What is the maximum safe thickness when turning rotors for a 2003 C32 front rotors and a C320 Coupe rear rotors? I've heard a lot of conflicting information about turning rotors on MBs. Never had an issue with it on Japanese or domestic cars. Need to do something this weekend.

I think it should say right on the rotor if I'm not mistaking, at least the rotors I've turned.

I Would Recommend NOT to Turn/Machine the Rotors...When I Worked for Mercedes They Did NOT Allow that...Just replace If Worn/Lip OR Under Min Thickness...The Specs are on the Brake rotor

Just curious as to the rational for not turning them if they are not smaller than minimum thickness?

There's no reason to. Once new pads bed in, the little microridges acutally increase braking surface. If there are serious problems (warping or cracks) the rotor needs replacing. Plus, removing any metal reduces fade resistance.

Martin

Thanks for the info

The real reason is that the rotors are so inexpensive it's not worth the labor time to machine them.

This is what I was wondering. I can get them turned by a very experienced older guy (the only guy I let balance my tires) for 5.50 each. sure beats $125 each.

Once again, if they are not below thickness spec, not warped and not cracked, why would you replace them? I don't see how cost enters the picture. If they're in spec, just change the pads. If they're not, replace them. I honestly don't see a situation where you would machine them because of cost.

Never turn a Mercedes Benz rotor, they are throw aways. Most last over 100,000 miles with avg use. Just replace the pads. Conflicting reports that you are getting are not from Mercedes Benz. Turning rotors is a thing of the past(real old school) no up side to it, just throwing money away.

Your experience with Japanese and American cars has no relevance to Mercedes.

Wrong. Mercedes doesn't define automobiles, but they definitely influence.

Now I know why you don't turn them. The front rotors have about 30k miles. They were at 23.7 mm thick. Min turn is 28mm and throw away is 24mm. It's amazing how badly one set of pads chewed up the rotors. No real groves, just evenly ground down. I guess that is the price you pay for brakes that really work! The rear rotors with 46K miles where below min spec as well. Hopefully the Porterfield pads will go easier on the new rotors.

Interesting. I had a similar issue with a VW Golf. At the first pad replacement, the rotors were worn below the service limit. Thin rotors cost less and save unsprung weight, I guess, but it does seem pretty chintzy.