Brake Problems: How to Repair a Brake Pad Power Boost Unit

  • 2-3 hours
  • Intermediate
  • 50-125
What You'll Need
Needle nose pliers
Socket wrench
Socket extension
Slip joint pliers
New cotter pin
Adjustable wrench
What You'll Need
Needle nose pliers
Socket wrench
Socket extension
Slip joint pliers
New cotter pin
Adjustable wrench

When it comes to brake problems you are going to want to take care of them as quickly as possible. Trying to drive around with faulty brakes is an accident waiting to happen. Sometimes the problems is a simple fix that could have been done without a lot of expense on your part. One such repair is to the power boost unit. This unit actually multiplies the force that is applied to the brake pad to help stop the car quicker. After several years of use, the unit may have some leaks caused by the pressure that it builds. When this happens you will need to replace it.

Step 1 - Locate Push Rod on Brake Pedal

On the brake pedal you will find that there is a cotter pin that connects the pedal to a push rod. This rod is what activates the power boost unit. Using a pair of needle nose pliers, pull the cotter pin out of its position to disconnect the rod from the pedal.

Step 2 - Remove Mounting Plate

You will see that there is a power booster mounting plate located on the firewall right behind the brake pedal. Use your socket wrench and remove the 4 bolts that are holding it in place.

Step 3 - Disconnect Vacuum Hose

Move to the inside of the engine compartment and locate the vacuum hose that is connected to the unit. You will need to use some needle nose pliers to release the pressure on the compression clamp that holds it in place. Work the tube free until you can remove it.

Step 4 - Remove Brake Booster

Unbolt the booster from the brake master cylinder. This will require a socket wrench to remove the 2 bolts that hold them together. Once the bolts are removed you can then take out the faulty power booster.

Step 5 - Replace with New Booster

Set the new power booster in place by pushing the rod and mounting studs through the firewall so you can connect them to the brake pedal. Connect the booster to the master cylinder by starting the 2 bolts by hand. This will make sure that you do not cross thread the bolts. Once they are tightened enough with your hand you can finish them with your socket wrench. Replace the vacuum tube into position by sliding it over the nozzle and pushing it into place.

Step 6 - Install Rod

Once you have the work done in the engine compartment you will need to move to the driver's area. Connect the 4 mounting bolts back into position by tightening them with the socket wrench. Lift up the push rod and and connect it to the brake pedal with the use of a new cotter pin. Secure the pin by bending back the prongs.

Step 7 - Test Drive

Now that the new brake power boost unit is installed you should take the car on a short test drive. Do not simply jump in your car and start on a long trip. If there are any other problems, or adjustments that need to made, you will find out with a short test drive.