Stuck rear calipers

[Jamieg285]

Before you start pushing the piston back with clamps or other mechanical devices, with the caliper off pump the brakes a bit.  Not too much that the piston pops out completely, but enough to push it out a bit more that it would when fitted.  This should give you access to better clean up the ridge of crud that is likely causing you problems.

Trying to push it in before cleaning this up is likey to ruin the seals,