I purchased a 91 C1500 a short time ago and have been working on getting it into shape. I backed out of the garage today and one of the rear brakes locked up on the snow, without even touching the brake pedal. I pulled forward and continued to back up without any more trouble. I pulled the rear drums and everything looked okay. Has anyone experienced this. Do these trucks have the long shoe and short shoe like the old chevs had. If so, this truck does not have a short shoe. Any input would help. thanx. wnk.