I have a 04 A8L that needs 4 new sets of pads in the very near future. The shop I use and bought the car from is telling me that they need to replace the rotors at the same time. As of now I have yet to receive an answer as to why they would need to do this when I'm not grinding at all, this raises my suspicions somewhat. Although I have been happy with their work to this point.
My question is; Is there a good reason I would want to replace the rotors at the same time I replace the pads?

 

Interesting question, I have seen the same said here and there, but in my history of doing my own brakes on several different cars have never replaced rotors unless they are damaged. I'll be interested to see the answers here.

 

From my experience, even though I am very young, and do not know much. Usually when replacing brakes they replace the brakes then clean up the rotors. My father recently took his 04' accord to the honda dealer to have new brakes put on because it was shaking while stopping. Usually they can "cut" them or rotate them. This is done twice and on the third time the rotors will be replaced. This is caused from rubbing so much on one point, you turn them to extend the life, and then have no more room or the rotor may be too thin or unsafe to use so you replace them. Just get a second look from another mechanic, just say hey take a quick look.
Hope it helps!

 

That shaking is caused by warped rotors, a perfect example of when you do have to replace rotors, but in my way of thinking, if they're not shaking or vibrating, why would they need replacing?

 

I would have to agree with Bozee and Mongo18. The rotors of today are not the rotors of our fathers old cars. They are thinner and lighter to help in performance. This also means that we have to replace them more often. This is what we pay for with performance.

 

I am not sure about an Audi but I can speak about my Mercedes experience. I have an older S class Mercedes. 99% of the place that I go to will NOT turn a Mercedes rotor, at all.

 

Again, that's assuming they're warped or damaged. Say you've got perfectly round smooth discs, just worn pads. Why would you replace the rotors as well?

 

Rule of thumb is every time you replace pads you should have the discs resurfaced or replaced. However, if I know the rotors are NOT warped and the pads just low I will replace just the pads. I have done it a few times in a pinch and everything was fine.

 

Like I said, I've done a lot of brakes on a lot of different cars and only once replaced rotors, and that was because the rotors on my jeep were horribly warped. Replacing perfectly good rotors seems pointless to me.

 

That's a STUPID rule. "Resurfacing" is simply GRINDING material away from the rotors. NOT WHAT YOU WANT TO DO!!! If your rotors are warped (easily demonstrated with the proper tools, at a reputable shop), REPLACE THEM!!!

Understand: Brakes WORK by EXCHANGING motion for heat. Panic stops can and often do warp rotors, especially cold rotors, by putting too much heat into one section of the rotor, too fast. Grinding down the whole thing, just to take out the wobble means there is LESS metal to absorb and exchange heat with the outside air, the next time you may have to panic stop. More wobble. More metal to grind away. MORE CHANCE OF A CATASTROPHIC FAILURE when you NEED them to work at peak efficiency.

Spread the word! Tell your friends, to, too!! NEVER RESURFACE YOUR ROTORS!!! It just guarantees MORE brake work for the shop, when you do.

@ Mongol:
Rotors wear, from use. Just like times. Just like EVERYTHING in and on a car. Replacing used parts extends the life of the vehicle, and yours, believe it or not. $125.00/axle, or less for new rotors, every 2 years, or so, is cheaper than raised premiums, and much, much cheaper than reconstructive maxio-facial surgery.

Any decent shop will know what the requirements are for material/rotor-wear, for your area. They will also be happy to show you if YOUR rotors are safe, warped, or below the wear limit. You do not have to take their word for it. If they don't, won't, or can't show you the law, AND your rotors failure with a proper caliper measurement, take it to someone who will.