Caterpillar 252B3 Skid Steer Troubleshooting

The Caterpillar 252B3 skid steer loader driveline system components: a 207.5 cu.in (3.4L) Cat C3.4 DIT four-cylinder turbocharged diesel engine with a rated power of 71 hp (53 kW), and 2-speed hydrostatic transmission. The hydraulic system has a pump with a rated capacity of 20.3 gal/min (77 l/min). The system relief pressure is 3335 psi (230 bar). The Cat 252B3 is equipped with radial-lift loader boom, 100HS continuous roller chains, and 12x16.5 tires. The skid steer loader has a boom lifting force of 5063 lbs (2296 kg) and bucket breakout force of 5508 lbs (2498 kg). The rated operating capacity is 2650 lbs (1202 kg), and tipping load is 5300 lbs (2404 kg).

Engine Troubleshooting

Engine hard to start or will not start

Air in the fuel pipes - Bleed the fuel pipes.
Dirty fuel filter - Clean the filter or install new filter element.
Faulty or dirty injection nozzles - Check injection nozzles and replace if required.
Dirt or water in fuel system - Drain water or flush dirt from the system.
Valve clearance is out of adjustment - Need to adjust valve clearance.
Fuel injection pump is not operating properly - Rebuild or change fuel pump.

Engine starts but then stops

Air cleaner is dirty - Service or replace air cleaner.
Fuel filter plugging - Change the filter element.
Fuel injection pump has loose connections - Tighten the connections.
Clogged or defective injectors - Replace fuel injectors.
Fuel injection pump malfunctioning - Rebuild or replace pump.

Engine stops unexpectedly during operation

Coolant temperature is low - Warm up engine as required.
Fuel filter element is clogged - Change filter element.
Air in the fuel lines - Bleed the fuel lines.
Fuel injection nozzles are dirty or defective - If necessary, replace with a new nozzle.
Fuel injection pump timing is not adjusted - Adjust as recommended.

Engine stops when idling

Incorrect low idle speed adjustment - Test and adjust.
Damaged fuel injection pump - Replacement or repair required.
Defective fuel injectors - Change or clean fuel injectors.
Excessive valve clearance - Adjust to proper valve clearance.

Lack of engine power

Plugged air cleaner - Clean or change.
Clogged injection nozzle - Check injection nozzles and replace if required.
Fuel injection pressure is wrong - Check the fuel injection pressure and adjust if necessary.
Valve clearance is wrong - Adjust valve clearance according to specifications.
Low idle speed setting is incorrect - Normalize low idle speed.
Fuel lines or hoses are clogged - Clean fuel lines and hoses.
Blown cylinder head gasket - Gasket should be replaced.
Worn or damaged piston rings - Install new piston rings.

Engine overheats

Coolant level is low - Fill the cooling system and check components for leaks or other faults.
Engine oil insufficient - Check and refill engine oil.
Dirty radiator core or faulty radiator cap - Clean radiator or install new cap.
Excessive wear of the fan belt - Replace the fan belt.
Engine overload - Load reducing is recommended.

Oil pressure is low

Insufficient engine oil - Checking oil level and add if necessary.
Oil filter element clogging - Change or clean engine oil filter element.
Different type of engine oil - Use the specified type of engine oil.
Crankshaft bearing has incorrect oil clearance - Bearing replacement required.
Oil pump is worn or damaged - Repair or change.

Engine noise or knocking

Engine oil insufficient - Add oil to the engine crankcase.
Engine is not preheated - Warm up the engine.
Improper fuel injection timing - Use the correct fuel injection pump timing adjustment.
Wrong adjustment of low idle speed - Normalize low idle speed.
Damaged or clogged injectors - Clean fuel injectors or change it.
Connecting rod is defective or misaligned - Align or change connecting rod.
Pistons are broken or worn - Have pistons replaced.

Drive System Troubleshooting

Machine does not move forward or backward

Insufficient hydraulic fluid - Checking hydraulic fluid level and add if necessary.
Drive chain malfunction - Inspect drive chain and replace defective parts.
Input drive shaft is not working properly - Repair or replace drive shaft.
Defective relief valve - Repair or replace.
Clogged hydraulic filter or suction line - Clean suction line or replace hydraulic filter.
Hand or foot controls failure - Inspect and repair if necessary.
Drive pump or motor malfunction - Repair or change faulty component.

