Annoying or dangerous

What should I do if my brakes squeal?

(Bild: Stephan Schätzl)

There are various causes of squealing brakes. Some are harmless, others are not. The question for drivers is: Where is it coming from? What can I do? And: Should I do something?

Thomas Schuster, vehicle expert at the KÜS expert organization, provides the answers: "The unpleasant noise can have various causes, but there is usually no acute danger. Disc brakes in particular are susceptible to occasional noise development. However, if the squealing is constantly audible, the car should definitely be taken to the workshop.

The fact that brakes can squeal at all is due to their design. When decelerating, the brake pads are pressed against the brake disc; when the pedal is released, the components also completely separate from each other again. Ideally, at least. In practice, however, it can happen that the pads and disc still touch slightly, resulting in vibrations that are audible as a squealing sound.

Harmless dirt on the brakes
There are various possible reasons for unintentional contact between the components. The most common causes are probably dirt from brake dust, rust or road grime. As a rule, the annoying dirt can be carefully removed from the brakes. Washing the vehicle can also help.

Symbolic image

(Bild: stock.adobe.com)

Overheating or incorrect parts
Even in brand new cars, the disks and pads are often not yet perfectly adjusted. However, any squeaking will subside over time. If the noise remains audible, however, there could also be more serious causes. For example, incorrectly fitted brakes or brakes assembled from unsuitable parts - possibly an effect of misunderstood thriftiness when tightening screws at home or in the garage. Glazed discs and pads can also cause squealing. This occurs, for example, when the system overheats due to extreme loads.

In the latter case in particular, you should visit the garage quickly, as the glazing is accompanied by a loss of braking power. In this case, only a replacement will help. Incidentally, worn brakes do not usually squeal; they tend to make a dull grinding noise.

SPX