[TJ]

It sounds like everything was fine with the system for about one year. Have you turned the drums beyond the recommended specs? I recently went through a similar problem. When I pulled the drums I found that the shoes were slipping off the raised area of the backing plates when the brakes were applied and were hanging up on the drum. I found that someone had turned the drums too far which allowed the shoes to go out to far to make contact. Drove me crazy for two weeks until I looked at the adjusters and could see they were adjusted out almost all the way. Bought new drums and it solved the problem. Check your backing plates and see if they are hanging up. You can see clean metal on the outer edges of the raised areas on the plate if they are hanging up.