nc211

Thanks guys!

I decided to not go the drilled route for a few reasons this time. On mine, the holes seem to get clogged up with brake dust, and I also think they’re acting like a cheese grader on the pad, but could be wrong on that too. On my other cars, including the heavy 2020 GLS, they’re solid rotors. The VW are solids as well and take a lot more abuse than the 212, and never a problem with noise or stopping power. I suspect the ceramic pad change would eliminate the plugging of the holes, but since I’m going to do both pads and rotors anyway, I just decided to go with the blanks. Appearance wise doesn’t really matter to me, I just was a nice quiet stop, which is the case 80% of the time given.

The droning noise - the indi said two of the rims were ever slightly bent. So that’s where I’m starting as I’ve had that nose before when the rim was really bent. But this time, no dealer repair, but a true wheel shop. Fingers crossed. I do think the brakes are contributing a little as well, but I don’t think is the root cause. I think it’s a combination of the bent rim, the drivers side front brake, and potentially a wheel bearing. Given the many many wheel repairs on this car’s history from me and the previous owner, it wouldn’t surprise me if the bearing is a main contributor. I am also likely to ask the guys to replace the front diff gear grease too if we end up doing the front bearings as a pair. You have to pull the passenger side drive shaft to do it. Figured if we’ve got it that far dismantled for the bearing, might as well get the gear oil too..

I do take some comfort in the fact that 5 mechanics have looked at it. 3 said they could definitely hear it when I told them to drive down the smooth toll road. The other 2 drove it down a concrete road that is not very smooth and could not hear or feel anything (figures). Also figures that when I picked it up this morning, the HVAC was on near high and the radio was playing. You can’t hear yourself think when the HVAC is going strong! Duh.... so whatever it is, apparently is not major enough yet. That’s why I’m thinking It’s something that would make sense, like a wheel bearing or dragging pad or something along those lines. We all know the drill with owning a Benz. First rattle you hear and you panic in thinking it’s your flux capacitor and you’re plum out of 1.21 gigawatts, and $10,000... when it’s probably just what it would be on most other cars too...

Left Coast Geek

way I figure it, the holes reduce the braking surface area. IMHO, their only 'function' on a street car is looking cool.

nc211

That’s kind’ve the way I thought about it too. I also wonder if the holes don’t actually prevent the dust from escaping the area faster and allow more heat to get inside the rotor easier. I’m not an aggressive driver and just didn’t see the need for them in terms of usage. Yeah they look good, but not enough to warrant the draw backs in my opinion. I hate the groaning noise they make. In brakes. .I just want to feel them, not hear them.

LILBENZ230

I like the appearance.. but I'd also be open to going with non-drilled rotors. The drilled rotors looked really cool on my W203 because the brakes were oversized.. It had 1" smaller diameter rims with 1" bigger rotors than my W212.

@nc211 can you post the FCP part number for the rotors?

Gazwould

nc211

sure, happy to!

attached are two screen grabs of what I got for the front now...

nc211

One item the dealership did mention on the review of the car in their attempt to figure out the droning noise - rust on the inside of the front rotors. Said it would only make noise when braking. Well...ummm, if the calipers don’t have spreader springs by design and the rotors have rust all over them on the inside, then I’m thinking I might be getting close...

these rotors are genuine MB from a dealership out of Florida back in 2018. The car is a garage queen, don’t live at the beach, and always clean. So, interesting that the MB OE rotor would start rusting on the inside surface in 3 years and approximately 25,000 miles. The outside hub is rusting up too. I’m likely to paint the hubs of the new rotors with matching silver high temp paint before putting them on this week. I did that with my GTI a couple of years ago with matching high gloss black to match the inside of the factory rim. It’s held up remarkably well, and that car is my Lil Peppy Le Mule of errand running. It’s tuned with APR software to around 320hp. Thing is a riot...

Azhy

I was going to make a post but since it’s somewhat related I figure I ask here first. When I use the brakes around 50mph the car and steering wheel shake pretty badly. When I brake at a stoplight the brakes kind of pulsate when I come to a stop. Does this mean my rotors are warped?

CaliBenzDriver

Yep, you've just nailed the text book definition for warped rotors! 👍

Only thing to do is replace them by pair, especially if the soft rotors got grooved by the hard OEM pads.

