[m.dreamin]

This is the first car I've had with CCBs so I'm not sure if the sound I'm hearing is normal. I'm about 6K miles in and occasionally the brakes have a hum as I come to a stop. I have read that CCBs will "squeak" when they're cold or wet, but "squeak" to me makes me think of the high-pitched metal on metal noise like when brake pads are thin and the metal wear tab is meeting the rotors.

The hum usually occurs when the air temp is cold, and it usually only happens at lower speeds, such as 35 mph or lower. That said, it did occur the other day as I came to a stop at an intersection when the air temp was 80 degrees.

Here's a video to demonstrate the sound. I'm not sure if it needs to be seen by BMW and so would appreciate any insight or experience with CCBs.

[NightWriter]

Yeah, that's still a brake squeal. 95% certain that's normal, especially if the noise dissipates once they warm up (rotor temps, not ambient).

[Likeanowl]

Yup, had the exact same sound among many different others on my F80’s CCB’s. Biggest reason I absolutely do not miss them one bit. In the summer they’d squeal so loud that on several occasions people on the street would turn at stare at me. Never ever ever will go back to CCB’s again.

[m.dreamin]

Originally Posted by Likeanowl

Yup, had the exact same sound among many different others on my F80’s CCB’s. Biggest reason I absolutely do not miss them one bit. In the summer they’d squeal so loud that on several occasions people on the street would turn at stare at me. Never ever ever will go back to CCB’s again.

Good to know. Also surprising that they'd make noises in the summer. I took delivery in August and never heard this hum sound, but I suppose it takes time for the pads and rotors to settle in together, which I'm guessing is what happened to mine.

It's definitely not ideal and sometimes is a jarring sound, but for now I'm not having to deal with the massive brake dust issues I had with my F82. I can't stand dirty wheels, and yet I couldn't keep up with the dust from the M compound brakes.

Given these brakes are massively expensive, my fear was that this sound was something ominous.

[Limegrntaln]

Mike, gimme the keys on the next get together. I'll make sure they don't make noise, for you. It may include a few stops from 100-120 to near stopped, but we will get it taken care of.

On a side note, if you have a pressure washer, give the rotors a good spray down, to get any loose contaminants out of the holes of the rotors. That noise you're hearing is fine glazing that you're getting between the rotors and the pads. You're getting that perfect resonance, like you would get if you were sliding a piece of furniture across a wooden floor, or pulling a chair out, to sit on. Same Noise.

You need to take them out, and knock the stank off of them, a little. If they ever start making this noise, steel or CCBs, you're not hard enough on the brakes. You gotta get out of Miss Daisy mode, and get on them, a little.

[m.dreamin]

Originally Posted by Limegrntaln

Mike, gimme the keys on the next get together. I'll make sure they don't make noise, for you. It may include a few stops from 100-120 to near stopped, but we will get it taken care of.

On a side note, if you have a pressure washer, give the rotors a good spray down, to get any loose contaminants out of the holes of the rotors. That noise you're hearing is fine glazing that you're getting between the rotors and the pads. You're getting that perfect resonance, like you would get if you were sliding a piece of furniture across a wooden floor, or pulling a chair out, to sit on. Same Noise.

You need to take them out, and knock the stank off of them, a little. If they ever start making this noise, steel or CCBs, you're not hard enough on the brakes. You gotta get out of Miss Daisy mode, and get on them, a little.

😂 OK, ok. I gotta change my M2 button to be less Miss Daisy.

But good info. I'm taking a drive up PCH today with the wife and I'll be sure to exercise the brakes. Might go try the pressure washer approach now as well. Definitely happy to know this isn't a defect in these {expensive!} rotors.

[Limegrntaln]

Originally Posted by m.dreamin

😂 OK, ok. I gotta change my M2 button to be less Miss Daisy.

But good info. I'm taking a drive up PCH today with the wife and I'll be sure to exercise the brakes. Might go try the pressure washer approach now as well. Definitely happy to know this isn't a defect in these {expensive!} rotors.

BMW dealt with a lawsuit a few years ago, and had even taken the brakes off of the ordering sheet, while the lawsuit was going on.

