If you can hear a strange, almost melodic whine when you turn the steering wheel in your car, you may be wondering what on earth is going on. The tune appears to change as you move the wheel from one point to another, and you may, in certain circumstances, notice that it seems more challenging to do this than usual. In this case, the culprit may be your power steering pump, so what do you need to know about this issue?

Power Steering Systems

While some vehicles are now fitted with a fully electric steering assist system, many will still feature the conventional hydraulic approach. Special fluid runs through lines that connect the steering column with the rack, and this fluid is pushed under pressure through a sequence of valves and gears to make it a lot easier for the horizontal rack to move. This means that you need to exert far less pressure on the steering wheel to move the road wheels against the friction of the asphalt beneath.

The steering pump helps to pressurise and push the fluid at just the right moment and apply torque to the steering wheel. It's typically linked to the engine via a serpentine belt, enabling the internal impeller to rotate.

Bearing Difficulties

Certainly, you can expect the power steering pump to run without any issue for long periods. However, the bearing that supports the main shaft can begin to deteriorate. This shaft runs in between the impeller and the external pulley, and if the bearing does start to fail, the shaft will oscillate. As this happens, it will begin to vibrate, and this vibration will change according to the amount of pressure you place on the steering wheel. Now you can see why the sound changes as you turn the wheel and as you are trying to pump hydraulic fluid through the mechanism.

Additional Signs

You may also notice tell-tale evidence towards the base of the steering column, where you will typically find the pump. When the bearing begins to fail, it may also affect the seals that keep the fluid within the system. You may see evidence of a leak in this area or on the ground immediately beneath.

Fixing the Issue

Typically, it is impossible to change the bearing in this situation, and you will need to replace the entire pump. Always make sure that you fit the highest quality component you can find and one that is recommended for your particular make and model.

Look at the Belt As Well

When you replace it, take a good look at the condition of the serpentine belt at the same time. If any of the teeth appear to be damaged, or the best itself has taken on a glazed appearance, you may need to replace this too.