Dumb Brake Question

Hey guys,

I've got some 11" rear brakes here and the shoe measures 2" of braking surface. Would the drums be the 2" drums or would they be the 2.5". How are they measured? Is it by pad width or braking surface on the drum?

Thanks!
Paul

I always thought it was the friction pad dimension. That is how we used to check them at auto parts store.