Ive changed everything back to the rear calipers including brake cables, hardware, and the parking brake handle itself and still no luck. I'm guessing that it might be a frozen caliper, but that doesn't really make sense to me since neither side locks up but yet both wheels lock when the foot brake is applied. I've tried to do the auto adjustment where you engage the park brake and drive a few meters in reverse but to no avail. Also tightening the bolt for the cable tensioner helps nothing, even at maximum tension. My last guess would be the calipers themselves but as of now I am stumped. Any help is greatly appreciated.