drwombat

I have about 55K on my car. My dealer tells me that typically the rotors wear down with pad usage (duh) and that, according to them you should replace the rotors when you replace front pads. Rears he says you can run two sets of pads before needing new rotors.

I'm worried they're just trying to rip me off, so I called an independent mechanic around the corner that I trust, and asked him how much to change pads. He told me he wouldn't change pads only because specs are to change pads and rotors and he doesn't want to be liable for not following spec.

What's the real deal?
I'm not opposed to getting new rotors, but I don't want to if I don't need to. I want new pads, though. Less dust, less squeal, all that.

markbradford

Any other reason is bull**** (unless they're cracked or something)

ex-quattro PETE

I've never had my pads nor rotors replaced under warranty (within the first 50K miles), but IIRC, most people that did, the dealer only replaced the pads and kept the old rotors because:

(a) the rotors were still within spec, and
(b) dealer/AoA did not want to pay for replacing the rotors.

As a matter of fact, most dealers will refuse to replace any part that is still within spec, under warranty.

But now, once you're no longer covered, they'd like you to replace every stinkin' thing, wouldn't they? ;-)

EDIT: By the way, I'm not saying that you don't need new rotors. You may actually need them if yours are worn out or worn unevenly (warped).

RKA

They are relating their experiences with you...but generally speaking, pads and rotors should be swapped together (which is what your mechanic is telling you).

The only way to find out for sure is to measure the rotor thickness, and compare to min and max spec. If the existing rotor thickness is less than halfway between min and max spec, that means you will most likely wear out the rotors before you wear through the next set of pads...and you should replace the rotors now, and be done with it. If your existing rotors are more than halfway between min and max spec, you've been kind to your rotors, and they will most likely be fine for the life of another set of pads. You may need to bet them machined to smooth them out, which will remove some material, so take that into account when evaluating the thickness.

nizmosx

turning down the rotors first for a flush fit.

RKA

So, no need to measure the rotor thickness and compare to manufacturer specs?

drwombat

And yes, by dealer does tend to be very honest. I have always felt like they told me things honestly, and they'd tell me to go elsewhere when their prices were bad, etc ...

Thanks for your opinion - knowledgeable as always!

Ritz

Even if you don't replace the rotors, you need to put them on a lathe and true them up.

RKA

I don't know that the manual lists a "max spec"...or new spec (what I meant to say). They probably only list a min spec, so you'll have to do some leg work to find the thickness of the rotor when new, then do the math to make a judgement call.

ex-quattro PETE

Front: new: 25mm, minimum: 23mm
Rear: new: 10mm, minimum: 8mm

This is for a quattro version A4 though. Not sure if the FWD had different size rotors or not.