Brake piston too tight?

[cwiert]

so i changed my rear pads and like many, i couldn't get the pads to fit right. so i did the C-clamp trick, and that only moved the piston a little (and this is with the parking brake bolt off). I had to use a hammer to bang the piston all the way back. is that normal????? should it move more freely than that?
i ask because i got the new pads on, but the brakes still suk. i bled them and bled them some more, and now i see fluid dripping when i press the brakes. what did i break now?

[cdalejef]

you should loosen the mastercylinder cap when pressing the piston in. You probally blew a seal.

[400exdad]

You probably also needed to loosen the parking brake adjustment bolt too... Better yet, take it off and get a good blocking plate... some are too shallow and can cause the same problem... I know for experience.