Caterpillar 257B3 Track Loader Troubleshooting

The Caterpillar 257B3 multi-terrain loader is powered by 207.5 cu.in (3.4L) Cat C3.4 DIT 4-cylinder turbocharged diesel engine with a rated power of 100 hp (74.6 kW). The Cat 257B3 is equipped with a two-speed hydrostatic transmission, vertical-lift loader boom, single level suspension undercarriage, and 12.6" (320 mm) durable rubber tracks. The hydraulic system has a pump with fluid flow rate of 22 gpm (83 lpm) or 31 gpm (117 lpm). The hydraulic pressure is 3335psi (230 bar). The loader has a rated operating capacity of 1870 lbs (848 kg) and tipping load of 5350 lbs (2426 kg). The lift height is 120.9" (3070 mm) to hinge pin, and dump height is 91" (2310 mm).

Engine Troubleshooting

Engine difficult to start or won't start

Air in fuel system - Bleed fuel system.
Clogged fuel filter - Change filter element.
Faulty or dirty injection nozzles - Clean or change injection nozzles.
Water in the fuel system - Change fuel and repair fuel system.
Improper valve clearance - Check and adjust.
Fuel injection pump is defective - Install a new pump or rebuild.

Diesel starts and suddenly stops

Air filter is dirty - Install new air filter element.
Fuel filter element clogging - Change or clean the filter element.
Fuel injection pump leakage - Check the fuel injection pump for leaks and fix it.
Fuel injectors are faulty or clogged - Replace fuel injectors.
Faulty fuel injection pump - Repair or replace injection pump.

Engine shuts off while running

Low coolant temperature - Warm up the engine as required.
Clogged fuel filter - Clean or change the filter.
Air trapped in fuel system - Bleed air.
Fuel injection nozzles are damaged or dirty - Install a new kit of correctly balanced nozzles.
Timing of fuel injection pump is incorrect - Check the fuel injection pump timing adjustment.

Engine stalls at low idle speed

Incorrectly adjusted low idle speed - Test and adjust.
Fuel injection pump damage - Rebuild or change fuel pump.
Damaged or clogged injectors - Replace fuel injectors.
The valve clearance is not adjusted - Check and adjust.

Lack of engine power

Clogged air filter - Service or replace the air filter.
Defective or clogged injection nozzle - Service or change injection nozzles.
Incorrect fuel injection pressure - Test fuel injection pressure and adjust it correctly.
Improper valve clearance - Adjustment procedure required.
Incorrect low idle speed adjustment - Adjustment required.
Fuel lines or hoses are clogged - Service fuel lines and hoses.
Leaking cylinder head gasket - Install a new gasket.
Piston rings are worn or damaged - Piston rings need to be replaced.

Engine overheated

Insufficient coolant - Add coolant and check the components of cooling system.
Engine oil level is insufficient - Checking oil level and add if necessary.
Dirty radiator fins or defective radiator cap - Clean radiator or change cap.
Loose or defective fan belt - Replace as required.
Engine is under excessive load - Reduce load on the engine.

Low oil pressure

Oil level is insufficient - Add oil as required.
Oil filter clogged - Replace or service engine oil filter.
Incorrect oil viscosity - Use the specified type of engine oil.
Crankshaft bearing has incorrect oil clearance - Change bearings.
Oil pump malfunction - Repair or replace.

Engine noise or knocking

Engine oil level is insufficient - Fill the crankcase with engine oil.
Engine has not warmed up to recommended temperature - Warm up engine as required.
Improper fuel injection timing - Adjust fuel injection pump as required.
Low idle speed adjustment is incorrect - Correct the settings.
Fuel injector fault - Replace fuel injectors.
Connecting rod is misaligned or defective - Connecting rod needs to be aligned or changed.
Worn or broken pistons - Have pistons replaced.

Drive System Troubleshooting

Machine is not moving forward or backward

Hydraulic fluid level low - Check and refill the hydraulic fluid.
Jammed or damaged undercarriage tracks - Repair or remedy jamming.
Relief valve is not working correctly - Change or repair relief valve.
Hydraulic filter or suction line is clogged - Check, clean, or change if necessary.
Defective foot or hand controls - Replace or repair.
Drive motor or pump failure - Inspect and change as required.

