How To Replace a Brake Booster

The brake booster is a vacuum-driven component responsible for providing vacuum pressure to the brake system. The pressure generated by the booster improves the braking in your vehicle by creating additional clamping force for the brake caliper. Brake boosters rarely fail, but when they do, you'll know it. You will feel a dramatic decrease in the brake power being generated when you press on the brake pedal. When this happens, you'll need to replace the unit.

Things You'll Need

  • Socket wrench and socket set
  • Tube-nut wrench
  • Pliers
  • New brake booster
  • Masking tape
  • Permanent marker
  • Secure the tube-nut wrench to the tube nut on the brake line at the master cylinder. Slip the tube-nut wrench over the brake line just before the tube nut that is connected to the master cylinder. Orient the wrench so that it fits over the tube nut on the end of the brake line.

  • Turn the tube nut counterclockwise to loosen and remove it. Mark the location of all of the brake lines and remove the lines by pulling them out of the master cylinder.

  • Remove the electrical connector running to the brake master cylinder reservoir cap.

  • Remove the master cylinder mounting bolts.

  • Slide the master cylinder off the brake booster diaphragm.

  • Remove the brake booster to firewall mounting bolts.

  • Remove the cotter pin that secures the brake pedal to the brake booster connecting-pin connection. The cotter pin slides into the connecting pin, which secures the brake pedal to the brake booster diaphragm inside the passenger compartment. To remove it, pull it out with a pair of pliers.

  • Pull out the brake pedal to brake booster connecting pin.

  • Pull out the brake booster through the engine bay.

  • Install the new brake booster; installation is the reverse of removal.