You have to adjust the e brake cable from below. I powdercoated my calipers this winter, and after re-assembling the calipers my e brake doesn't work very well. I've been adjusting the cable tension to see if it helps, and so far a no-go. I probably mucked something up in the rear caliper. It's such a PITA tearing the rear on apart, I may just go with no e brake.
I had my calipers powdercoated winter before last. When they reassembled the rear caliper they bent a clip for the ebrake. It would work once or twice and them pop loose and not engage. Unfortunately caliper parts are not available. I was able to locate a rear brake caliper from someone who put on big brakes and I took that to a local brake shop that specializes in rebuilds. They swapped out the parts and it has worked fine ever since.