2012 E550 - Warped rotars for the SECOND TIME
My front replacements (at 9,000 miles, under warranty) were 204-421-11-12
(Interesting, that's also the part number for a 2005 Ford Econoline rotor!
)So far, at 32,000 miles, everything OK, with no change in driving environment.
As an aside, I find LI42.10-P-054524 SEPT12 – 212.072/090/272 front brake vibration. Thickness fault on brake disk replace pads and disks very interesting.
Last edited by Live Oak; Apr 20, 2013 at 05:51 PM.



Besides I wasn't doing any analysis...just offering a suggestion. Speaking of method, you do understand that the 2009 W211 is a different chassis don't you? And how's that data collection going? Getting more replies to match your forgone conclusion since the people are replying to a thread about warped rotors? And now that you brought up the point why are you chiming in when you don't have the problem? Isn't that another of your requisites
I haven't seen any relevant facts or statistics come from anyone yet. Including you. Data and evidence coming in? Like what? How about the evidence that Arrie (not picking on you) doesn't have the problem and he's got 47K on the original rotors? Go clean your own house first.
Besides I wasn't doing any analysis...just offering a suggestion. Speaking of method, you do understand that the 2009 W211 is a different chassis don't you? And how's that data collection going? Getting more replies to match your forgone conclusion since the people are replying to a thread about warped rotors? And now that you brought up the point why are you chiming in when you don't have the problem? Isn't that another of your requisites
I haven't seen any relevant facts or statistics come from anyone yet. Including you. Data and evidence coming in? Like what? How about the evidence that Arrie (not picking on you) doesn't have the problem and he's got 47K on the original rotors? Go clean your own house first.My front replacements (at 9,000 miles, under warranty) were 204-421-11-12
(Interesting, that's also the part number for a 2005 Ford Econoline rotor!
)So far, at 32,000 miles, everything OK, with no change in driving environment.
As an aside, I find LI42.10-P-054524 SEPT12 – 212.072/090/272 front brake vibration. Thickness fault on brake disk replace pads and disks very interesting.
"000-421-15-12-07 Brake Disk"
A little googling shows that number to be a genuine mercedes part. Still curious if it's the heavier version. Will continue to google.
Also says, "Performed LI42.10-P-054524 and replace front brake pads and rotors." A quick search (and as stated in Live Oak's post) resulted in post #90 here. Quote: "...Thickness fault on brake disk replace pads and disks..." Perhaps that's another way of saying, "oops, screwed up"; either by design or poor quality.
Last edited by tjkaz; Apr 20, 2013 at 07:19 PM.




Come clean and tell them what pad you are using. Make sure you disclose the rotor (oem right?) and the mileage.
Somebody copy this setup and verify the solution. It's that simple. Arrie may have solution for all 2010 & 2011 550 owners . Isn't that what the goal is? Everything else is noise.
Posted from Mbworld.org App for Android
I don't think I have the solution. I replaced the pads with ceramic just to control the dusting issues. I changed the pads at around 30000 miles (don't remember exactly) . I did not have any kind of braking issues before or after the pad change so I think I'm just one lucky SOB not to have the defective rotors. I'm sure vast majority of the E550 owners don't have problems and most owners don't come to this forum either so there is no way to know.
The pads I bought from AutoZone. Their own name brand and cost something under $100.



Also, apologies for the long thread.
Some brackground on my problem. I purchased my MY11 E550 as a CPO when it was only one year old (purchased Dec '11). During the test drive I noticed very slight judder but attributed it to some new braking response (my bad). But like I said, it was very slight, and I really didn't push the car too hard and was focusing on differences between the 212 versus the 211 which is the car I was coming from.
Over time, I noticed that the judder got worse after the brake rotors warmed up (not hot) from normal freeway driving. In more agressive stop and go traffic, I noticed the jugger got even worse. I was convinced that the rotors were experiencing warping after they got hot and became less warped after they cooled and began to contract back to their normal shape. My sense was that they were experiencing asymmetric thermal expansion. So why would they expand asymmetrically?? My theory follows.
[FONT=Times New Roman][SIZE=3]First, I'd like to thank "no mulligan" for his research, and inparticular, for the weight differences in model year rotors.....
As for why I had the problem in the first place? As I stated in my conclusions - perhaps attributed to issues with the original rotors, the previous owners driving habits or a combination thereof.

