Brake Booster
The power brake booster is a dual diaphragm, vacuum assisted power brake booster. The power brake booster reduces brake pedal pressure and travel distance. The booster is located on the left side of the bulkhead in the engine compartment, between the brake pedal and brake master cylinder and is divided into separate chambers by the diaphragm. The booster will not operate if vacuum is restricted or if any of the vacuum related power brake components fail. The booster is installed new as an assembly. If the power assist fails, the brake system will continue to operate with increased brake pedal effort. Diesel models use a belt-driven vacuum pump to provide vacuum for booster actuation.
A mechanically operated booster check valve controls power brake application and release in relation to pressure applied to check valve operating rod. See Fig 1. The power brake booster check valve is located on the front of the power brake booster. The check valve and grommet can be installed new separately. The check valve is positioned between the power brake booster and the power brake booster hose. The check valve closes when the engine is turned off. In the closed position, the check valve traps engine vacuum in the power brake booster and retains vacuum to provide several power-assisted brake applications with the engine off.