if necessary.
The valve clearance is not adjusted - Adjust valve clearance.
Too low idle RPM - Need to adjust idle speed.
Fuel hoses or lines clogging - Fuel hoses and lines must be clean.
Cylinder-head gasket is broken - Gasket should be replaced.
Worn or broken piston rings - Piston rings replacement required.

Engine overheating
Low engine coolant - Fill the cooling system and check components for leaks or other faults.
Engine oil level low - Fill up the engine oil.
Clogged radiator fins or leaking radiator cap - Install new cap or clean radiator.
Fan belt is broken or worn - Change as required.
Diesel engine is overloaded - Reduce engine load.

Oil pressure too low
Low crankcase oil level - Check and refill the oil.
Clogged oil filter - Service or change engine oil filter element.
Incorrect oil viscosity - Drain crankcase and refill with correct oil.
Crankshaft bearing oil clearance is incorrect - Install new bearings.
Oil pump is damaged - Replace as required.

Engine noise or knocking
Engine oil insufficient - Check oil level and add oil as required.
Engine is not fully warmed up - Normalize the temperature by warming up the engine.
Fuel injection pump timing is not adjusted - Adjust fuel injection pump as required.
Improperly adjusted low idle speed - Adjust low idling as recommended.
Fuel injectors are faulty or clogged - Replace fuel injectors.
Connecting rod is misaligned or defective - Connecting rod must be aligned or replaced.
Broken or worn pistons - Install new pistons.

Hydrostatic Transmission Troubleshooting

Hydrostatic transmission is making noise
Transmission fluid is dirty or fluid level is too low - Fill to required level or change the fluid.
Speed control linkage is defective or unadjusted - Adjust or replace linkage.
Relief valve malfunction - Change relief valve.
Excessive transmission load - Reduce loading.
Transmission components are damaged or worn - Check internal transmission parts for damage or wear and replace if required.

Power is insufficient
Lack of transmission fluid - Check and refill the transmission fluid.
Defective relief valve - Replace relief valve as required.
Speed control linkage is worn or unadjusted - Adjust or change linkage.

Transmission fluid overheated
Insufficient transmission oil - Check transmission oil level and add oil as required.
Transmission oil filter element clogging - Clean or replace the transmission filter.
Plugged or defective cooling components - Check all cooling components and change or clean if required.
Transmission overload - Reduce the load is required.

Transmission oil leaking
Damaged gaskets or seals - Replace worn seal or gaskets.
Internal transmission housing pressure is too high - Replace worn components.
Oil drain line is clogged - Clean or change the line.

Hydraulics Troubleshooting

Hydraulic system is overheated
Hydraulic pressure is not correct - Adjust pressure as required.
Main relief valve is defective or unadjusted - Adjust relief valve or change if required.
Hydraulic oil is contaminated - Hydraulic oil change required.
Not enough hydraulic oil in the system - Check oil level and add hydraulic oil as required.
Hydraulic pump is worn - Repair or install new hydraulic pump.

Lift arm cannot be raised or lowered
Lift controls are damaged - Repair or replace.
Defective hydraulic pump - Repair or change pump if required.
Hydraulic control valve is faulty - Install a new hydraulic valve or repair it.
Hydraulic cylinder is broken - Repair or change hydraulic cylinder.
Low hydraulic fluid level - Fill the system to proper hydraulic fluid level.

Bucket does not function
Damaged bucket controls - Check and repair as required.
Defective hydraulic pump - Install new pump or repair it.
Damaged hydraulic control valve - Replace or repair the valve.
Bucket cylinder failure - Change or repair cylinder.
Hydraulic fluid is insufficient - Fill the system to proper hydraulic fluid level.

Boom or bucket runs slowly
Worn hydraulic oil pump - Check pump flow and change pump if necessary.
Hydraulic cylinder leaking - Correct leakage by changing the seals.
Hydraulic oil level low - Check and refill the hydraulic oil.
Hydraulic control valve is unadjusted or worn - Repair or adjust properly.
Hydraulic pressure is low - Adjust pressure as required.

Bucket or boom is working jerkily
There is air in the hydraulic system - Bleed hydraulic system.
Clogged hydraulic oil filter element - Replace or clean the filter.
Hydraulic oil is dirty - Hydraulic oil change required.
Cylinder rod or tube is scratched - Replace defective component.

Hydraulic pump is noisy
Hydraulic leaks or low oil level - Correct hydraulic leaks or top up oil as needed.
Plugged hydraulic filter - Service or change hydraulic filter.
Suction line is dirty - Need to service the suction line.
Pump is sucking air - Remove air from hydraulics.
Pump components are worn out - Install new hydraulic pump or rebuild it.

Electrical Troubleshooting

Battery is not charging
Electrical cable connections are corroded or loose - Tighten or clean connections.
Battery terminal clamps are defective - Terminal clamps should be changed.
Battery faulty cell - Battery change required.
Belt is worn or loose - Change belt or adjust belt tension.

Starter motor turns slow
Low battery voltage - Low battery charging, charge as required.
Battery is draining quickly - Service or change the battery.
Disconnected wiring or bad battery terminals - Connect wires correctly or change terminals.

Starter doesn't crank
Battery is discharged or defective - Recharge or replace battery.
Disconnected or incorrectly connected wires - Inspect battery wires and connect correctly.
Low battery output - Battery is drained, recharge it.
Starter motor is damaged - Starter should be replaced.

____________________________________________________________________________________

____________________________________________________________________________________

WHEEL LOADERS SPECIFICATIONS

Caterpillar