How to Repair a Vacuum Brake Booster on a Chevrolet Truck

The Chevrolet truck uses a vacuum-assisted brake system, which multiplies the braking force, and reduces the effort it takes for the driver to press the brake pedal. The vacuum is always available when the engine is operating, which makes the system efficient. The vacuum diaphragm---or the brake booster---is connected to the intake manifold via a vacuum hose. This is where the booster obtains the vacuum.

Instructions

1

Set the parking brake. Unplug any electrical connections at the booster or that may be in the way of removing the booster. This depends on the year and make of Chevrolet truck.

2

Unbolt the master cylinder from the brake booster and pull it off the studs. Do not disconnect the brake lines. Take care to avoid bending the brake lines as you are working with the master cylinder.

3

Loosen the clamp on the vacuum hose at the check valve using the screwdriver. Pull the hose off the check valve. If your year and model Chevrolet has a brake light switch attached to the vacuum booster, remove the brake light switch using the appropriate socket.

4

Disconnect the booster pushrod at the brake pedal using the appropriate socket. Remove the booster mounting nuts, which are located on the inside of the firewall, using the appropriate socket or wrench.

5

Lift the booster off the firewall and remove the gasket.

6

Position the new booster and gasket on the firewall and screw the mounting nuts onto the booster studs. Tighten the nuts to 21 foot-pounds of torque on all years and models except 1996 through 1998. On the 1996 through 1998 years and models, tighten the nuts to 26 foot-pounds of torque.

7

Reinstall the booster pushrod and master cylinder. Reinstall the vacuum hose at the check valve. Start the vehicle and check for proper operation of the booster.