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Home / Wheel Loaders / Case Wheel Loaders / Case 621G |
Case 621G Troubleshooting
The
Case 621G wheel loader is powered by 409 cu.in (6.7L) FPT F4H FE613W
six-cylinder direct injection turbocharged liquid-cooled diesel engine with a
rated power of 138 hp (103 kW) at 2000 rpm. The Case 621G is equipped with a 4x3
autoshift transmission, power steering system, hydraulic wet disc brakes, and
20.5R25 standard tires. The hydraulic system has a pump with fluid flow rate of
42.5 gpm (171 lpm). The hydraulic pressure is 3625 psi (250 bar). The wheel
loader has a rated operating capacity of 12305 lbs (5580 kg) and tipping load of
24610 lbs (11160 kg). The max lift height is 150.9" (3835 mm) to hinge pin, and
breakout force is 27280 lbs (12375 kg).
Engine Troubleshooting |
Engine starts hard or doesn't start
Air trapped in fuel system - Bleed air.
Fuel filter plugging - Change the filter element.
Fuel injection nozzles are clogged or faulty - Install a new kit of correctly balanced nozzles.
Water in the fuel system - Change fuel and repair fuel system.
Excessive valve clearance - Adjust valve clearance according to specifications.
Fuel injection pump malfunction - Rebuild or install a new injection pump.
Diesel starts but stalls suddenly
Dirty air cleaner - Clean or replace element.
Clogged fuel filter - Install new filter element.
Poor fuel injection pump tightness - Look for any leaks of fuel pump, tighten it fast.
Dirty or defective injectors - Change or clean fuel injectors.
Fuel injection pump is not operating properly - Install a new fuel pump or repair.
Engine stops running suddenly
Coolant temperature is low - Warm up the engine.
Fuel filter element clogging - Change filter element.
Air in the fuel lines - Bleed the fuel lines.
Damaged or dirty injection nozzles - Clean or replace injection nozzles.
Timing of fuel injection pump is incorrect - Use the correct fuel injection pump timing adjustment.
Engine stalls at idle
Too low idle RPM - Correct low idle settings.
Fuel injection pump damage - Install a new pump or rebuild.
Defective fuel injectors - Change or clean fuel injectors.
Valve clearance is not correct - Adjustment procedure required.
Diesel power loss
Plugged air filter - Service or replace the air filter.
Defective injection nozzle - Install a new kit of correctly balanced nozzles.
Incorrect fuel injection pressure - Adjust to proper pressure.
Valve clearance is wrong - Check and adjust.
Wrong adjustment of low idle speed - Correct the settings.
Fuel lines or hoses are clogged - Fuel lines and hoses need to be cleaned.
Cylinder head gasket defective - Cylinder-head gasket replacement required.
Leaking or damaged piston rings - Replace piston rings.
Engine overheating
Low coolant level - The cooling system needs to be refilled and checked for faults.
Low engine oil level - Fill up the oil to required level.
Dirty radiator fins or defective radiator cap - Install new cap or clean radiator.
Fan belt slipping or worn - Fan belt must be replaced.
Engine overloaded - Load reducing is recommended.
Insufficient oil pressure
Not enough oil in the engine - Need to add oil.
Oil filter is dirty - Clean or change engine oil filter.
Different type of engine oil - Use proper viscosity oil.
Incorrect oil clearance in crankshaft bearing - Replace bearings.
Oil pump is damaged - Replace as required.
Engine noises or knocks
Engine oil insufficient - Fill the crankcase with engine oil.
Engine is not preheated - Warm up engine as required.
Fuel injection pump timing is not adjusted - Set it up as required.
Improperly adjusted low idle speed - Test and adjust.
Fuel injector fault - Clean or replace fuel injectors.
Connecting rod misalignment or failure - Align or change connecting rod.
Scored or worn pistons - Install new pistons.
Transmission Troubleshooting |
Insufficient transmission fluid pressure
Lack of transmission oil supply - Need to add transmission oil.
