I noticed that my drivers rear brake was sticking a while back. It seemed to drag a bit since the day I built it. One day it was so bad it was steering the car and smoking. Being from California, I'm not a big fan of smoking. I thought it was the piston getting locked. But it only happened after I had the ebrake on. FFR sent me a new caliper and I put it on. Same problem. After testing everything including the cable, lever, etc, it appears that the spring end was getting hung up on the caliper. Or, the actuator lever needed some alignment. The tolerance was very tight. I just used a screwdriver to pry it down a bit and it releases perfectly now. I wouldn't normally mention it but since it did the same thing on two new calipers I'd figure it's important. Might be a batch of them that have this problem. I've notified FFR.