Carsy

The car has done 50,000 km & the front rotors have worn from 28mm to 27 mm . The thickness limit before change out is 26 mm.

What has baffled me is that the average pad wear on both fronts is just above 1 mm also. ie just below 12 mm from original 13 mm.

So my pads are wearing almost at the same mm rate as my rotors.

From this forum I read that we can expect 2 pad changes for one rotor change. This obviously will not happen . I will be changing my rotors with about 10.5 mm still left on my pads

I am a conservative country driver.

I would be pleased to hear any feed back & recomendations.

JC

keith100

Hi Carsy

The way I read your post the pads are wearing twice as fast as the rotor.

ie 1 mm from the pads on each side of the caliper, but only 0.5mm from each side of the rotor?

But could be reading it wrong

hth

Carsy

Keith , you are correct .But I still can expect 2 pad changes for one rotor change.

Any explanation?

acr2001

I'm not sure what rate of wear is 'correct' for MB rotors, but I've always been told that they are made of a very soft material for better performance at the expense of longevity.

On my W203 I attempted to replace my half-worn OEM pads (had about 24k on them) with new pads - keeping the old rotors. It was no good - the rotors were very worn, and at an angle no less which matched the wear of the factory pads. New pads without that same angle didn't "match" to the rotors and were useless. Had to either replace everything or re-install the original pads. Ever since I have always been of the belief that new pads = new rotors on an MB for best performance.

dansonchan

I went to mb couple weeks ago! And they server man said its normal and rotors should be change with brake pad!!! it cost $600 something

Carsy

ACR2001 , Thanks for the good advice.

These rotors are in perfect condition. Braking is super smooth with lots of feel. Absolutely no sign of judder.

They will do for a another few years so will change out the hole shibang then.

Carsy

Rear Rotor wear is similar to fronts for 50,000 km.

Original 10 mm.Rotor

Now 9 mm.

Low limit 8.3mm

Pads .

Original 12 mm .

Now 10 mm.

If the present wear rate continues I will have worn out the rear rotors when the pads still have 8.5 mm left!

I have never experienced this before.

I was wondering ,seeing that I have no reason to use the brakes heavily & constantly ( county driving) , whether the pads accumulate a hard surface when being used lightly & this hard surface adds excess wear to the rotors ?.

Ausmbtech

Pad and rotor wear isn't a constant thing. Hard braking tends to wear the pads whilst minor pedal pressure tends to result in higher rotor wear.Not sure of the exact science behind it, it's just how it is. It's different for everyone.

Some of my cars need rotors every pad change, others get 2-3 pad changes.

Petje

By my prev C , replaced my front pads at around 40000km and the discs arent replaced, but think they need to be replaced at 80000 km.

kevink2

My general experiences: when Racing my 7 at HPDE's, my Porterfield race pads woud grind into the wearing rotor ... as it looked like an old LP record. A fellow racer had Peformance race pads that just buffed the rotors shiny, with tiny micro cracks on the rotor surface.

Dealing with "PBR" low dust pads on other cars, the MetalMasters would eat the rotors, while the Deluxe pads showed easy wear on the rotors.

Point is rotor wear can vary in the Industry, and observed wear in this is very helpful.


.

Carsy

Ausmbtech,

Thanks for your thoughts. It would be interesting to know about the science .

I suppose once you know about your driving style/ pad rotor wear you might be able to compensate by buying differing pad hardnesses.

Do you know of a softer pad that would suit me next time.?

JC

Carsy

Thankyou all for your imput . Its been helpful. JC

Ausmbtech

I'm not as knowledgable on this but I'll explain what I learnt when I was having trouble with trackday pads.

I was having trouble with overheating pads even thought they were very hi temp pads. It was explained to me that the issue was that the compound was based on generating high friction hence the high temps. It was suggested I used a different brand/compound that was designed more around adheasion rather than friction Yes, I was confused too.

Basicly the pad puts down a layer on the rotor as it beds in. This layer, when hot, adheres the the pad hence giving braking torque. pads wear, rotors have little wear. down side is that when cold they revert to mostly friction to give the braking torque so they actually wear the rotors faster as a daily drive then they do when on the track! When hot and using the adheasion they dont generate as much heat so in my case brake rotor temps dropped 150C by just changing the pads!!!!

I'm sure there is a better way to explain it but you get the idea how rotor wear isn't a constant. Ever seen a race car with big lips on the rotors?

LandSeaAir

Makes sense but when we did the brakes on my dad's S we just did the pads, although the pattern wasn't the same, the pads would form to the rotor within a week of full time driving (according to my dad whose been doing it for years). If the rotors are really worn however than yeah replace them, but if they're still good I wouldn't replace them just to start with a new pattern.

Wchomak