How to Change the Brake Booster on a 97 GMC Sonoma

The brake booster on a 1997 GMC Sonoma is the main component that pushes the brake fluid to all of the braking components. When the brake pedal is pushed in, the brake booster pressurizes the master cylinder. The brake fluid then flows out of the master cylinder and into the brake calipers. If the brake booster ever loses its vacuum, it will not be able to stop the truck in a safe and efficient manner. Replace it immediately to prevent unsafe braking.

Instructions

1

Park the 1997 GMC Sonoma on a level surface and open the hood. Locate the 12-by-12 round brake booster mounted to the rear driver-side firewall. Pull the vacuum line out of the front of the brake booster with your hand.

2

Move back to the driver-side door. Look behind the brake pedal with the flashlight and locate the clip that secures the brake booster linkage to the brake pedal. Pry the clip out of the linkage with the flat-head screwdriver. Put the clip in a safe place.

3

Locate the master cylinder that is secured to the front of the brake booster. Loosen and remove the metric bolts from the master cylinder with an open-end metric wrench. Carefully pull the master cylinder straight off the brake booster and set it down on top of the engine compartment.

4

Loosen and remove all of the bolts from around the brake booster with a ratchet, extension and socket. Pull the brake booster straight off the firewall. Remove the old gasket from the brake booster or the firewall.

5

Position the new gasket over the back of the new brake booster. Put the new brake booster back over the firewall. Screw all of the bolts on and tighten them by hand. Tighten the bolts in a alternating sequence with the ratchet, extension and socket.

6

Slide the master cylinder back onto the front of the brake booster. Screw the bolts on and tighten them with the open-end wrench.

7

Connect the brake booster linkage to the back of the brake pedal. Push the clip back through to secure the linkage to the brake pedal.

8

Push the head of the vacuum line into the opening on the front of the new brake booster. Double-check all of the bolts and nuts for tightness.