i have a 94 del sol S disk in front drums in rear. when i step on the brake lightly i can hear something grinding.. sounds like from the rear drums. but thing is i noticed it last winter and was going to fix it over summer.. didnt hear it even again after it heated above 50 degrees.. but then it came back this winter.. so i have no clue.. i was thinking shoes wore down? but why would it only do it in the winter?