This is used to reduce a vehicle's speed. The service brake is actuated by the driver's foot and it must be possible to graduate this braking action. Service brakes are designed as friction brakes and are subject to wear.
The brake system's role on a commercial vehicle is to reduce speed as necessary, to bring the vehicle to a halt or to keep it stationary. It consists of several components. The power supply includes all parts that deliver, regulate and prepare the energy required for braking. Components in the actuating device initiate the brake system's effectiveness and control braking. Transmission device components serve to forward the energy managed by the actuating device. The wheel brakes convert some of the vehicle's kinetic energy into heat (frictional heat) and thus slow the vehicle. The brake system on a commercial vehicle is basically subdivided into four functional areas: the service braking system, secondary braking system, parking braking system and endurance braking system. Braking systems for commercial vehicles with a permissible total mass over 7.5 tons almost always (at MAN exclusively) operate using compressed air.