Machine won't move straight or moves jerky

Damaged or jammed undercarriage tracks - Repair or remove jamming.
Sagging or faulty tracks - Adjust track sag with tensioning or replace tracks.
Foreign objects, debris, or dirt stuck in track frame - Remove debris or foreign objects and clean track frame.

Reduced power

Clogged hydraulic oil filter - Change or clean hydraulic filter.
Faulty or opened relief valve - Replace or close relief valve.
Worn or defective transmission parts - Check and replace faulty components.
Worn input drive shaft - Replace drive shaft.
Hydraulic system is leaking air - Need to bleed air.

Drive system is overheated

Hydraulic fluid level low - Checking hydraulic fluid level and add if necessary.
Hydraulic fluid filter is clogged - Change or service hydraulic filter.
Relief valve is defective - Repair or replace.
Drive pump or hydraulic motor malfunction - Inspect and replace as necessary.
Hydraulic oil cooler is plugged - Clean cooling fins as required.
Drive system overloaded continuously - Reduce drive system load.

Drive system is excessively noisy

Improper oil viscosity - Use correct oil viscosity.
There is air in the hydraulic system - Bleed hydraulic system.
Hydraulic motor or drive pump is defective - Repair or change faulty component.
Mechanical components of drive system are worn or damaged - Check drive system and change faulty components.

Hydraulics Troubleshooting

Hydraulic system has overheating

Hydraulic pressure incorrectly adjusted - Adjust pressure correctly.
Main relief valve improper adjustment or failure - Adjust the valve or replace if necessary.
Dirty hydraulic oil - Fill up with fresh hydraulic oil.
Hydraulic oil level is insufficient - Fill up the hydraulic oil.
Worn hydraulic oil pump - Repair or replace pump if necessary.

Lift arm fails to drop or lift

Defective lift controls - Change or repair.
Hydraulic pump is broken - Change or repair hydraulic pump if required.
Damaged hydraulic control valve - Install a new hydraulic valve or repair it.
Damaged hydraulic cylinder - Install a new boom cylinder or repair it.
Low hydraulic fluid level - Fill the system to proper hydraulic fluid level.

Bucket is not working

Bucket controls are faulty - Replace or repair.
Damaged hydraulic oil pump - Replace or repair pump if necessary.
Hydraulic control valve malfunction - Repair or replace hydraulic valve.
Hydraulic bucket cylinder is defective - Install a new cylinder or repair it.
Hydraulic oil level low - Fill the system to proper hydraulic oil level.

Bucket or lift arm is moving slowly

Defective hydraulic pump - Test the pump flow rate and change pump if required.
Leaking hydraulic cylinder - Repair leak by replacing the seals.
Hydraulic fluid is insufficient - Fill up the hydraulic fluid.
Hydraulic control valve is not set properly or defective - Set properly or repair.
Low hydraulic pressure - Hydraulic pressure must be set correctly.

Bucket or boom is moving jerkily

Air trapped in hydraulic system - Bleed air from hydraulic system.
Dirty hydraulic oil filter - Clean or install new filter.
Contaminated hydraulic oil - Fill up with fresh hydraulic oil.
Cylinder rod or tube is scuffed - Change damaged component.

Excessive hydraulic pump noise

Low oil level or hydraulic leaks - Add hydraulic oil or correct system leaks.
Plugged hydraulic filter - Clean or install new filter.
Dirty suction line - Suction line must be serviced.
Pump sucks air - Air bleeding is required.
Faulty pump parts - Replace or rebuild the pump.

Electrical Troubleshooting

Battery does not charge

Electrical cable connections are corroded or loose - Clean or tighten wiring connections.
Defective electrical terminal connectors - Change terminal connectors.
Faulty cell in battery - Install a new battery.
Worn or loose belt - Belt needs to be adjusted or changed.

Starter motor cranks slow

Low battery power - Battery is drained, charge it.
Battery discharges quickly - Service battery or replace it.
Disconnected cables or faulty battery terminals - Connect cables correctly or replace terminals.

Starter will not work

Battery is drained or defective - Charge or change the battery.
Wiring is improperly connected or disconnected - Check wiring and connect properly.
Low battery capacity - Low battery charging, charge as required.
Defective starter motor - Starter needs to be replaced.