Normal Operating Characteristics

Brake pedal application of the Hydro-Boost system differs in some respects from a vacuum type power brake system in the following manner:

1. As pedal is depressed, a slight power steering pump noise may be heard until booster run-out.
2. Application of pedal through run-out may not necessarily be smooth due to internal ratio change. It is possible to push the pedal past run-out because the pedal ratio is higher. The pedal becomes hard at the end of vacuum booster runout.
3. On the first full application of the brake pedal, a slight hissing sound may be heard. The hiss is the accumulator charging and the noise should go away in a short period of time.
4. As the brake pedal is depressed hard, a slight kick-back of pedal may be felt.
5. If the vehicle is started with the pedal depressed, the pedal will fall away slightly then return to approximately the same position.