BMW can't exactly tell their customers to go out and drive the car harder, but that's what's been my practice, with the last 5/6 sets of Brembos I've had on cars. My C7 and my Type R brakes, which are pretty much the same rotor and pad compound as the steel BMW brakes, definitely got exercised.

All I can see, in my head, when I hear about about people filing a lawsuit over how loud the CCBs are, is the BMW guy, from Hot Tub Time Machine.

[Likeanowl]

Originally Posted by m.dreamin

Good to know. Also surprising that they'd make noises in the summer. I took delivery in August and never heard this hum sound, but I suppose it takes time for the pads and rotors to settle in together, which I'm guessing is what happened to mine.

It's definitely not ideal and sometimes is a jarring sound, but for now I'm not having to deal with the massive brake dust issues I had with my F82. I can't stand dirty wheels, and yet I couldn't keep up with the dust from the M compound brakes.

Given these brakes are massively expensive, my fear was that this sound was something ominous.

I do agree, having no brake dust is wonderful. But between the non stop noise and the constant paranoia of something as expensive as those are going wrong, it was just too much stress for me. I will admit though, CCB’s do look 10x better than steels do. Or at least on the F80 they did. The rotors were larger and had that nice ceramic “cracked” look. Not to mention the bright gold calipers.

As some have stated, maybe try bedding them in a bit, when safe of course. I had no luck when I tried. Always within a day or two the ridiculous loud squeal would return. Good luck my friend! Let us know what ends up working.

[m.dreamin]

Originally Posted by Limegrntaln

BMW dealt with a lawsuit a few years ago, and had even taken the brakes off of the ordering sheet, while the lawsuit was going on.

BMW can't exactly tell their customers to go out and drive the car harder, but that's what's been my practice, with the last 5/6 sets of Brembos I've had on cars. My C7 and my Type R brakes, which are pretty much the same rotor and pad compound as the steel BMW brakes, definitely got exercised.

All I can see, in my head, when I hear about about people filing a lawsuit over how loud the CCBs are, is the BMW guy, from Hot Tub Time Machine.

Well, you nailed it with your advice. I didn't use my pressure washer but instead just used a high pressure hose with the direct stream. Sprayed the rotors and tried to get the stream in the tiny gap between pad and rotor. Even with just that spray the brakes never hummed the entire day. We did a small road trip up PCH to Gualala with our neighbors and their kiddos, so we were low speed the whole way while we caravan'd. Even without a heavy braking exercise they were silent.

I'll still get it out for some hard braking but for now I really appreciate the advice about pressure washing. What a game changer yesterday! 🙌

[m.dreamin]

Originally Posted by Likeanowl

I do agree, having no brake dust is wonderful. But between the non stop noise and the constant paranoia of something as expensive as those are going wrong, it was just too much stress for me. I will admit though, CCB’s do look 10x better than steels do. Or at least on the F80 they did. The rotors were larger and had that nice ceramic “cracked” look. Not to mention the bright gold calipers.

As some have stated, maybe try bedding them in a bit, when safe of course. I had no luck when I tried. Always within a day or two the ridiculous loud squeal would return. Good luck my friend! Let us know what ends up working.

Yes, admittedly there is a constant level of stress that comes with these brakes. When I installed my front/rear spacers, taking the tire off was a meticulous exercise in *slow* movements.

But thankfully I took Gregg's advice above and sprayed them with high pressure water, and that did the trick at least for the short term. If I have to do that every now and then, that's fine by me. I do love the low/no brake dust and they do indeed look fantastic. Here's a sunset shot of these beauties.

[Limegrntaln]

Originally Posted by m.dreamin

Yes, admittedly there is a constant level of stress that comes with these brakes. When I installed my front/rear spacers, taking the tire off was a meticulous exercise in *slow* movements.

But thankfully I took Gregg's advice above and sprayed them with high pressure water, and that did the trick at least for the short term. If I have to do that every now and then, that's fine by me. I do love the low/no brake dust and they do indeed look fantastic. Here's a sunset shot of these beauties.

Glad it helped, Mike. I gave you both solutions, just to make sure the noise would be gone. If just spraying them off, helps, you should be good for now. There is likely still a glazing on the rotors that need to be cleared off. You'll just take care of that when you can drive it a little more aggressively.