Brake discs

The brakes are intended to slow the vehicle down or bring it to a halt reliably. The brake system is exposed to high thermal and mechanical loads and wears out over time. For this reason, the brake discs should be subjected to at least one visual inspection at regular intervals. ORIGINAL brake discs are precisely tailored to the respective vehicle in terms of their material and properties and are precisely processed. They therefore have a long service life and harmonise perfectly with the other ORIGINAL components of the disc brake. By using original parts, the brake discs need to be changed less frequently.

In addition to the function of the brake discs, we present the different types of brake discs in the lower part of the page and show how you can recognize the wear. Last but not least, you will find tips on what you should bear in mind when changing brake discs.

How does the brake disc actually work?

The brake disc is part of the disc brake. When the brake pedal is pressed, the master brake cylinder is activated and the pressure of the brake fluid is passed on. Now the brake caliper and thus also the brake pads are pressed by the brake pistons against the brake disc. The brake disc moves at the same speed as the wheel while driving. The friction of the brake pads on the brake disc converts the kinetic energy in a disc brake into heat energy. This reduces the speed and the vehicle can be slowed down or brought to a halt.

There are different designs of brake discs. Not all of them fit in every car. Therefore, the components of a disc brake must be matched to the vehicle-specific requirements before purchase. The following designs are distinguished:

1. Full brake discs: They are partly already installed ex works and are the cheapest to buy. By the way, many small cars only have brake discs on the front axle. The rear axle is often equipped with drum brakes, because the parking brake can be easily integrated.
2. ventilated brake discs: The friction surface of the brake disc can reach temperatures of up to 700 degrees Celsius and this heat must be dissipated as quickly as possible. This is ensured by the larger surface area of the ventilated brake discs and the webs that connect the friction rings together. Here a suction is created which guides the air from the inside of the brake disc to the outside. Friction rings are the part of the brake disc on which the brake pads press from outside. Ventilated brake discs are two-piece brake discs where two friction rings are connected by webs.
3. perforated / slotted brake discs: The perforation or slotting of the brake discs ensures even faster cooling and prevents fading. Fading is understood to be the reduction of the braking effect through heating. In addition, water can be drained off the friction ring more quickly. These brake discs are especially recommended for vehicles with a higher performance.

To detect wear on the brake disc

In addition to the high thermal and mechanical loads, external influences such as dirt and dust from the road or gritting agents also affect the material of a brake disc. The components of a disc brake wear out and have to be replaced over time. You can inspect the brake disc yourself and subject it to a visual inspection. The brake discs have a minimum thickness specified by the manufacturer. The exact minimum thickness can be found in the manual or in the service booklet.

When driving, the following signs may indicate that the brake discs need to be replaced:

• The steering wheel starts to vibrate during braking
• The brake disc overheats and starts blue
• The braking effect has noticeably decreased
• The braking effect of the vehicle is irregular

Flugrost on the brake disc is no cause for concern and does not affect the function or the braking performance. It occurs during long periods of standing or in damp weather and should disappear after a few braking operations.

What do I have to take into account when changing the brake discs?

The brake disc change is basically not difficult, but should only be carried out with experience or in a specialist workshop. Only in this way can damage to the vehicle be prevented. During installation, for example - often in vehicles with powerful engines - there are brake discs which are directionally dependent. The components of the disc brake must not become dirty and no grease or similar must be allowed to get on the brake disc. When changing the brake discs it is necessary to clean the brake calliper, the pad holders and above all the wheel hub with a wire brush or a brake cleaner and to use a brake pad paste. This is applied to the guide surfaces on the brake calliper and to the back plate of the brake pads.

When the ORIGINAL brake discs are replaced, you should also replace the brake pads and the wear warning contacts. It is also important to always replace the brake discs and pads in pairs. For this reason, we have put together ORIGINAL brake sets for many vehicles, with which you can also save money.

Here you will find the suitable parts!

No matter whether you only need the ORIGINAL brake discs or a brake set, by entering your vehicle data, the potentially suitable components of a disc brake are displayed directly in the shop. If you are still unsure, please contact our Customer Service with the 17-digit chassis number. For vehicles of the Volkswagen Group, the 3-digit PR number, which can be found in the vehicle registration document, also helps us.