Caliper rebuild

1

Wear clean disposable gloves to prevent contamination. Make sure the groove where the main seal fits is spotlessly clean. Dip the new main seal in some fresh brake fluid, then fit it inside the caliper. Carefully push the new main seal into position with a blunt tool (not a pick or a scribe).

2

Check the new outer seal/dust boot fits into the upper groove on the caliper (it will be removed in the next step and refitted). This must be thoroughly clean to ensure the piston will go back in to the caliper. If it isn’t, carefully clean around it with a blunt tool and wipe away any dirt.

3

Remove the outer seal/dust boot and fit it on to the piston with the lowest part hanging off the bottom of the piston body. Carefully offer it up and manoeuvre the seal inside the caliper, holding the piston at the same time.

4

When the seal is properly located, the piston should push in with firm finger pressure. Apply brake fluid to help fit the piston. Do not use any more force, such as vice grips or water pump pliers. If the piston is too tight, the seal is probably not in correctly.

5

Once the piston has been pushed inside the caliper, make sure the outer seal/dust boot sits in the groove on the wall of the piston. This ensures the walls of the piston remain protected from dirt and moisture.

6

If a piston requires a windback tool to adjust it, then assembly is the same as the previous steps, but once the piston is pushed into position, use the windback tool to move it further in.