brake problem, help a brother out

[spoolandslide]

this particular problem occurred on my friends s13

he
changed the rear brake pads
midway through the change, the piston fell out
when i changed mine, i was able to compress the piston by turning it clockwise

but it didnt work with this one
so he eventually tapped it back in and when he drove it that side stayed compressed and the pads just smoked

can anyone drop some hard education on our asses right now?

thanks

[SoguRacing]

the piston has seized or the internal components have seized. just get a new one. 80 bucks at autozone. mine started leaking and had no choice but to buy a new one. they're not rebuildable.

[dino6192]

the O rings that hold it in are though! the o rings are $5 from autozone and are very easy to replace.