Rebuilding a RacingBrake caliper with new pressure and dust seals

  1. Disconnect the banjo bolt (brake line) from the caliper.
  2. Detach the caliper from the adapter by loosening the two caliper bolts on top of the caliper.
  3. Remove the brake pads from the caliper.
  4. Lay the caliper flat on a padded surface.
     
  5. Place several pieces of corrugated cardboard (cut to approx 4.5” x 3”) in the space inside the caliper. The cardboard will act as padding when the pistons eject from the caliper. The overall thickness of the multiple pieces of cardboard should be about 1.5”


     
  6. Induce compressed air (about 90 psi) into the caliper via the banjo bolt connection. Several of the pistons should eject from the caliper.



  7. It may be necessary to use thin cardboard shims to get certain pistons to eject. Eventually, all four pistons will come out. It may be necessary to use your hands to pull out the last one or two pistons.



  8. Inspect each piston surface to make sure there is no visible damage. If at this point, you wish to separate the caliper halves, you can do so in order to make the rest of the process easier. You will need blue threadlocker (such as Loctite) in order to reassemble the caliper halves.

  9. Use a thin and soft metal tool such as a .004” feeler gauge to gently pry out the old dust seal and pressure seal from the piston cylinder. Repeat for all four piston cylinders.

       

  10. Replace the old seals with the new ones.



  11. Replace the pistons and push them back into the caliper by hand.
     
  12. Reattach the caliper to the adapter and reconnect the brake line. If you need to reassemble the caliper, use blue threadlocker and torque the caliper bolts to 21 foot-pounds.