Why Does The Steering Wheel Vibrate When You Brake?

Posted on: 23 February 2015

If you suddenly notice that your steering wheel is vibrating wildly when you brake, you need to investigate the cause. This can be really disconcerting, to say nothing of the danger the condition poses when you're trying to remain in control of your vehicle. What is the cause and what can you do about it?

Does It Happen Only When You Brake?

Firstly, make sure that the condition manifests only when you brake. There could be a number of reasons for vibrations in your steering column that have nothing to do with the brakes. For example, if your CV joints (which connect the suspension uprights to the steering) are worn, significant vibrations can arise. Likewise, an engine mounting could be broken. If, however, the shaking happens only when you brake, then it is more likely associated with the brake discs themselves.

Why Are Brake Discs Vulnerable?

Metal brake discs are finely engineered pieces of equipment. They operate under some intense heat. When you apply the brakes, friction pads "grab" the disc, causing it to slow down, which in turn brings the car to a stop.

What Goes Wrong?

With age, brake discs begin to deteriorate by becoming thinner in places or by warping, so they are out of shape. If these conditions apply then whenever the brake pads come into contact with the out of balance disc, those imperfections will be transmitted all the way to your steering column.

Alternatively, your driving habits could be contributing to the problem. If you tend to be the last of the late brakers, then you are transferring a great deal of heat to the discs. This can cause them to overheat and warp, leading to the same sensation. You may also tend to keep one foot "riding" on the brake without realising it. This can also cause overheating. Finally, if your vehicle has been sitting unattended for some time in a rainy climate, the metal discs may accumulate a surface of rust. This can interfere with performance and cause shuddering.

How Can This Be Fixed?

To determine if your discs are warped you can first do a visual check simply by spinning the disc by hand with a wheel off. If it does not move freely, ask your mechanic to check its uniformity with a micrometre to check the thickness. Damaged discs may be serviced by shaving off a thin layer using a lathe in a machine shop. In bad cases though, you may have to have them replaced.

Don't Leave It For Long

Don't be tempted to just put up with this problem for any length of time. If the discs are badly warped then over time other pieces of equipment will become damaged, such as the brake caliper, which will invariably drive up the cost of the eventual repair.

For more information, contact a specialist like Noosa Radiators & Car Airconditioning.