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      05-19-2020, 01:28 AM   #7
brad850csi
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Drives: 16 F13 M6 Comp
Join Date: Jan 2015
Location: Auckland, New Zealand

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Quote:
Originally Posted by Flying Ace View Post
To expand on Brad's comment here....

Pads are just one wear item and the computer indicator from the brake pad sensor is an estimate. A very good estimate based on my decades of BMW ownership, but still an estimate.

Your brakes likely will need changing based on those indicators.

To answer your question, dealers check the computer, and they perform a pad thickness measurement.

Now rotors is a whole different story. CCB rotors need to be weighed. You should not balk at the cost associated with dismounting each rotor to weigh them, but considering a whole set is $10,000, it's little money spent to gauge how much more life you have left. CCB's have relatively huge variability in manufactured weight, which means each rotor begins in life with a different weight. Also the precision involved in measuring the weight is very minute. So each one technically should be cleaned before weighing.

There is a visual indicator for rough estimate on the rotors. They are little dime sized circles etched into the rotor. When those circles become non-circles, that indicates the rotors wearing down towards the end of life.

The only way that I'm aware of that that you can measure rotor weight without taking the rotor off is with the carboteq tool.

https://www.proceq.com/product/carbo...c-brake-discs/



Most independent Porsche shops should have these laying around. You should take your car to these shops and pay them for a half hour of their time for using their tool. If you feel like your trajectory of ownership will be owning CCB equipped cars, you can probably just buy the tool out right. Pretty much all modern day exotics, and many mid tier Porsche models come with CCBs. Save you a lot of money over time.

Google BMW CCB rotor wear indicator and you'll see a BMW manual out there that shows you what to look for on the rotor. It's also in the video I posted above. There's still a minimum rotor thickness measure, but it's a high precision measurement, that requires calibrated tools.

Lastly there's a theory out there among CCB owners across all manufacturers that you should change your pads halfway through their life anyways. It somehow extends the longevity of your rotors. Don't ask me why, I haven't had time to pour through the forums discussing this topic and rationale.
Lol thanks - a friend had just left after coming around to my place to celebrate NZ going back to being fairly open and I had quite a bit to drink, that was as many words as I could string together!

I'm now sober and did some searching Lemetier is amazing, check out his post in this thread specifically #63

https://f80.bimmerpost.com/forums/sh...1302752&page=3
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