| Description and Operation WARNING:Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with the eyes. Wash hands thoroughly after handling. If brake fluid contacts the eyes, flush the eyes for 15 minutes with cold running water. Get medical attention if irritation persists. If taken internally, drink water and induce vomiting. Get medical attention immediately. Failure to follow these instructions may result in personal injury. The diaphragm-type brake booster: - is self contained
- is mounted on the engine side of the bulkhead
- uses engine intake manifold vacuum and atmospheric pressure for its power
- utilizes a check valve to provide temporary pressure when its vacuum is reduced
Active Brake Booster The active brake booster is fitted to vehicles with stability assist. In a stability assist event, the stability assist control unit drives the solenoid valve in the brake booster. As a result, atmospheric pressure is applied to the back of the following diaphragm so that a pressure of approximately 10 bar is built up on the pump suction side without actuation of the brake pedal. Right-hand drive shown (Left-hand drive similar) | 
