How to Repair a Brake Booster

What You'll Need
Line wrench
Socket wrench
Service manual
Replacement brake booster
Measuring tape and a pencil

The brake booster on a vehicle is the vacuum-powered system that causes the ABS system to kick in and apply the right amount of pressure to the brakes, ensure that they work. If the brake booster happens to lose power, you need to repair or replace the booster in order to ensure that your ABS braking system continues to work. Some people may prefer to go to an auto-mechanic or a garage, but those keen on saving money or performing their own car repairs can try to replace the brake booster themselves by following these steps carefully.

Step 1 - Removing the Master Cylinder

You will need to reach into the engine cavity of the car and locate the master cylinder. This can be found in the front portion of the car, along the driver's side. Take your line wrench, place it over a brake line, and turn it. Make sure that you note the place where you removed the brake lines from, using either a tape or a marker pen. Repeat with the other brake line. Once the master cylinder is free of the brake lines, use the other wrench to remove the cylinder from the car.

Step 2 - Removing the Old Booster

The brake booster can now be removed from the brake pedal. You may need to use pliers to take off the pin that is holding the brake booster in place. You can also use the socket wrench to remove the bolts that keep the brake booster connected to the firewall and extract it from the car cavity. You should examine the brake booster to make sure that it has developed a flaw and you are replacing the damaged part.

Step 3 - Connecting the New Booster

The replacement booster can now be bolted into the place of the old booster. Using the socket wrench, connect the booster to the firewall using the previous bolts and replace the pin in the booster push rod, holding it firmly to the brake pedal. You can now add the master cylinder back after checking that it is completely clean and that there is no damage to the cylinder itself.

Step 4 - Replacing the Master Cylinder

The best way to replace the master cylinder is to reverse the steps you used to extract it from the engine. Re-attach the cylinder to its housing again using the socket wrench, tightening the bolts securely to make sure that it does not move. You should now only have the brake lines to connect back to the cylinder. Take one brake line, and re-place it against the tape or mark that you made when removing it from the cylinder. Using the tube nut wrench, screw it back onto the master cylinder. Repeat with the opposite side.

Bleed brakes as outlined in car service manual.

Check that all of your pieces are correctly connected by testing the brakes before you finish.