best way to get brake calipers unseized

I have a set of narrow glide dual discs and both the pistons in the calipers are seized i used a vice to compress them about 1/8 inch. i let them soak in wd 40 for a day then used an air compressor to try and blow the piston out but no such luck. any ideas

Originally Posted by Trevor04

I have a set of narrow glide dual discs and both the pistons in the calipers are seized i used a vice to compress them about 1/8 inch. i let them soak in wd 40 for a day then used an air compressor to try and blow the piston out but no such luck. any ideas

Had that happen on a T bird I owned many years ago. A buddy, who's a mechanic, completely disassembled the caliper, soaked all the parts in wd40 (I think) and it was all set. It literally took him 20 minutes. I would assume mc calipers would be no different.

i had a seized piston in a banana caliper because the rubber boot rolled up and got stuck, air wouldn't work so i put a torch to it and burned that bitch out just be careful not to hold it in one place too long or you'll melt the aluminum

Unscrew the tip of a grease gun and screw the gun into the caliper. You only have to catch a thread a tiny bit (in case the threads are different) for it to hold. Pump grease into the caliper and it will push the piston out. It's messy, but has always worked for me, even in the worst cases.

Mine were seized also. I soaked 'em in WD40 over night, then hooked the caliper up to my compressor. Gave it all the pressure my compressor could deliver. No luck either. Took a screwdriver and my hammer and GENTLY tapped on the side of the pison (not on the surface that goes donw in the caliper - just the part where the rubber seals). 2 minutes later I shot that baby up in the ceiling - still got the mark to remind me.
Went inside, changed my shorts and did it all over again with my other caliper.

Originally Posted by Stabler

Mine were seized also. I soaked 'em in WD40 over night, then hooked the caliper up to my compressor. Gave it all the pressure my compressor could deliver. No luck either. Took a screwdriver and my hammer and GENTLY tapped on the side of the pison (not on the surface that goes donw in the caliper - just the part where the rubber seals). 2 minutes later I shot that baby up in the ceiling - still got the mark to remind me.
Went inside, changed my shorts and did it all over again with my other caliper.

I did one of mine the same way only the piston shot across the garage, through the window and into the front yard!