Disc Brake Cooling
Disc Brake Cooling The cooling of the brake disc and its pads takes place mostly by air convection, however wheel hubs also conducts away some of the heat. The rubbing surface between the rotating disc and the stationary pads is exposed to the frontal air stream of the vehicle and hence to the directed air circulation. Therefore, under continued brake application the disc brake is considerably more stable than the drum brake. Also, the high conformity of the pad and disc, and the uniform pressure allows the disc to withstand higher temperatures compared to the drum brake. Since far less distortion takes place in discs compared to drums, the disc can operate at higher temperatures. Also, the disc expands towards the pads, whereas the drum expands away from the shoe linings. Consequently, in the hot condition the disc brake reduces its pedal movement, but the drum brake increases its pedal movement. The discs are made of cast iron and are ventilated to considerably improve the cooling