More often than not, many rotors today are being replaced when the brakes are relined - and some motorists are complaining that new rotors really aren't necessary. Resurfacing can usually restore the friction surface on worn rotors to like-new condition, unless a rotor is worn down too far to be safely resurfaced or has cracks, deep grooves, severe rusting, hard spots or other structural defects. So why are so many rotors being replaced? The answer, I think, is two-fold. Part of the answer has to do with customer satisfaction and reducing comebacks. Regardless of what a brake job ends up costing, the one thing you don't want is noisy brakes or a braking problem that results in a comeback and an unhappy customer. A comeback is work you have to do over (possibly at your own labor and expense), and an inconvenience for both you and your customer.

If rotors are not resurfaced properly or if the rotors have too much run-out, the customer is going to feel it every time he steps on the brake pedal. So that's one reason for replacing rotors. New rotors reduce the risk of improper surface finish and too much runout (at least in theory).

The second part of the answer involves money. The price of many aftermarket rotors has fallen drastically in recent years due to the availability of inexpensive offshore rotors. Quality remains an issue with some of these rotors, but the price is so attractive for some installers - especiall...