Great time for an upgrade to Akebono goodness !!!
✌️

Azhy

looks like I hopped into the right thread. My OEM pads still got good amount meat on the bones. Should I wait before replacing?

Left Coast Geek

IMHO, if you're replacing the rotors, you should use new pads, too. the labor involved exceeds the cost of the parts.

cetialpha5

I have just replaced the rotors and pads with the drilled Zimmerman rotors and Akebono pads from FCPeuro. Not worried about any of those not lasting. Put those in a while ago and braking is fine, no issues. If there are, with the lifetime warranty, I'll just get another set. You guys might not be lubricating the brake parts like the glide pins or cleaning off the rust on the hubs so you might be getting rust or whatever causing your braking issues.

nc211

yep, an improperly grease glide pin or perfectly flat and clean hub will certainly cause an issue for sure! I know on mine this was not the case though. I remember doing exactly that when I changed these rotors and pads 25k miles ago.

I think there are 3 issues with our brakes with MB parts.

First, the design - the pad surface leaves a 1mm lip on the outer edge of the rotor surface. It does not cover all the way to the edge. Over time that will become a rusty edge that basically rides along the top/outer part of the pad, of which does not have spreader springs in the design of the caliper, meaning they just glide over the surface of the rotor all the time. I truly don’t understand this design element at all. Never a problem with any car I’ve ever had that spreader springs to release the pad from the surface.

Second - materials - I think the issue is more aligned to the pad than the rotor. The dust just gets everywhere in there, and with the drilled holes, I think gets inside the rotor itself and starts to cake up the inside. And given the lack of spreader springs, the dust just constantly builds up and is always hot, so it doesn’t take much of a stop to begin baking it onto the surface of the rotor, hence the pulsing effect (which, I now have again, and I I’m thinking is a main contributor to the droning noise). But I also think the MB rotors are not of the best quality material either.

third - more service oriented than MB - properly torque the wheel! I can’t tell you how many times I’ve come home after a service from anywhere to find the lug nuts in all different torque settings onto the hub. Clearly a result of the pneumatic drill instead of a torque wrench. Set them properly and it’ll dispens even pressure across the brake hat. Always seems to matter for my cars...

But at the end of the day, I think it’s their pads more than anything else that causes the issues we have. Just too much dust matched with inability to clear the surface and cool down via lack of spreader spring design, means easy buildup to the rotor surface. I think the answer is the ceramic pads instead. Might squeak every once in a while, but at least it won’t gum up the works. That dust is so bad, it’ll take a professional to clean it off from the inside of my rims some day. It’s penetrated into the surface of the inside rim for those that were on the front for too long...

Max_1

Not to step into rotors/pads discussion...
But you just struck my pet peeve.
I learned my lesson when I had to replace rotors and pads that had only 20K miles on them after lug nuts on that car were over torqued and resulted in rotors warping. Of course I could not prove that because damage surfaced only couple of months after I used that place.
From then on, every single time I go for any work requiring taking wheels off, I always state that I need to make sure that this car needs lug nuts to be at 96 lb-ft according to manual. Couple of places argued that it must be 110 lb-ft until I got manual book that cam with the car and on page#314, surprise surprise it is 96 lb-ft. 14 lb-ft is not a show stopper and if applied evenly probably ok.
What I learned is that if I am not stranding right next to the car and watching them actually do it, it will be over torqued at random values just like you said. So now what I do, as soon as I get home I redo it myself with my own tools as soon as I bring the car home.
In one case I went back next day (this place was next to the store that I needed to go anyways) to let the same front desk guy that "wrote down" my 96 lb-ft requirement know that torque was se to close to 180 lb-ft and most likely was done with impact gun instead of doing with a torque wrench. The answer that I got was I think a king of all BS that I heard: "lug nuts do tighten a bit after you drive a car for a while". I did tell him that was the funniest thing I heard all week as an engineer and that we will not be doing any business ever again.

Max

bmwpowere36m3

I agree in your observations @nc211 ... but they are common among MBs and other euros... the individual traits, i.e. dusty OE pads, lip on worn rotors and lack of spreader springs. However complaints of brake shudder, noise and/or plugged holes seems to be more common with cross-drilled MB rotors.

As far as lubrication, it depends on design and manufacturer. Some strictly state not to lube caliper guides that go into rubber bushings like BMW, whereas others do like Honda. I've done both, as long as you use a rubber-safe lubricant (not petroleum based which can swell the bushings) it works like. Now if the bushing is metal, then it definitely need lubrication.

