High Quality Content by WIKIPEDIA articles! A vehicle brake is a brake used to slow down a vehicle by converting its kinetic energy into heat. The basic hydraulic system, most commonly used, usually has six main stages. The brake pedal, the brake boost (vacuum servo), the master cylinder, the apportioning valves and finally the roadwheel brakes themselves. A friction brake is a type of automotive brake that slows or stops a vehicle by converting kinetic energy into heat energy, via friction. The heat energy is then dissipated into the atmosphere. In most systems, the brake acts on the vehicle's roadwheel hubs, but some vehicles use brakes which act on the axles or transmission. Friction brakes may be of either drum or disc type.