It depends on the amount of oversize, or out of round of the particular drum. When radius-grinding the linings was a common procedure, we would grind the linings to a slightly smaller radius than the drum so the center would contact first, and when the pressure of the shoes against the drum would push it into an oval shape, there would be full contact with the lining. Otherwise, there would be toe and heel contact only. Since the tree huggers will give anyone who dares to grind a brake lining 30 days in the electric chair these days, sanding the linings into full contact is about the only option left to anyone who wants to do a good brake job. The sandpaper creates a slightly smaller radius anyway, so the result is about the same.
Jerry
