Power steering makes a driver's job a lot easier and today nearly all vehicles have this feature. The system uses power from the engine to operate a small hydraulic pump, which in turn provides assistance to the driver when the steering wheel is turned in one direction or the other. Like all mechanical components, however, the pump can develop problems. By learning to recognise the signs of a bad power steering pump drivers can identify and fix problems before they become serious.
When problems develop in the power steering pump, the pump will usually not deliver the pressure required to assist the driver in turning the steering wheel. The driver will notice a marked increase in the effort needed to turn the wheel.
Most steering pump problems will be accompanied by loud noise. Depending on the nature of the problem, the noise might be a loud clicking or rattling, caused by a broken or defective pump vane. Or it might be a loud whine or moan, possibly indicating problems with a pump bearing or the input shaft. A loud growling noise can indicate a blockage inside the pump and a continuous loud swishing is often caused by a low power steering fluid level. Any unusual noise is the sign of a problem that should be addressed as soon as possible. Be sure to open the vehicle bonnet and verify that the noise is coming from the power steering pump and not another engine component.
Steering Wheel Does Not Return to Center
If the steering wheel does not easily return to the centre position after turning the vehicle it can signify problems with the power steering pump. The likely culprit is a problem with the input shaft bearing.
If there is fluid leaking out of the power steering pump then a seal or gasket has failed or the pump casing has cracked. Be sure the fluid is not simply a result of an overflow from the fluid reservoir caused by overfilling.