SteveVukelich

My 2014 S550 has 1800 miles, and when I back up and lightly touch the brakes to control speed they screech loudly. It is so loud that people a block away can hear it. I can't determine which wheel (seems like all four). The dealer disassembled the brakes on all wheels, found no problems, and them reassembled them. Any ideas what is going on? It sounds like metal-on-metal, and I am taking it back again. Do I have them replace all of the brakes, or look somewhere else for the problem?

DaveVY

I don't see anything about this in the manual but on a prior sports car we had it was important to "bed-in" the brake pads and rotors to have consistent performance without brake noise. Although the S isn't a sports car I believe the physics and concept still fit for this sedan.

Do a search for brake pad bed in process. Various brake pad manufacturers have slight variations on the process but I have found that this basic process does provide both quieter brakes in addition to consistent performance. This process has you drive the car up to 35 mph and then quickly slow to 10, then accelerate back to 35 and quickly slow to 10 again. Repeat this slowing process 10 times and then repeat again but going from 45 down to 10 mph. Repeat this process 10 times. It is IMPORTANT to NOT come to a complete stop during this process -- you don't want the hot brake pad sitting on one particular spot on the rotors.

After completing the 10 slow downs from 35 mph and the next 10 slow downs from 45 mph continue driving for another 20 minutes to allow the brake pads and rotors to cool.

This process heats the brakes up and allows the pads and rotors to properly set or bed in transferring braking material uniformly to the rotors. Once done with the 20 minute cool down then park the car and allow to cool - do NOT use the parking brake at this time.

This process has helped us - do your own research and determine if you want to try this.

SteveVukelich

Thanks for the bed-in process. Unfortunately we just had 6 inches of snow and I will have to wait until things get cleared.

EMPIRE2007

Mine did the same. I had 1500 miles on it. Extremely loud noise when slow breaking or reverse. Dealer replace both front break pads, it seems makes no noise now, but still needs to check after another thousand miles. And also waiting on windshield washer reserve tank, it crack and leak. Dealer say maybe it freezes during the shipping... And anyone out there the drive seat side
heater seat does not work sometime? It goes off after 2 seconds, dealer still can't locate the problem.

Chucky300

I hear screeching too - also at around 1800 miles now.

The center arm compartment also has a little creak noise to it as well.

So does the driver seat when you make turns.

Quadcammer

Try to bed them again guys.

http://www.stoptech.com/technical-su...-system-bed-in

SteveVukelich

Thanks Quadcammer.

torontowino

Unfortunate to hear. My conclusion is that it is a combination of the oem pads and brake dust. I believe if you switch to ceramic pads you will not hear the squeal . You will not hear the squeal if when coming to a full stop you brake hard. I agree bedding the brakes will help, but I doubt it is a permanent fix. Keep the wheels free of brake dust as best you can and brake hard as opposed to riding the brakes.

SteveVukelich

My salesman just informed me that MB is aware of the issue. Their sales manager's car had exactly the same problem and MB decided that the correct fix is replacement of all 4 brake rotors and pads. They are coming from Germany, so it will take a week or so to get here. I asked about ceramic pads, and they want to do the recommended fix first.

Kratos-TM

This is good to hear. It seems it's a common problem, and since my car is not yet built, I'll most likely get the updated breaks.

torontowino

Respectfully been there done that on two CLS 550's . MB will do the pad and rotor thing for you, but at the end of the day unless they switch to a different pad the noise will come back. It has been a common problem and they refuse to do any thing except the pad and rotor swap .Maybe they are listening but I doubt it.

torontowino

they are only swapping the pads and rotors which are likely not in stock and are coming from Germany . I doubt MB is doing anything more. Please don't hold your breath and think they are altering production . Don't get me wrong I do hope they get rid of this issue .

Kratos-TM

Way to kill my hopes....LOL.

rmorris59

I had similar problem on 2014 S550 at 500 miles. Usually was problem first drive of the day, particularly in reverse, My dealer's maintenance summary said "removed glazed surface with sandpaper, lubed pins and contact areas of brake calipers." So far at 1500 miles noise hasn't returned.

SteveVukelich

Got the car back from the dealer after the parts were received. I tried the bed-in process, it helped some but not completely. I advised them of the ideas proposed here. They said that the brakes, especially the front, were designed for all the new safety systems to be able to stop the car in a panic situation, and that replacing the parts is the only fix they will perform for liability reasons. So far, no screeching.

SteveVukelich

Update: Now at 3,600 miles and still no screeching. The dealer changed the front rotors and pads and that did the trick.

Kratos-TM

Good to know...

hcetzneb

Mb is aware of problem and have released a updated front and rear pad set and
Also there is a special install procedure... Have done 10 or so cars so far and not
One came back with noise... Make sure if the dealer is using updated parts

Chucky300

Had mine replaced. Screech is gone.

For real though - you'd think these kind of issues wouldn't happen.

Diesel Benz

Can you elaborate on that special install procedure? Apply some sort of grease on the pads (rear of course) and the pad guides? I've done it a few times on an old car with old pads and it makes a big difference.

Kratos-TM

My car was finished on January 14th. Do you think I have the updated pads or do I need to make my dealer aware of this and get the update before I take delivery?

hcetzneb

basicaly there are numerous fricton spots on the guides and pin retainer..
on the back of the pad some sort of glue type anti vibration spray should be used.. Its actually better to glue the pad to the piston than to have grease there it will use the caliper piston as a sound deadener... one thing
i do also is chamfer the edges of pad and removed alot of the paint on the edges.. this will roll up over time and cause a screaching noise..

After all this i havent heard any screaching or squealing come back..

oh almost forgot mercedes has 2 types of paste use the gold or bronze
color one its specifically made for noisey brakes part number is
A001 989 87 51

hcetzneb

Not sure the new pads are a diffrent compound and also have a anti noise
shim on the back where as the old part didnt.. you could tell just by looking
at the front pads... i would say you have the old ones as the part number
isnt even listed yet they have to be special ordered case by case for now

Kratos-TM

Ok, well if it squeals, at least I know what to do.

Ormond2004

My brakes squeal loudly when braking in reverse, so I will have to take my car in to get this addressed. I have 2,500 miles.

I am glad that it's not just me. I am grateful for the search feature in the forums.