Fyi. The rear caliper of a for focus cannot be compressed with a compression tool. It must be screwed in with a special tool that fits two depressions in the piston.
I really want to know where you got that tool for the piston from. Can get similar things in my area but they re all so bloody flimsy
All you need to know with the mystery removed on how to fix do a simple bolt on bolt off job. Thank you. So much