HANDHOLD GP 3548358 - Caterpillar

Operation Checks
The front wheels must be on a dry, smooth hard surface and the hydraulic oil in the steering system must be warm.Start the machine. In first gear, slowly drive the machine while you turn the steering wheel. Drive the machine until the hydraulic oil temperature is approximately 65°C (150°F).Test the steering system with the engine at high idle. Rotate the steering wheel. Measure the time that is required to turn the front wheels from the full right turn position to the full left turn position and back to the full right turn position. If the time is more than 9.0 seconds, there could be a problem in the steering hydraulic system. If the time is less than 7.0 seconds, there could be a problem in the steering hydraulic system.Failures in the steering system can be at least one of the following items:
Broken oil line or a leak in an oil line connection
Worn hydraulic oil pump
Pressure setting of the backup relief valve
Worn steering metering pump
Pressure setting of steering crossover relief valve
Leaking steering crossover relief valve
Worn steering cylinders
Improperly charged accumulators
Pressure setting of the pressure and flow compensator valvePerformance Checks
Performance checks of the steering system can be used for the following purposes:
Diagnosis of poor performance
Source of oil leakage inside the hydraulic systemProblem: Noisy steering pump
Probable Cause
Air in the steering hydraulic circuit
Loose connection of the oil line on the inlet side of the pump
Low oil level in the steering hydraulic tank
Wrong oil viscosityProblem: Too much force is required to turn the steering wheel.
Probable Cause
Open backup relief valve
Low oil in the steering hydraulic tank
Low oil pressure in the accumulator
Worn pump
Tight end cover on the steering metering pump
Interference of components on steering column with shaft
Improper operation of steering metering pump
Improper operation of steering crossover relief valve
Cold oil
Restriction in the steering linkage
The solenoid that is located on the steering solenoid and relief valve is bad. Problem: The machine does not turn when the steering wheel is turned.
Probable Cause
Air in system
Malfunction in steering crossover relief valve
Lack of oil in steering metering pump
Worn steering metering pump
Disengaged steering column shaft from steering metering pumpProblem: Erratic steering
Probable Cause
Air in system
Worn steering linkage
Worn cylinder piston
Loose cylinder piston
Malfunction of steering crossover relief valve
Incorrect timing of steering metering pumpFor proper assembly of the steering metering pump, refer to System Operation, "Metering Pump (Steering)".Problem: The machine turns too slowly in both directions.
Probable Cause
Not enough oil flow from the steering pump
Malfunction of steering crossover relief valve
Failed accumulatorProblem: The machine turns too slowly in one direction.
Probable Cause
Restriction in steering metering pump
Malfunction of steering crossover relief valveProblem: The steering wheel does not return to the center position correctly.
Probable Cause
Tight cover on steering metering pump
Interference of components on steering column with shaft
Restriction between spool and sleeve in steering metering pump
Damaged centering springs in steering metering pump
Broken centering springs in steering metering pumpProblem: Hot oil temperature
Probable Cause
The steering pump does not destroke.
Wrong oil viscosity
Air in the oil
Low oil in the steering hydraulic tank
Low pressure setting on the backup relief valve
Restriction in the line circuit
Oil leakage by the