I will add you to my list of people with brake pulsations. Can you tell you how many miles were on the vehicle when you first noticed? So far my collected stats say 13,000 average.
Be ready for my *friends* that can't/won't accept your conclusions. They won't even acknowledge the numbers I collected across 300+ posts are worth anything. You are the 20th person who drives a 2011 E550 to report pulsations.



The pads I bought from AutoZone. Their own name brand and cost something under $100.
Thanks for responding. I was hoping for a breakthrough but you are still interesting. I will keep my eyes open.
The Best of Mercedes & AMG
thanks for trying to educate folks on brake bedding. I agree but hesitate to jump in and get jumped on by the nay sayers.
I'll add 1.an analogy and then 2.technical info from brake pad/rotor companies where brakes / brake research is their specialty. I tried to
summarize/ condense/ highlight it down from pages of info/data/ findings.
3. why doesn't MB recommend it? My opinion why.
1. MB E550 brakes may have a predisposition toward brake judder.
The brake experts agree that proper brake bedding helps eliminate judder.
Analogy: if your family has a predisposition toward cancer, wouldn't you
want to focus on diet and exercise to help. It might not ward of cancer but
it surely will help.
Bedding brakes may not ward off all judder but it certainly will help. It will
increase the odds of trouble-free brakes.
2. Bedding allows your brakes to reach their full potential. Until they are bedded, your brakes simply do not work as well as they can. Proper bedding improves pedal feel, reduces or eliminates brake squeal, prevents (and often cures) brake judder, reduces brake dust, and extends the life of your pads and rotors.
After the break-in cycle, there should be a slight blue tint and a light gray film on the rotor face. The blue tint tells you the rotor has reached break-in temperature and the gray film is pad material starting to transfer onto the rotor face. This is what you are looking for. The best braking occurs when there is an even layer of of pad material deposited across the rotors. This minimizes squealing, increases braking torque, and maximizes pad and rotor life.
Bedding changes the brakes from adhesive friction (pad on metal) to adherent friction (pad on transferred pad material).
The adherent mechanism is altogether different. In an adherent system, a thin layer of brake pad material actually transfers and sticks (adheres) on to the rotor face. The layer of pad material, once evenly established on the rotor, is what actually rubs on the brake pad. The bonds that are broken, for the conversion of Kinetic to Thermal energy, are formed instantaneously before being broken again. It is this brake pad-on-transferred brake pad material interaction on a molecular level that yields the conversion process.
The all-important transfer layer
As stated above, the objective of the bed-in process is to deposit an even layer of brake pad material, or transfer layer, on the rubbing surface of the rotor disc. Note the emphasis on the word even, as uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration.
Let's say that again, just so there is no misunderstanding. Uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration.
It only takes a small amount of thickness variation, or TV, in the transfer layer (we're only talking a few ten thousandths of an inch here) to initiate brake vibration. While the impact of an uneven transfer layer is almost imperceptible at first, as the pad starts riding the high and low spots, more and more TV will be naturally generated until the vibration is much more evident. With prolonged exposure, the high spots can become hot spots and can actually change the metallurgy of the rotor in those areas, creating “hard” spots in the rotor face that are virtually impossible to remove.
They also add that it is almost impossible to warp a modern rotor. About the only way is using a street pad on a racetrack in racing conditions. What people call warped rotors are rotors with uneven brake pad deposits-- yielding high and low spots. Proper brake bedding helps eliminate that.
It may not totally eliminate it and you have to do it properly--where you
see a blue tint from the high temp and a light grey transfer film.
3. And why doesn't MB recommend brake bedding in their owners manual?
I believe it's a "lawsuit" issue. There would be that .1% that performs brake bedding on the freeway , in traffic, slowing repeatedly from 60 mph to
15 mph and they get rear-ended. "MB told me to do this" > lawsuit.
Let the flaming begin......

