I have about 1200 miles on my car. I've noticed recently (although it may have been present when I first got the car) that it feels like the brakes rub against the rotors at low speed, either (1) when I'm backing up after starting the car or (2) in stop & go traffic when I apply the gas after a brief stop. I've spoken to my MB service rep and he claims that this is normal, a function of the electronic brake application (i.e., the car senses when your foot is off the accelerator and moves the brake pad closer to the rotor). Has anyone noticed this on their car (is this normal)? If so, have you done anything about it?

 

Is it a "feel" or a "sound"? What you are describing is not normal nor is the salesperson accurately describing what MB claims SBC does. It is supposed to "wipe" the rotor when raining and this should be impossible for you to detect and even if they do "move closer” that doesn't mean, "erroneously applied" as you infer.

Good luck with the issue!

 

It is actually normal. At low speed when you sometimes gently hit the brakes there is a 'vibration' feel coming from the brake pad and when i mentioned it to the service advisor he claimed that it is the sensors and is totally normal.

 

My car does the same.Normal procedures.

 

From these observations, I say normal as well.

 

I don't believe US-SBC cars have the predictive braking feature. I think what you are feeling is the SBC pump working.

You might have a loose caliper spring...My SL had that problem causing very noisy brakes at low speeds. I'm not sure if the 8pot calipers suffer from that problem.

 

Hi guys, sorry to revive an old thread but I just got my '04 E55 a few days ago and I'm having that vibration at low speeds also. It is only occasionally - I haven't been able to pinpoint when it does it.

If this is a normal thing, what is the purpose of it?

 

I think I know what you're talking about. I'm sure you are not referring to the infamous SBC groan+vibration cause I believe every E55 owners would notice it right away from day one! The noise that you were describing... is it something like a "sanding" sound that you hear at low speed only when the windows are roll down?? It also makes me wonder if its coming from the brakes. I don't know if this is normal... Anyone?

 

After six months and 6000 miles, I have to say that this has become a non-issue for me. I don't know if the car has adjusted during the break in period or if I've just grown accustomed to the issue, but I do not notice this where once it drove me crazy. After evaluating my car's performance, here's my hypothesis on what previously caused the vibration/rubbing:

1) Our cars do have the adaptive braking feature, i.e., the brake pads/assemblies automatically move closer to the rotors when you take your foot off the accelerator. The initial calibration may not make allowances for the new brake pads and thus causes some rubbing until the brake pads wear to within the normal tolerances;

2) In driving my previous car, I was more of a "straight from gas to brake" driver. I would calculate how much direct force/pressure was necessary to bring the car to a stop, understanding that there was direct feedback from the brakes. In my E55 (and I guess, in all Mercedes with these adaptive brakes), there's no direct linear correlation between pressure applied and braking force. Rather, it seems that the first light pressure applied causes much of the braking force to be applied, until the car is stopped. As such, with a different braking system, it takes some time getting used to it -- an exercise in understanding what force you apply to the brake pedal and how it translates into stopping the car.

3) That said, I do notice that the brakes are more sensitive when a) I first start the car or b) during sharp turning while the car is still cool. I also notice that the brakes feel differently when I'm driving down the highway and come across a patch of stop-and-go traffic. It seems that the car wants to apply the brakes quicker when I just want to coast, creating the slight rubbing/vibration sensation.

Hope that helps.