the brake is on the right side of the rearend just inside the frame. Usually it takes a 7/16 or 1/2" wrench to adjust it. Clockwise will make it work if all the parts work. You may need to disassemble the brake and clean the push pins if they are rusted and can't move. It's easy just take it off and disassemble, clean and put some antisease on the push pins.
John F. Fitzsimmons, February 2008