Two-stage brake servo
The two-stage brake servo ensures fast-action braking combined with short pedal travel, good controllability and reduced braking effort up to the point at which ABS is activated (full braking). Up to a brake pressure of about 45 bar, known as the comfort braking range, the brake servo operates with the standard factor 5 boost. This is approximately equivalent to normal braking, e.g. at a red light. If the driver brakes harder, if brake pressure exceeds 45 bar for example, brake assistance is increased to factor 10. The pedal force that has to be applied when braking is reduced significantly as a result.