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Home / Wheel Loaders / Case Wheel Loaders / Case 721G

Case 721G Troubleshooting

The Case 721G wheel loader is powered by 411 cu.in (6.7L) FPT F4H FE613T 6-cylinder in-line direct injection turbocharged liquid-cooled diesel engine with a rated power of 144 hp (107 kW) at 2000 rpm. The Case 721G is equipped with a four-speed transmission, power steering system, hydraulic multiple wet disc brakes, and 20.5R25 tires. The closed center hydraulic system has two pumps with fluid flow rate of 31.6 gpm (120 lpm) and 22.6 gpm (86 lpm). The wheel loader has a rated operating capacity of 13670 lbs (6205 kg) and tipping load of 27340 lbs (12410 kg). The max lift height is 156.5" (3975 mm) to hinge pin, and breakout force is 33810 lbs (15335 kg).

Engine Troubleshooting

Engine starts hard or will not start
Air in the fuel pipes - Bleed the fuel pipes.
Fuel filter element is dirty - Clean or replace the filter.
Dirty or damaged injection nozzles - Inspect nozzles and replace if necessary.
Water or dirt in fuel system - Drain, flush, and service the system.
Valve clearance is wrong - Check and adjust.
Fuel injection pump is broken - Rebuild or install a new injection pump.

Engine starts but stalls immediately
Plugged air cleaner - Clean or replace air cleaner element.
Fuel filter element is clogged - Clean or replace the filter.
Fuel injection pump leakage - Check the fuel injection pump for leaks and fix it.
Defective or clogged fuel injectors - Change or clean fuel injectors.
Fuel injection pump damage - Rebuild or replace pump.

Engine stalls after running
Coolant temperature is low - Warm up engine as required.
Fuel filter element clogging - Clean the filter or install new filter element.
Air in the fuel pipes - Bleed the fuel pipes.
Clogged or defective injection nozzles - Clean or change injection nozzles.
Incorrect adjustment of fuel injection pump timing - Adjust according to specifications.

Engine stalls at idle
Incorrect low idle setting - Adjust the low idle speed.
Fuel injection pump is not working correctly - Install a new fuel pump or repair.
Clogged or defective injectors - Change or clean fuel injectors.
The valve clearance is incorrect - Check and adjust.

Engine power is insufficient
Air cleaner is clogged - Service or replace air cleaner.
Clogged or defective injection nozzles - Change fuel injection nozzles.
Fuel injection pressure is wrong - Adjust to proper pressure.
Improper valve clearance - Adjust valve clearance.
Wrong adjustment of low idle speed - Adjust as required.
Dirt in the fuel hoses or lines - Clean fuel system lines and hoses.
Defective cylinder head gasket - Install new cylinder head gasket.
Piston rings are leaking or defective - Piston rings need to be replaced.

Engine overheating
Low coolant level - Add coolant and check the components of cooling system.
Engine oil level low - Add oil to the engine crankcase.
Defective radiator cap or clogged radiator fins - Install new cap or clean radiator.
Loose or defective fan belt - Change the fan belt.
Diesel engine overloaded - Reduce engine load.

Oil pressure too low
Lack of oil - Fill crankcase to proper oil level.
Plugged engine oil filter - Replace or clean engine oil filter element.
Improper type of engine oil - Use proper viscosity oil.
Excessive main bearing oil clearance - Bearing needs to be changed.
Oil pump malfunction - Repair or replace.

Engine knocking sound or abnormal noise
Not enough engine oil - Need to add engine oil.
Engine not warmed up - Normalize the temperature by warming up the engine.
Fuel injection pump timing is wrong - Use the correct fuel injection pump timing adjustment.
Incorrectly adjusted low idle speed - Adjust low idling as recommended.
Damaged or clogged injectors - Inspect fuel injectors and change as required.
Connecting rod is worn or not aligned - Need to change or align the connecting rod.
Worn or broken pistons - Pistons need to be replaced.

