Depress the brake pedal several times with the engine off and make sure there's no change in the pedal reserve distance. Depress the pedal and start the engine. If the pedal goes down slightly, operation is normal. Airtightness check: Start the engine and turn it off after one or two minutes. Depress the brake pedal slowly several times. If the pedal depresses less each time, the booster is airtight. Depress the brake pedal while the engine is running, then stop the engine with the pedal depressed. If there's no change in the pedal reserve travel after holding the pedal for 30 seconds, the booster is airtight. Removal: Power brake booster units shouldn't be disassembled. They require special tools not normally found in most automotive repair stations or shops. Because of its critical relationship to brake performance, the booster should be replaced with a new or rebuilt one. Disconnect the electrical connectors from the booster. Disconnect the vacuum hose leading from the engine to the booster. Be careful not to damage the hose when removing it from the booster fitting. Remove the
Brake Master Cylinder. Remove the left side lower finish panel from the instrument panel. Locate the pushrod clevis connecting the booster to the brake pedal. Remove the clevis pin retaining clip with pliers and pull out the pin. Remove the four nuts holding the brake booster to the firewall; you may need a light to see them. Slide the booster straight out from the firewall until the studs clear the holes. Installation: Installation procedures are basically the reverse of removal. Make sure the clevis pin retaining clip is fully seated. After the final installation of the master cylinder and
Brake Lines, the system must be bled and the brake pedal height and freeplay must be checked. Carefully test the operation of the brakes before placing the vehicle in normal operation.