my rear brake will not let go of the wheels when i release the lever... i've changed both housing and wires on the front and rear... the front is fine... i've disassembled the rear caliper and adjusted the pivots many times... still can't get the "sticky" brakes to disengage... does it sound like my dual pivot is toast if there's such a thing? tia

Sounds like the springs are gone. You could get a replacement, possibly. Ask your LBS.

What kind of brake?