Chevrolet GMC Hydro-booster

Hydraulic brake booster (Hydro-booster) introduction:
Hydraulic brake boosters make efficient use of the existing energy supply system in a vehicle. The hydraulic pump is used to supply, for example, power steering with the necessary high-pressure oil. It is only about the same size and weight as the tandem master cylinder. It has a substantially higher runout pressure than vacuum boosters, and is not dependent on a vacuum supply. It can therefore also be used without problem on diesel engine vehicles or on vehicles whose engines produce low vacuum levels.

If the steering pump fails, the hydraulic pressure reservoir contains an adequate pressure reserve to apply the brakes several times with full boost effect. Even after this pressure reserve has been used up, it is always still possible to brake – although without reinforcement, and therefore with a significantly greater force from the foot.