13 Mini Hatchback R56 rear brakes dragging!

[Scott Causey]

While changing the struts and shocks on the wife's Mini, I found the rear brake pads were severely worn. The right rear inside pad was worn 2/3 more than the outside pad. The left rear was not as bad. I also found the brake booster hissing while pressing the brake pedal. So after changing the brake booster, booster vacuum pump, and all 4 brake hoses the dragging pads were a little better. So I've just changed both rear brake calipers and bled the system again. The left rear is a little better than before. The right rear is still way too tight. Oh the parking brake cable haven't been connected since I first started, so I know that is not a issue. Can anyone provide any help? I'm about to pull out what little hair I have left.

Thanks, Scott