Another area for lube is pad backs which contract caliper and piston. However some MB pads (others may as well) come with adhesive backs (to prevent noise) which are not to be lubricated. Finally pad ears usually need lubrication when there's metal on metal contact.

For W212s with 2pc floating front calipers, MB pads are unidirectional and have adhesice backs. In addition, MB does not recommend lubrication the pad ears/guides, but does recommend for the caliper guides... YMMV.
I've never had issues using the appropriate lube on all contact/moving surfaces (beside pad face/rotor ).

nc211

Thanks M3!

This is the inside of my front drivers side rotor today, and 99.99% sure the culprit for my droning noise as well. Looks like something has been stuck between the pad and rotor for quite some time now (notice the groove running in the middle of the defective area). You can also see that lip along the outer edge too of the rotor. Same lip on the passenger side to which is operating fine.

I have the shimmy as well again.

Replacing tomorrow with the new Zimmerman blanks and ceramic pads.

what is interesting, the outside of the rotor facing the rim itself appears perfect, no real lip on the outer ring. But on the inside of the rotor, well you can see how much the lip has formed. By touch alone, I’d say the inside of the rotor is about 1mm maybe 1.5mm gone, judging by the lip. I’d say something was wrong with the position on that wheel, but it’s the same on the passenger side too. Face of rotor looks great, hardly a lip. Inside of both rotors, different story... Maybe why so many of us with MB rotors get baffled by how we could have warped rotors already. Looks to me, the inside goes much faster than outside appearances would suggest to the naked eye. I have no real emergency stops either, I drive this car very smoothly and easy going...

im fine if it eats up rotors every 25-3Ok miles. Not terribly expensive to replace them. But judging by what the others are saying, I suspect I won’t have to worry about that anymore with the zimm’s now. Although with ceramics instead of semi-metallic, time will tell.

nc211

New rotor and pads are on. I put this adjustment of non-OE in the same category as the iPhone - why did I wait so long to do this! Brakes are utterly silent now. So nice!

no more groaning noise when braking, and a completely smooth stop. I am definitely in the camp with you guys on ditching the MB rotors and pads for the Zimmerman’s and Akebono pads (however you spell it)!

nc211

After an 18 hour drive from DC to FL on Saturday, the new Zimm blank rotors and ceramic pads on the front are the perfect match in my opinion, and no noticeable downgrade in braking performance. But the interesting thing - the rear wheels had the dust (original MB setup) and the front wheels were still very clean. Looked funny to see. Back dirty, front clean, when it’s usually the other way around. I foresee the backs being replaced with the exact same setup in the near future.

bp95gsx

Has anyone swapped OEM Mercedes Carbon Ceramics from another car on a W212 E550? Do they bolt up? I know i will need new wheels. I know brakes are expensive. But they last much longer than steel as long as you are not on track. The reason i want carbon ceramics is because i have a carbon ceramic brake fetish. Haha. Many of my other cars carbon brakes too. I also want the rotational weight out of the car for performance. I am going to research lightweight 19 inch wheels too for E class. It is heavy so i will need a reliable load rating on the wheels. I was able to remove 70 pounds of rotational weight on my C6 Z06 Carbon Edition when i went from stock wheels/tires to Litespeed wheels/Cup 2 tires. Made an already great car, drive unbelievable in my opinion. My custom ordered E550 is sentimental to me and i will keep it forever. So anyone else psycho enough to put CCB on a E550?

LILBENZ230

The E63 had CCBs as an option. Absurdly expensive and completely pointless for street use... but people often pay lots of money for fetishes. As long as you've got the money, this will be possible. I'm not sure you'll save any significant weight and the cost/benefit analysis is poor no matter how long CCBs last.. but it can be done.

Left Coast Geek

I thought carbon/ceramic brakes didn't work well until you get them very hot, so were really only suitable for race track use where you are hard braking into each turn over and over and over. For street use, where you might drive an hour at 70MPH on the freeway without touching your brakes once, then suddenly need to hard brake to avoid an accident, they would be positively dangerous.

LILBENZ230

I think they do work better with heat, but obviously they are fine for street use.. optional on lots of Benz and Porsche cars. I mean, you can get CCBs on a Macan. So while they wouldn't be dangerous, they're just so damned expensive it doesn't make any financial sense.