Having issues with my front brakes binding and I think it is my calipers, but I don’t understand why or how. Back story and progression: 2004 GMC Envoy SLT 125K miles October last year I started getting brake drag and turned out it was my parking brake on drivers rear that was refusing to release. Couldn’t get it to release no matter what I did and since I have never used it, I cut the cable to that side (noticed further up the covering was damaged so needed replaced anyways). During this time the Drivers front was starting to not let up, so I took it apart and inspected. Piston in the caliper was frozen. Went and bought a new caliper set for both fronts and decided to change the Brake fluid as well (was almost pitch black – previous shop never really changed it). Transferred old slide pins to the new calipers, lubricated, installed. Bled brakes in order to flush out the old stuff. Everything was doing fine. March of this year the drivers front brake started to get tight to where the caliper wasn’t fully releasing. (Recent divorce so money was tight), couldn’t quite figure it out after checking it out again and put it on my to do list when I had the funds. Currently the passenger front brake has started binding and not wanting to release either and its heating up the rotors as of yesterday. You can hear the pads contacting with the rotors the entire time driving and they started to squeal on drivers side, but there isn’t any metal contact from the pad. And lots of brake dust. Today I went through the motions to troubleshoot. My brake pedal has felt a little stiff for a long while now, but it passes all the brake booster checks. Pulled the ABS fuse and went around the block, it felt a little bit better, but it could have been just wishful wanting. Put the fuse back in. Pulled the tires off and neither caliper was movable. Rotors could be turned with some moderate effort. I cracked the bleeder valve on both to see if a bad flex line could be keeping pressure on the calipers, but no luck. Never heard of both calipers going bad at the same time. Pulled the calipers off to inspect them. They both took more pressure than they should have to press back in with a C-clamp. Sliding pins on passenger side are normal with that little bit of squish to them, but the pins on the drivers side keep sucking themselves back in flush (which way is normal pushing out against caliper or pulling in). What I found interesting was the rubber boots around the pistons, both on drivers side and one on passenger side, appeared to look like they had air puffed up inside them. I found this very strange. The calipers are still under warranty I believe and I can take them in, but is there something else that is going on here that could be causing this braking problem?