GM Service Manual Online
For 1990-2009 cars only

The booster assembly is located along the bulkhead in the left side of the engine compartment, between the brake pedal and the master cylinder. The assembly is designed to take advantage of the vacuum produced by the engine. The applied force created when the brake pedal is pressed is mechanically increased with the assistance of the engine vacuum.

If the booster assembly becomes inoperable, brake operation will not be lost. The force of the brake pedal being pressed will still be transferred through the control valve, booster piston, piston rod and onto the master cylinder. The brake system will still operate, but the pedal will be harder to press.

The booster assembly in this vehicle is not serviceable and must replaced as a unit.