Cool, fingers crossed it disappeared forever! Do you have any photos with this set screw visible by any chance?

 

Here you go.

 

I rather thought of the photo with rotor/hub etc. where it will be visible where exactly they are located . Thanks anyway!

 

There’s only one, you won’t miss it.

 

Just noticed noise from driver's side rear brake area this past weekend. Its been cold here in Toronto lately so not sure if temp plays a part. Was at a full stop and let my foot off the brake with no acceleration and heard initially a fairly loud rubbing noise equivalent to a full rotation of the wheel and then nothing. the sound was there after multiple start/stops however less aggressive sound. i have a 2018 coupe with 29k km. Just had a B1 service and brake fluid change about a month ago. Curious if its related to the brake fluid change as I have never noticed this sound previously.
Have not contacted the dealer yet. Hoping this is not a recurring issue as the last thing I want to do is visit the dealership during Covid. I will try and do some hard stops and see if that helps.

 

To the OP and everyone else with brake issues...I bought my 2018 C43 with about 4.5K miles on it. I started to notice the a squealing/squeeking sound pretty much right after I took it home. I took it in to have the brakes looked at about 3 months after I bought it and they recommended new rotors and pads...at 6K miles..

As you can imagine I was pretty pissed that I was being advised to change the rotors and pads on a year old 70K sports luxury sedan. I argued with the service advisor and told them they should warranty it out because there's obviously something wrong. Their excuse for not warrantying the vehicle was that it sat at the dealership (where I bought it) for a long time and was not driven enough. They inspected it and told me that there was a lot of rust in the system. They also told me the rotors and pads still had life and normal wear and that there was nothing wrong with them other than the sound. They applied some grease or something and the sound went away for a couple days. They were going to hit me with a $200 diagnostic fee but they were nice (I guess) and waived it. I drove off and said f it ill put up with the noise instead of replacing the rotors and pads.

I did some research and there was actually very heavy rain and some minor flooding nearby the dealership where I bought the vehicle (Houston Texas) not too long before I purchased it. After I found out about that and talked to the dealer where I bought it I immediately took it back to MBZ and told them to inspect the vehicle which they did for free thankfully. They said there was no damage to anything else but they said it could be why my rotors and brake system/calipers were rusty. They told me to drive the car at 25MPH and slam the brakes, and to also do that in reverse. The noise got a little better after doing that a bunch but still was evident at real slow speeds.

Anyways 8 months after that I got the brake pad sensor light and ended up just replacing the pads and rotors. That was at about 9K miles. Noise is completely gone and has been for months.

I think the key takeaway is that these cars need to be driven and that the braking system is very susceptible to the elements. I feel like that is fairly consistent with most performance cars. I am fortunate I guess in that I have a garage for mine.

 

Heard the noise couple times last week when pulling into garage. Not severe enough to give the dealership a ring yet.

 

Yes, currently I hear it only in such circumstances, fortunately not always and not as loud as before.

 

I had rear pads warrantied last year at 10k kms because it was noisy at low speed to stop. Had to make few videos and the dealer ultimately sending to Germany for advice. Dealer said there is different pad for GLC making noise, but sadly nothing for rear for C. They ended up getting 3m tape to put over new pads but didn't get new rotors. So far no noise after 4k kms. But most likely will go with ceramic pads instead of OEM semi metallic.

Don't forget to put your car into service mode to change out the rears. Thanks!