Caliper pistons should be pushed back into their bores. These pistons must slide easily into their bores, should any difficulty be experienced, both calipers should be overhauled to ensure that the pistons retract properly.
When the pistons are pushed back the condition of the caliper can be checked. The first area to check is the caliper slides, they should be able to move their full distance with light pressure. Tight or seized slides will prevent the pads from releasing from the disc. This will lead to pad overheating,excessive disc wear and possible brake fade, it is important that the slides are able to move freely.
Safeline recommends the slides to be removed completely, cleaned and lubricated with a high melting point grease such as CV joint grease. The dust boots should be inspected, if they are torn or brittle they should be replaced to stop water and dirt from entering between the piston and the caliper body. The caliper should be thoroughly cleaned with brake part cleaner, when reinstalling the caliper make sure that any anti rattle springs or clips are positioned correctly.