Power Booster

The power booster is a single diaphragm, vacuum operated unit. When brakes are not applied, there is no power assist because equal pressure (vacuum) exists on both sides of power booster diaphragm. When brakes are applied, vacuum is present on one side of diaphragm, and air, at atmospheric pressure, is admitted to other side. Power assist is provided when there is unequal pressure on opposite sides of diaphragm. When brakes are released, atmospheric pressure is shut off, and vacuum source creates equal pressure on both sides of diaphragm by means of a one-way valve in power booster.