[Joyridin]

Blowing air int he banjo bolt will not make the piston move far if it is all the way back. Did you try moving the e-brake lever back and forth to "ratchet" the piston out? The piston is set-up on a ratchet mechanism. When you pull the e-brake, the piston ratchets out without rotating. You may have to do it quite a few times to get it out a bit.