Transmission oil filter is clogged (if fitted) - Service or replace the transmission oil filter.
Stuck relief valve - Install a new valve.
Excessive transmission noise
Transmission oil level is low - Check and refill the transmission oil.
Transmission fluid is contaminated - Change the fluid.
Backlash is incorrect or gears are damaged - Install new gears and set backlash correctly.
Bearings are damaged or worn - Change faulty bearings.
Worn or bent gear shift forks - Shift forks need to be replaced.
Shaft splines are worn or stuck - Replace defective shaft.
Hard shifting
Rusty or worn gear shift linkage - Change or lubricate shift linkage.
Damaged or worn gear shift forks - Replace defective shift forks.
Worn out parts of the gearshift mechanism - Replace worn parts.
Improperly adjusted or worn clutch - Clutch needs to be adjusted or changed.
Transmission oil leaking
High transmission fluid level - Drain the excess fluid.
Seals or gaskets are broken - Install new seal or gaskets.
Hydraulics Troubleshooting |
Hydraulic system has overheating
Hydraulic pressure is not adjusted correctly - Adjust pressure as required.
Main relief valve is faulty or misadjusted - Adjust the valve or replace if necessary.
Hydraulic oil contamination - Change hydraulic oil.
Hydraulic oil level is low - Fill the hydraulic system with oil.
Hydraulic pump is worn - Repair or replace pump if necessary.
Lift arm can't drop or lift
Lift controls are faulty - Repair or change.
Hydraulic pump is broken - Repair or install new hydraulic pump.
Damaged hydraulic control valve - Repair or replace hydraulic valve.
Hydraulic cylinder malfunction - Repair or change hydraulic cylinder.
Insufficient hydraulic oil - Need to add oil.
Bucket does not tilt
Bucket tilt controls malfunction - Replace or repair.
Hydraulic pump failure - Repair or replace pump if necessary.
Hydraulic control valve is faulty - Repair or change hydraulic valve.
Bucket cylinder is faulty - Replace or repair cylinder.
Low hydraulic oil level - Fill the system to proper hydraulic oil level.
Slow boom or bucket operation
Hydraulic pump is worn - Test pump performance and replace pump if necessary.
Leaking hydraulic cylinder - Change cylinder piston seals.
Hydraulic fluid is insufficient - Checking hydraulic fluid level and add if necessary.
Damaged or incorrect adjusted hydraulic control valve - Repair or set properly.
Hydraulic system loosing pressure - Hydraulic pressure must be set correctly.
Bucket or boom is moving jerkily
Hydraulic system is leaking air - Bleed air from system.
Plugged hydraulic oil filter - Clean or replace the filter.
Contaminated hydraulic fluid - The fluid must be changed.
Scratched cylinder rod or tube - Replace worn component.
Hydraulic pump is noisy
Hydraulic leaks or lack of oil - Remedy hydraulic leakage or refill oil as necessary.
Hydraulic filter is clogged - Service or change hydraulic filter.
Dirty suction line - Service the suction line.
Air trapped in hydraulic pump - Air bleeding is required.
Faulty pump components - Install new hydraulic pump or rebuild it.
Electrical Troubleshooting |
Battery cannot be charged
Electrical cable connections are corroded or loose - Tighten or clean electrical wiring connections.
Battery terminal connectors are defective - Replace terminal connectors.
Faulty cell in battery - Install a new battery.
Belt is loose or defective - Replace belt or adjust belt tension.
Starter turning slow
Battery power is low - Charge the battery.
Battery runs out quickly - Battery needs to be serviced or replaced.
Disconnected battery cables or bad terminals - Connect cables properly or replace terminals.
Starter does not work
Battery is drained or defective - Charge or change the battery.
Wire harness is disconnected or incorrectly connected - Check wire harness and connect as required.
Low battery capacity - Battery is drained, charge it.
Starter motor is damaged - Repair or install a new starter.
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WHEEL LOADERS SPECIFICATIONS |
Bobcat
Caterpillar
Case
Doosan
John Deere
Kubota