How to recognize worn brake discs?


Brake discs play an essential role in a car’s braking system. It is very important that they are always in good condition to ensure our safety and that of other users on the road. This is why it is essential to know when to change them.


First of all, let’s understand how the braking system works . It is a set made up of wearing parts (such as a chain or a timing belt ) and a hydraulic system in which brake fluid plays a major role.

The brake pads , on the other hand, are made up of linings and press on the brake disc when the driver presses the brake pedal. These pads are mounted inside the caliper on either side of the brake disc. These linings wear out over time and when worn, allow the pads to rub against the rotor, damaging it.

Concretely, the disc fixed on the hub, receives the friction of the pads during braking. This generates a frictional force which has the effect of reducing the speed of rotation of the wheel but generating a high temperature which ultimately deforms the disc. This is why it is necessary to change the brake disc after a certain time . It is a part which, due to its use, inevitably wears out over time, hence its name of “ wearing part ”.


The fact that the brake disc is under the wear dimension. This is a thickness value set by each disc manufacturer below which the disc becomes unusable. They say he is off the coast.

When an anomaly appears on the face of the disc such as scratches . They appear when worn brake pads rub against the disc. This is why it is important to do a regular platelet check.

With the increased temperatures due to the friction on its surface, the disc can deform, one then speaks of warped disc.

This same overheating also affects the disc color which tends towards blue. When you notice that the brake disc is turning blue, it must be replaced.

You have to change a cracked disc. When you identify an apparent crack in the brake disc, it is capable of breaking anytime, which is extremely dangerous.

A broken disc must also be replaced. The breakage occurs under the action of rust on the disc which damages.


The brake disc check should be carried out automatically if you have to change the front or rear brake pads. It is recommended every 30,000 km . Apart from the signs of wear mentioned above, it is recommended to change your brake discs every 60,000 km .

If the change of brake pads does not necessarily entail a change of disc, the change of brake disc must be followed by a change of pad.

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