Loss of power

Hydraulic oil filter is plugged - Check, clean, or change as necessary.
Faulty or opened relief valve - Close or replace relief valve.
Transmission components are worn or defective - Check and change defective components.
Input drive shaft is stuck - Repair or install a new drive shaft.
Air in the hydraulic system - Bleed air from system.

Overheated drive system

Hydraulic fluid is insufficient - Checking hydraulic fluid level and add if necessary.
Clogged hydraulic fluid filter - Replace or clean hydraulic filter.
Relief valve is not working correctly - Repair or change.
Defective drive pump or hydraulic motor - Repair or change faulty component.
Hydraulic oil cooler is plugged - Cooling fins should be cleaned.
Drive system overloaded continuously - Reduce loading.

Drive system is noisy

Wrong oil viscosity - Use proper oil viscosity.
Air in hydraulic system - Need to bleed air.
Hydraulic motor or drive pump is worn - Change or repair faulty component.
Defective or worn mechanical parts of drive system - Check drive system and change faulty parts.

Hydraulics Troubleshooting

Hydraulic system overheated

Hydraulic pressure is not adjusted correctly - Adjust pressure correctly.
Faulty or improperly adjusted main relief valve - Set up or change the relief valve.
Hydraulic fluid is dirty - Change hydraulic fluid.
Hydraulic oil level is low - Add oil to the hydraulic system.
Defective hydraulic pump - Repair or change pump if required.

Lift arm cannot be raised or lowered

Lift controls are defective - Replace or repair.
Hydraulic pump malfunction - Repair or change pump if required.
Faulty hydraulic control valve - Install a new hydraulic valve or repair it.
Damaged hydraulic cylinder - Repair or install a new lift cylinder.
Insufficient hydraulic fluid - Checking hydraulic fluid level and add if necessary.

Bucket does not tilt

Bucket controls failure - Repair or change.
Hydraulic pump is broken - Repair or replace pump if necessary.
Faulty hydraulic control valve - Repair or change hydraulic valve.
Bucket cylinder is faulty - Repair or change cylinder.
Insufficient hydraulic fluid - Fill up the hydraulic fluid.

Bucket or lift arm is moving slowly

Hydraulic pump is defective - Check pump performance and change it if necessary.
Hydraulic cylinder leaking - Replace cylinder piston seals.
Hydraulic oil is insufficient - Checking hydraulic oil level and add if necessary.
Hydraulic control valve is unadjusted or worn - Repair or set properly.
Hydraulic pressure has dropped - Adjust pressure correctly.

Lift arm or bucket is working jerkily

Air in the hydraulic system - Air bleeding is required.
Hydraulic oil filter element is clogged - Change or clean oil filter.
Hydraulic oil is dirty - Fill up with fresh hydraulic oil.
Cylinder rod or tube is scratched - Replace damaged component.

Hydraulic pump is noisy

Low oil level or hydraulic leaks - Repair hydraulic leaks or add oil as required.
Hydraulic filter clogging - Change or clean oil filter.
Dirty suction line - Service the suction line.
Pump sucks air - Air bleeding is required.
Pump components are damaged - Change or rebuild pump.

Electrical Troubleshooting

Battery does not charge

Loose or corroded wire connections - Tighten or clean electrical wiring connections.
Battery terminal clamps are faulty - Terminal clamps need to be replaced.
Battery is defective - Battery change required.
Loose or defective belt - Adjust belt tension or change the belt.

Starter turning slow

Battery voltage is low - Low battery charging, charge as required.
Battery won’t hold charge - Service or replace the battery.
Disconnected wiring or bad battery terminals - Check cables and service or change terminals.

Starter does not work

Battery is low or faulty - Charge or change the battery.
Wiring is improperly connected or disconnected - Check wiring and connect properly.
Low battery output voltage - Low battery charging, charge as required.
Defective starter motor - Change or repair starter.