S13 Brake Problem.. stumped

[s14Geoff]

Alright guys, went to do a simple brake pad and rotor replacement today. This is the first time I've done it on this car in the short time I've owned it. Front calipers came off just fine but the rears were like they were constantly engaged (which me and my dad came out to find seemed like that was true). Looking at the pads the fronts seemed new and the rears were down to practically metal. We had to take a hammer to get the calipers off the rear rotors. When we did finally get them off we couldn't compress the brake piston. We took the bleed off, disconnected the lines from the master cylinder, and the piston STILL wouldn't compress.



What was even more wierd is after we went inside for a little and after we disconnected the brake lines the piston pushed itself out further, without us pushing a brake pedal or e-brake.
This is the right rear caliper (the one that pushed itself out and wouldn't compress)



and this is the left rear caliper (we didn't mess with this one at all except take it off)




Does anyone have a clue as to what the problem is? We thought it could be the master cylinder but if the lines are disconnected from the cylinder and the piston still won't compress how could it be that? The e-brake didn't seem to be the problem either as we engaged and disengaged it multiple times and seemed to be disengaged when tryed to pull the caliper off. Is the caliper just old and worn out? Maybe time for a z32 brake upgrade...
Thanks guys. Sorry for the essay of a post lol

[s14Geoff]

Found out you have to twist and push for the rear piston
but that doesn't solve why the brakes were stuck engaged
anyone have any idea why this would be happening? thank you

[Hijacker]

The calipers are probably shot. It happens. Just get some new ones from your local auto store.

[PercieBlaze]

i second them being done, all my calipers on my 40 went when i changed the brakes.

[Jake The Snake]

3rd them being shot. They're fairly cheap especially if you bring in a core to the shop. I was stupid and kept driving on my first s14 and the locked up on the highway. Don't be like me.

Make sure you put that brake lube stuff on the sliders when you install new ones.

[bloodwar45]

the way you cant test is pump your brakes and if they are locked up loosen the bleeder screw if that unlocks them then most likely its the master if they stay locked its the calipers or slider pins i just went through this last week