There are two conflicting points of view on this issue. Some
manufacturers say it is not necessary because their drums and rotors
are finished at the factory and come ready to install. Resurfacing
is therefore totally unnecessary. Furthermore, it would reduce the
thickness of the drum and rotor and consequently its overall service
life.
Others say that in spite of what the drum and rotor manufacturers
say, new drums and rotors should always be turned to make sure they
are true and flat.
It is better for you and your customer to take a thin cut to make
sure everything is right rather than risk a comeback because of
noise or pedal pulsation.
