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JRE320
12-15-2003, 09:37 PM
Can you re-surfaced a cross drilled rotors? :confused:

moebiusgold
12-15-2003, 09:52 PM
Yep, any good brake shop ought to be able and do it. Save some bucks and give them just the rotors. Get estimates first and obviuosly tell them what you have. A cheap brake lathe will do a poor job. Find out what equipment they have. I personally don't bother unless there is a pulsing. I run rotors until I get scared of how thin they are ( obviuosly not with min. thickness pads) but then I look at my tires and rotors almost every day that I drive. There will be surface cracks way before they want to come apart.

BoominVolvo
12-16-2003, 12:17 AM
I wouldn't recommend turning any rotors honestly. They were a certain thickness for a reason plus some safety factor. You are eliminating the safety factor when you turn them. Especially with cross-drilled rotors (as opposed to cross-cast) which have a tendency to crack anyway, turning them won't help. I would recommend getting new ones if possible!

Martin

Eurosport
12-16-2003, 08:35 AM
i'd get new ones, they are not that expensive
and no matter how good a brake shop is, they probably won't come perfect

CKlasse
12-16-2003, 02:07 PM
I have machined drilled rotors before. They aren't that hard. Ask them to do it 1000-2000 at a time instead of 3000/4000 and not to go beyond the minimum recommended thickness.

JRE320
12-16-2003, 03:31 PM
I'm thinking how in the hell will they rotate my rotors? It's not like the stock one where there's no drilled holes. Ummmm... I 'm afraid that they would messed up my rotors. :rolleyes: :(

moebiusgold
12-16-2003, 07:09 PM
Originally posted by CKlasse
I have machined drilled rotors before. They aren't that hard. Ask them to do it 1000-2000 at a time instead of 3000/4000 and not to go beyond the minimum recommended thickness.
I think Cklasse means .001" to .002" at a cut. Make them put in a new carbide insert while you're at it. I'll side with Eurosport. I run them till I can't stand looking at them and just buy new ones. They are cheap in the big picture. I've only actually turned one pair and they were brand new (not on a MB) and one had .003" runout. :(

CKlasse
12-16-2003, 09:00 PM
Originally posted by moebiusgold
I think Cklasse means .001" to .002" at a cut.

:D yes, thanks for clarifying. I simply go with the digits on this machine :)

PS... Why do you need to MACHINE your rotors? Is it warped? out of round?

JRE320
12-17-2003, 09:38 AM
I was wondering how you could rotate the cross drilled rotors and eventually my rotors are not perfectly smooth. That's why I'm asking your opinion. ;)

moebiusgold
12-17-2003, 09:18 PM
Originally posted by JRE320
I was wondering how you could rotate the cross drilled rotors and eventually my rotors are not perfectly smooth. That's why I'm asking your opinion. ;)

I would never rotate a rotor (L to R). I know groves don't look cool, but if you use your brakes hard, that is going to happen with any setup sooner or later. My Old benz rotors would get flatter when I put new pads on.:D

omegabenz
12-30-2003, 05:18 PM
In my experiences if a rotor warps, re cutting it will just make it warp more. It's a waste of time especially on a car that can do 140mph you know what I mean.

There was a big discussion on mercedesshop.com on cross drilled rotors with porterfield brake pads. Porterfield claims their compound does not need holes to move the gas out of the contact area of the pad. Also brakes work better when the pad can touch the most rotor, so holes reduce the surface contact area of the pad.

Also I have heard, but I dont know if it is true, slotted rotors are said to wear down the pads fast because they are like a rotating knife. It kind of makes sense, but I already put them on my brothers 300D turbo. But if water gets on the rotor, drilled and slotted I think would make a benifit.

I also have "perforated" rotors, made by Zimmermann for my 560SEL brakes. Cast holes are far better than drilled. Cast holes align the "fibers" of the metal, making the hole much stronger and less prone to cracking.

I hope this has helped you.

Also, I have been working on a porterfield group buy for a while, do you think you guys at 202 would like to get involved? I posted it at bnzsport and mercedesshop a while back.