How to Rebuild a Lucas Caliper

Solid brakes are a critical safety component in any automobile. Modern disc brake systems employ a combination of master cylinders and wheel calipers. If your car pulls to one side when you apply the brakes or if you notice a loss of brake fluid, chances are that one of your wheel calipers is not functioning properly and should be rebuilt. Fortunately, once the caliper is out of the car, rebuilding it is fairly easy.

Instructions

1

Secure the wheel caliper in the bench vice. Gently apply air pressure to the brake line so that the piston slides almost all the way out. Wiggle the piston with your fingers and pull it out of the caliper. If it is stubborn, remove the piston with the channel-lock pliers. Once the piston is out, remove the piston boot and seal, using the flathead screwdriver to pry it out of the groove.

2

Remove the black, rubber piston seal from the piston by inserting the flathead screwdriver into the groove and prying it out. Slide the piston seal off and discard it. Clean the piston and caliper bore with brake-cleaner spray.

3

Install the new piston seal. Dip the new seal into new brake fluid. Ensure that it is oriented properly and slide the new seal onto the piston. The wide edge of the seal should be facing toward the end of the piston that slides into the caliper. Examine the piston and caliper bore and ensure that both are spotless and clean.

4

Dip the piston and seal assembly into new brake fluid and carefully slide the piston into the caliper. Ensure that the new seal seats properly as the piston enters the caliper bore. Clean the boot seal groove with brake-cleaner spray and install the new cylinder boot and seal. Tap it gently into place with a large socket and the rubber mallet. Spray the entire assembly with brake cleaner and remove any residual brake fluid from the exterior. The caliper is now ready to install.