One of the biggest problems with CC brakes are what they call the sliders. This is the part that the cables hook on to at the rear brakes. They go through the backing plates and actually work the shoes. They are also tied into the self adjusters. What tends to happen is that the lever the goes through the backing plate will become stuck. Pull the wheels and drums off the rear end. It is much easier to do the rest if you unhook the bottom spring and take the star gear out of the way. Then hit those puppies with a bunch of brake cleaner and compressed air. You need those sliders to move back and forth as freely as possible. Once you get them good and clean use some type of dry film lube to keep them sliding free and most if not all your bake problems will go away.