How to Install a GMC Brake Boosterby Russell Wood
The brake booster on a GMC uses vacuum power that the engine generates to give a power assist to the braking system. Unfortunately, the brake booster is not a serviceable unit. If the booster fails, then the old booster has to be removed from the truck so that it can be replaced. Once you have the old booster removed, then you have to install the new booster. Installing a new booster should take about 30 minutes to do.
Pop the hood. Slide the brake booster into the firewall so the vacuum port is located on the top passenger side corner of the booster. Plug the vacuum line and check valve into the vacuum port on the booster with your hands.
Look under the dash. Secure the booster to the GMC with the 3/8-inch ratchet and socket. Put the brake booster linkage onto the brake booster with your hands. Install the brake switch onto the end of the pedal, then install the factory clip onto the brake pedal to lock it in place.
Slide the master cylinder onto the brake booster. Bolt it down with an open-end wrench. Start the GMC and test the brake pedal to make sure it works correctly.