I have a macomber 20 harness B-4 loom which I purchased used. I have a warp on the back beam, and when I push on the brake release (front right), the beam does not release as it should, so I cannot advance the warp without going to the back and while depressing the front break (quite a stretch) manually move the beam. I've included pictures. I do not know if the cable is wound properly on the back beam or if something is too tight, so I don't know what to do to solve the issue. MAC whisperers...any help to solve would be appreciated!