[KBM5]

Hello Guys,

So today I was about to go on a drive with my 2018 F90 M5 and a noticed something unusual on my driver side Ceramic Break Rotor. I had a closer look and it looked like a piece of my rotor just fell off and left a hole (look at the pictures attached).

My car has 23,000 Kms on it, I maintain extremely well, I'm extremely cautious with it. The car has been tracked once in its life about a year and a half ago, I also often go for spirited drives, and the car is winter driven as well in Montreal QC, where it gets VERY cold. When I do use my breaks hard, I do give them a cool off period of at least 3-5 minutes of slow driving to air off the heat from the disks before completely stopping, and make sure I do not over heat my rotors. I use the car how it is meant to be used, mostly on highways for speed runs and or twisty roads a times, but again never abusing my breaks. Again I'm very cautious.

Therefore I have the following questions:

I was wondering what could've caused such an issue?

Is this something that can be covered under the warranty?

Can I still drive the car in the mean time? How safe is it?


Thank you guys for any help or insight you have on this issue!

[Alberta]

I would insist for the warranty to take care of it.

This is absolutely not normal, especially with a low mileage.

I also have CCBs on my M5 with 32 000km (never tracked), and my rotors are in perfect condition.

[Demon Barber]

I have CCBs and I've worried about this scenario happening. It's really difficult to know how any particular dealership will deal with this as far as warranty coverage due to the price of these rotors and uncertainty of damage versus manufacturing defects, but I would approach them with a calm and confident case that this looks like focal delamination due to a weak point created while the rotor was made. The problem is that these rotors are so hard but simultaneously so brittle that a rock hitting the rotor just right could conceivably do this kind of damage as well. Hopefully they will offer a good faith replacement under warranty if you have a good relationship with your dealership and approach them the right way.

It's probably driveable to the dealership, but I wouldn't use as my daily driver until the rotor is replaced.

Please keep us updated through this process, as many of us with CCBs will learn something from it.

[onfireX5]

Originally Posted by Demon Barber

I have CCBs and I've worried about this scenario happening. It's really difficult to know how any particular dealership will deal with this as far as warranty coverage due to the price of these rotors and uncertainty of damage versus manufacturing defects, but I would approach them with a calm and confident case that this looks like focal delamination due to a weak point created while the rotor was made. The problem is that these rotors are so hard but simultaneously so brittle that a rock hitting the rotor just right could conceivably do this kind of damage as well. Hopefully they will offer a good faith replacement under warranty if you have a good relationship with your dealership and approach them the right way.

It's probably driveable to the dealership, but I wouldn't use as my daily driver until the rotor is replaced.

Please keep us updated through this process, as many of us with CCBs will learn something from it.

Agreed. Once a failure begins, it could come apart.

[TrevorM3]

wow, i've literally never seen this happen before. On any car forum. I'd be curious as to how bmw will handle it. I wouldn't drive it. Only place you need to go is the dealer, please keep us posted.

[KBM5]

Originally Posted by Can-am

I would insist for the warranty to take care of it.

This is absolutely not normal, especially with a low mileage.

I also have CCBs on my M5 with 32 000km (never tracked), and my rotors are in perfect condition.

Thank you for your reply! Yes definitely. I'm a little worried but hopefully, the dealership would be willing to change it.

Would you mind posting a close up picture of your brake disk so I could compare what mine look live vs 32K Kms car?

Thank you again!

[KBM5]

Originally Posted by Demon Barber

I have CCBs and I've worried about this scenario happening. It's really difficult to know how any particular dealership will deal with this as far as warranty coverage due to the price of these rotors and uncertainty of damage versus manufacturing defects, but I would approach them with a calm and confident case that this looks like focal delamination due to a weak point created while the rotor was made. The problem is that these rotors are so hard but simultaneously so brittle that a rock hitting the rotor just right could conceivably do this kind of damage as well. Hopefully they will offer a good faith replacement under warranty if you have a good relationship with your dealership and approach them the right way.

It's probably driveable to the dealership, but I wouldn't use as my daily driver until the rotor is replaced.

Please keep us updated through this process, as many of us with CCBs will learn something from it.

Very much agreed! Thanks for the reply. I just hope the dealership dosent go the "wear and tear" route. I was just wondering aren't these disks supposed to have a lifetime warranty?

[TrevorM3]

ceramics aren't covered by warranty.


but this case looks to be an exception

[2021M5C]

In EU, Latvia, dealership covers CB on f10 m5. It happened three times already.

