Loosen the cable by the handle. I had a buddy do a rear disk swap on his EK hatch and he kept tightening and tightening the adjuster by the brake handle and it was at a point that when the parking brake handle was lowered, it didn't slacken the cable enough for the caliper to really relax and reset. It's hard to explain but I backed the adjuster back till the bolt was almost flush with the end of the adjustment stud, pumped the brake pedal a few times and the parking brake worked just fine after that. You might have the same problem he did so give it a try.