Do your diagnosis by dividing the system into sub-sections.
I would suggest these three main areas:
a. pedal return.
Does the e-brake come off if you manually lift the pedal? CAN you manually lift the pedal?
b. cables free and properly adjusted?
You stated new cables, but are you sure the cables are routed properly, free from pinches and kinks, and adjusted correctly? If disconnected from the pedal and brake shoe lever ends, do the cables move freely?
c. shoe levers and related hardware in order?
What's going on under the drums? Are you positive everything is installed correctly and adjusted properly?
