System overview

Fig 1: Illustration For Step 1-6

Courtesy of SAAB-SCANIA OF AMERICA, INC.

1. Brake pedal
2. Servo unit
3. Master cylinder
4. Front brake caliper
5. Rear brake caliper
6. Brake disc

The foot brake system is operated with the brake pedal and acts hydraulically on all wheels. When the brake pedal (1) is pressed, it acts mechanically via the servo unit (2) on two pistons in the master cylinder (3).

The servo amplifies the outgoing pedal force and the increased pressure on the pistons in the master cylinder is conveyed simultaneously but divided into two hydraulic circuits to the front (4) and rear (5) wheel brakes. The brake calipers front and rear are self-adjusting, i.e. they continually compensate for wear in the brake pads.

Depending on the version of the braking system, the rear brake discs are either solid or ventilated. See also BRAKES/ABS 5.4/TECHNICAL DATE - TECHNICAL DATA  - BRAKE DISCS, Brakes  - TECHNICAL DATA  - BRAKE PADS  and BRAKE CALIPER  .