So much so that that one would think that they do not play a very important part in the scheme of things.
At times a brake caliper is called upon to operate at extreme temperatures whilst covered in sand and grit, it dares not seize when left wet and muddy. Calipers must retract freely when the brake pedal is released and must not leak any fluid, yet they are quite often totally ignored when brakes are reconditioned.
Have a look at the old pads to check if they have worn reasonably even, or if they show that our neglected caliper could do with replacement.
What about next time they are removed spare a thought for this most important item and at least clean it up, check for leaks under all the dirt and make sure that the pistons move freely and the dust seals are still intact, while trying to retract the pistons to fit the new pads in.
On some calipers the bleed screws can be seized - check em! Now, before assembly!
Grease the pins and slides if required to make sure that the caliper can centralise.
(We still recommend that all brake work is performed by a qualified mechanic).
AG for TT.