[gblansten]

I was going to brake in hear and say that isn’t a break rotor. But, I saw your pic and sorry. Hope you get that corrected under warranty.

[Demon Barber]

Originally Posted by KBM5

Very much agreed! Thanks for the reply. I just hope the dealership dosent go the "wear and tear" route. I was just wondering aren't these disks supposed to have a lifetime warranty?

Definitely no lifetime warranty on any consumables, which includes iron and ceramic rotors. Ceramics do last much longer than steel, but can still be exhausted.

Regarding your comparison pic request, unless chunks are missing like yours, a brand new rotor and one at the end of its service life will look about the same. They don't wear on the surface like an iron rotor, and don't become thinner. They lose mass/become lighter as they wear out due to the carbon oxidizing with repetitive heat. They essentially slowly burn internally as they are used, and weigh less and less. In fact, the starting and minimum weights are printed on the hat of each individual rotor by Brembo, so as long as your dealership has an accurate scale for weighing CCBs, your damaged rotor should weigh within spec, which would give you a strong case for claiming premature failure. I'd make damn sure that scale is calibrated before suggesting this experiment, as a false high reading kills your argument.

[dardeca]

The whole point of purchasing CCB is to take the add'l "abuse" of high heat from tracking the car, etc. So for BMW or the dealer to deny warranty on these b/c you used the brakes as intended would be ridiculous.

[Neptune7]

I was thinking of ceramics for the next car but am going to see how this thread plays out - BMW should take this very seriously.

[mjr24]

Personally I would leave out that you ever tracked it when you talk to them.....

It has nothing to do with why this happened so I just think it does nothing positive to mention this to the dealer. They might take anything they can to get out of paying. Why risk it? You want to get this taken care of as quickly and easily as possible.

[TheRealBob]

The wear indicator on the rotor clearly indicates heavy usage. It would very much surprise me to see BMW replace this for free. In fact, if the other rotors are equally as worn, they will need replacement as well.

Technical information on CCB's - https://documentcloud.adobe.com/link...2b10&pageNum=1

[onfireX5]

Originally Posted by TheRealBob

The wear indicator on the rotor clearly indicates heavy usage. It would very much surprise me to see BMW replace this for free. In fact, if the other rotors are equally as worn, they will need replacement as well.

Technical information on CCB's - https://documentcloud.adobe.com/link...2b10&pageNum=1

Great link ! Looking at the linked pics, it appears the Circle coating has To be worn off completely and some laminate erosion within the circle to determine % wear. He still has some circle coating left and all laminate.....I could be looking at the pics wrong though....???

[euro*]

Originally Posted by TheRealBob

The wear indicator on the rotor clearly indicates heavy usage. It would very much surprise me to see BMW replace this for free. In fact, if the other rotors are equally as worn, they will need replacement as well.

Technical information on CCB's - https://documentcloud.adobe.com/link...&pageNum=1

Thank you for this link, very helpful !!

Looks like OP is out of luck, and rotors are due for replacement anyways...

[JOHNBMWM5]

The OP will get nothing for those disks they are well worn, sorry expensive cost coming your way.

[onfireX5]

If this is partial wear.....and ok to run....

[onfireX5]

And this is greater than 50% wear and should be replaced....

[onfireX5]

This has not even removed the top coat yet to start delamination and should be fine to drive.....if it had not "chunked" elsewhere,,,

Unless that wear is deeper than the pic. If it’s into the rotor, then yep, they are used up.

[GhostOne_322]

Originally Posted by KBM5

Hello Guys,

So today I was about to go on a drive with my 2018 F90 M5 and a noticed something unusual on my driver side Ceramic Break Rotor. I had a closer look and it looked like a piece of my rotor just fell off and left a hole (look at the pictures attached).

My car has 23,000 Kms on it, I maintain extremely well, I'm extremely cautious with it. The car has been tracked once in its life about a year and a half ago, I also often go for spirited drives, and the car is winter driven as well in Montreal QC, where it gets VERY cold. When I do use my breaks hard, I do give them a cool off period of at least 3-5 minutes of slow driving to air off the heat from the disks before completely stopping, and make sure I do not over heat my rotors. I use the car how it is meant to be used, mostly on highways for speed runs and or twisty roads a times, but again never abusing my breaks. Again I'm very cautious.

Therefore I have the following questions:

I was wondering what could've caused such an issue?

Is this something that can be covered under the warranty?

Can I still drive the car in the mean time? How safe is it?


Thank you guys for any help or insight you have on this issue!

Any notable wheel damage?