If your calipers start leaking brake fluid, or the piston(s) are stuck, you can buy new calipers, but you can also consider rebuilding them, provided the caliper housing is still usable.
Rust is the big enemy of the caliper, if the brake fluid is not changed regularly or checked for moisture content (hygroscopic), the piston will get stuck over time due to a rust deposit. Removing it with the wire brush is not a good idea, the surface must be perfectly smooth, if this is not the case, leakage occurs, and you can start from scratch but now with new pistons.
Notes :
- If there is no leakage between the two halves of the caliper (if the caliper is in two pieces), do not separate them either. If a leak requires it, have the two halves checked for flatness and flatten them if necessary.
- The oil channels between the caliper halves (if any) are sealed with rubber rings. Never use universal rings, only those provided for this purpose. These rings are not part of the overhaul kits, if you need them, you must order them additionally (see options tab).
- You can only remove the pistons with air pressure. Do not use a screwdriver and hammer, as this will only damage the piston. For two-piston calipers, be sure to tighten one piston (e.g., with a hose clamp) and apply air pressure to the hose or brake line connection. The piston that is not tightened will then come off. Once a piston is removed, seal the hole with a rag and put a clamp on it to avoid losing the air pressure needed to remove the other piston. Use brake cylinder assembly paste (listed in the options tab) on the piston, on the inside of the caliper and on the seals around the piston and put it back in place.
All caliper overhaul kits are provided for overhauling one caliper.
Remark : The brand of the caliper should match, check what is mounted on your car and compare the picture before ordering. It is common that a different brand of caliper was installed at one time and then we cannot guarantee that these new pistons will fit.
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