mmgrad

Ok, I know the recommended minimum rotor thickness is stamped on the rotor itself, but, thats just MB wanting to make tons more money & covering their ASSets in case a thinner rating causes immediate danger to the driver/passengers

So, for instance...
W203 C320 new rotor is 28mm thick, and minimum safe thickness is 25.4mm
W203 C32 new rotor is 30mm thick, and minimum safe thickness is 28.0mm

I'm sure the pattern goes the same across other models... So the question is, how long do you guys run with your rotors before you swap them out for new ones?

With these factory rated minimums, you pretty much need to change the rotors EACH & EVERY TIME you change the pads...

Bagher

haha that is why MB doesn't recommend turning rotors, they want you to buy a new set of rotors for every brake job!

E55AMG99

I guess the material really contributes to improved braking. Too bad they are so damn expensive

Josh K

Just watch them carefully. Once they crack - that's too thin ;0)

mmgrad

haha... well, my intentions is not to wait until it starts cracking... just want to know when everyone else decided to ignore MB recommendations and change it OUTSIDE of every brake pad change... ie., what mileage or after how many pad changes?

Josh K

I know bro, I was messin with ya ;0)

x15jq

i replaced the fronts after the first pad change, but the rears i threw up another set of pads and i have had absolutely no problems.

viguera

If it was up to MB, I'd be on my 11th set by now... every time they see the damn things they recommend that I changed both pads and rotors.

And that's before the sensor trips... WTF?

I never follow their recommendations anymore... I go by mileage and feel. By now I know the car well enough to know when it's time for things to get done...

mmgrad

So, what is your mileage recommendation? 60k? 90k?

viguera

Hell no... the OEM ones don't last me more than 30k. But I drive... aggressively.

E55AMG99

MB doesn't recommend changing rotors with every pad change. They measure the thickness and if it does not meet spec, they replace. However, MB front rotors almost always need to be replaced with the pads every time!

I don't think it matters how hard you drive. My mother-in-law drives very conservatively and although her front pads in her CLK lasted well over 50K, the rotors still had to be replaced. My CLK only got 30K before pads and rotors were needed up front.

On the other hand, how many of us went into the shop with a dial caliper to see the thickness for ourselves? Maybe it is a conspiracy to get us to spend more money on repairs.

x15jq

well, when i did my front brake job, i replaced the rotors with brembo ones. Im almost due for pads again, and the brembos barely have any visible lip like the oe ones did, so i dont think they wore much at all. Maybe they are not as soft? I definately dont plan on changing them when pads are due because of this.

E55AMG99

Cool! I'd love to hear how much theyv'e worn when you go for the pads. Keep us posted, please.

ima55r2

If you don't have calipers to measure them, the old rule of thumb for changing out rotors is the lip showing wear about the thickness of a dime.

mmgrad

so, in other words, ya'll follow the minimum spec stamped on the rotors... once you hit that threshold, you just change it?

but seriously, from new to replace, 2mm isn't very much at all... is 30mm THAT much safe than 28mm?

many people shave their rotors... how is it any different for a MB?

Maybe its time to invest in some zimmerman or brembo rotors, which 'may' have a little more longevity...

E55AMG99

Hey Danny,
I agree that 3mm isn't very much tolerance but I'm too chicken to find out exactly how thin we can push the rotors before they overheat and break apart! US cars and trucks have much thicker rotors and wider operating range. They are designed to be cut with each pad change. MB rotors don't have the extra "meat"!

I'm curious too about aftermarket rotors. Good luck,
Greg

mmgrad

Hey Josh... Need you & all the folks with high mileage CLKs to chime in...

Since you guys have obviously gone through several pad changes... how frequently do you change the rotors?

viguera

I'm in an 02 with 90k. Third set of front pads, second set of rears. The fronts will have to go in a few weeks though, I can tell...

But I do a ton of city driving, so it's stop & go all the time.

mmgrad

so you are still on your first set of rotors? thats impressive...

have you noticed any signs of fade under heavy breaking?

viguera

I noticed I typed that wrong... it's 3rd set of fronts, as in rotors.

So they're basically lasting me around 25-30k... and when they're changed, you can tell that they're due...

JMA

I have an '01 with 77K and just replaced my front rotors for the second time (and pads for the third). The last time I had pads changed, the dealer actually let me slide on the front rotors.