Figured out a trick for getting stuck brake caliper pistons to move without damaging the boot

Was working on a 2012 Ford Focus last weekend. Rear caliper piston was seized solid. Tried the usual C clamp and screwdriver method, nothing. Kept tearing the rubber boot. Then I remembered a tip from an old coworker. Took a small flathead screwdriver and gently pried the outer edge of the boot lip just enough to let compressed air in. Hooked my blow gun to the bleeder valve with a rubber hose adapter. Popped right out with no boot damage. Anyone else got a clever way to free up stuck pistons without trashing the seals?

3 comments

3 Comments

linda1141mo ago

So you basically had to give it a lil pep talk with compressed air.

the_thea1mo ago

Used to roll my eyes at the compressed air thing (felt like internet folklore, you know?) but after watching my buddy's old Ford finally crank after one little blast, I'm a full convert.

lilya761mo agoTop Commenter

Tried that air trick on a rusty 2005 Subaru and it worked like a charm. @linda114's pretty much right, that little burst of air is all the encouragement they need sometimes.