Transmission Troubleshooting

Insufficient transmission fluid pressure
Transmission oil insufficient - Add oil to the transmission housing.
Plugged transmission oil filter (if equipped) - Service or replace the transmission oil filter.
Relief valve is damaged - Replace relief valve as required.

Transmission is making noise
Low oil level - Need to add transmission oil.
Transmission fluid is contaminated - Change the fluid.
Damaged gears or incorrect backlash - Adjust backlash correctly or replace the gears.
Bearings are cracked or worn - Install new bearings.
Shift forks are bent or worn out - Install new shift forks.
Damaged or worn shaft splines - Shaft need to be changed.

Difficult to shift gears
Gear shift linkage is corroded or worn - Change or lubricate shift linkage.
Shift forks are worn or bent - Change defective shift forks.
Worn parts of the gear shifting mechanism - Change worn parts.
Clutch is out of adjustment or defective - Adjust or install new clutch.

Transmission oil leakage
Transmission oil level is exceeded - Correct the oil volume.
Worn seals or gaskets - Install new components.

Hydraulics Troubleshooting

Hydraulic system is overheated
Hydraulic pressure incorrectly adjusted - Adjust it correctly.
Unadjusted or defective main relief valve - Adjust the valve or replace if necessary.
Hydraulic oil is dirty - The oil must be changed.
Hydraulic oil level is insufficient - Check oil level and add hydraulic oil as required.
Hydraulic pump is faulty - Install new pump or repair it.

Boom cannot be lowered or raised
Lift controls are damaged - Repair or replace.
Damaged hydraulic oil pump - Install new pump or repair it.
Defective hydraulic control valve - Change or repair hydraulic valve.
Hydraulic cylinder malfunction - Change or repair lift cylinder.
Hydraulic oil is insufficient - Check and refill the hydraulic oil.

Bucket won't move
Bucket controls are faulty - Repair or change.
Hydraulic pump not working - Change or repair hydraulic pump if required.
Damaged hydraulic control valve - Replace or repair the valve.
Hydraulic bucket cylinder is broken - Change or repair cylinder.
Hydraulic fluid is insufficient - Fill up the hydraulic fluid.

Boom or bucket moves slowly
Hydraulic pump is defective - Test the pump flow rate and install new pump if required.
Oil leaks from hydraulic cylinder - Cylinder seals need to be replaced.
Insufficient hydraulic fluid - Fill the system to proper hydraulic fluid level.
Hydraulic control valve is defective or set improper - Adjust properly or repair.
Hydraulic pressure has dropped - Correct setting is required.

Lift arm or bucket is moving jerkily
Hydraulic system is leaking air - Bleed air from hydraulic system.
Dirty hydraulic oil filter - Clean or replace the filter.
Hydraulic oil contamination - Hydraulic oil change required.
Scratched cylinder rod or tube - Change damaged component.

Hydraulic pump is noisy
Not enough oil or hydraulic system leaking - Top up hydraulic oil or remedy leakage in system.
Clogged hydraulic filter - Replace or clean the filter.
Dirty suction line - Suction line needs to be cleaned.
Pump sucks air - Remove air from hydraulics.
Pump parts are damaged - Rebuild or change hydraulic pump.

Electrical Troubleshooting

Battery won’t charge
Corroded or loose wire connections - Tighten or clean electrical wiring connections.
Faulty battery terminal clamps - Replace terminal clamps.
Battery bad cell - Battery change required.
Damaged or loose belt - Adjust belt tension or change the belt.

Starter cranks slowly
Battery power is low - Battery is drained, recharge it.
Battery is not holding charge - Service charging system or install new battery.
Disconnected cables or faulty battery terminals - Check wire connections and change or service terminals.

Starter motor won't turn
Battery is low or faulty - Battery needs to be recharged or replaced.
Disconnected or improperly connected wiring harness - Inspect battery wiring harness and connect as required.
Low battery capacity - Charge the battery.
Starter motor is faulty - Starter should be changed.

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WHEEL LOADERS SPECIFICATIONS

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