So I took my car through inspection and they told me that my right rear brake is not working as well as the left rear brake. This includes the parking brake. Recently I had a frozen parking brake line to the right rear I replaced as well as the parking brake handle/cable that I snapped trying to unfreeze the line. I also replaced the right rear caliper. Bled the brakes 4 times now with no improvement. All 4 calipers are getting pressure. Pads have plenty of life left on them but appear to have a little uneven wear. I just took the brakes apart and bled just the right rear. I noticed that the pin on the pad was not sitting in the slot on the piston so I readjusted but still didn't change anything. Could it be the piston getting stuck? It is brand new. I didn't compress it when I firstI am thinking of compressing it? Could it be the master cylinder? I would think if it was the master cylinder the left side would be weak as well.. Thoughts?