If there was any sort of deposit on a rotor, you could, in fact, scrape it off with some sort of a tool like a pick.
Rotors DO NOT have any bluing to them whatsoever. If they do it's because they got too hot. Not some BS that it's from bedding your pads. Like I said before, I've worked on cars for a long time, and rotors are not, and never have been, blue under normal driving conditions. Only blue rotors I've seen were ones that had gotten REALLY hot. I've even seen purple ones where the friction surface broke away from the hub.
In regards to bedding eliminating squealing, I think that's just a load of BS by brake manufacturers so they don't have to warranty their substandard products.
THE MOST COMMON cause of brake squeal is not from pad to rotor contact. Squeal is most often caused by a lack of proper lubrication between the backing plate of the pad and the caliper. I can make the crappiest pads, with the cheapest rotors silent.
On the other hand, there are certain brands that like to cheap out on friction material. If you look closely at a semi-metallic OE pad, regardless if it's Ford, or Honda, or MB, they typically use higher quality metals such as copper and bronze. Due to the "softness" of the metals they don't squeal. Some aftermarket companies will replace this material with iron and those will cause squeals. Bedding will not relieve this.
I'd like to address terminology just so we're all clear. A shudder or judder is a violent vibration that will literally shake the whole car --violently. Think shaken baby syndrome, but your car. A pulsation is when it's mainly felt in the pedal and very little is transferred to the rest of the vehicle.
As for "hard spots" that are "impossible" to remove
. It makes me wonder if the person that wrote that has ever turned a rotor in their life. You can remove any material from a rotor. Period. I have turned literally THOUSANDS of rotors, and I have never come across one with a "hard spot" you couldn't remove. If that were true, when the lathe would get to that spot, it would stop or break the cutting bits. Has never happened.All of that sounds like utter BS to me. It sounds like a very eloquent excuse.
Last edited by BlackOmega; Apr 21, 2013 at 12:37 AM.
by Matt Weiss and James Walker, Jr. of scR motorsports, exclusively for StopTech
James Walker, Jr. is currently the supervisor of vehicle performance development for brake control systems at Delphi Energy & Chassis. His prior professional experience includes brake control system development, design, release, and application engineering at Kelsey-Hayes, Saturn Corporation, General Motors, Bosch, and the Ford Motor Company. Mr. Walker created scR motorsports consulting in 1997, and subsequently competed in seven years of SCCA Club Racing in the Showroom Stock and Improved Touring categories.
Through scR motorsports, he has been actively serving as an industry advisor to Kettering University in the fields of brake system design and brake control systems. He also serves as a brake control system consultant for StopTech, a manufacturer of high-performance racing brake systems. In addition, Mr. Walker contributes regularly to several automotive publications focusing on brake system analysis, design, and modification for racing and other high-performance applications. He is a recipient of the SAE Forest R. McFarland Award for distinction in professional development/education. Mr. Walker has a B.S. in mechanical engineering from GMI Engineering & Management Institute.
Their info applies to all brake rotors and pads: street , racing, non-MB, MB.
They are NOT making excuses for MB brake judder problems. They state that brake bedding is the single most important procedure to prevent brake
judder, brake squeal, brake dust, etc. They have no "pad to grind"

Their lifetime of work with brake systems (research, development, testing)
has shown the value of bedding.
It amazes me that folks can LOL about bedding. It's brake science--abrasive friction vs adhesive friction.
Do you want to try to prevent the "brake judder cancer" or feebly try to
"cure it" it after it appears. It might not prevent all judder but it's sure worth
trying IMHO.
Flame suit on again




I call that covering your ***.
Is bedding
?
My suspicion is it would probably also require a caliper and carrier change in order to do so.
The added unsprung mass might also dictate a suspension spring rate change.
With that said, I'm contemplating a CPO 2010 E550 and would be a whole lot less concerned about the rotor issue if viable easy fix were available.
It also could be negotiated up front prior to the deal being closed.
Thx.
When I purchased the car, it had ~14k miles and was about one year old. I did notice a subtle judder, but only the original owner would know exactly when it started. However, I would say that it's certainly in the realm of your statistics (one sigma
).




My suspicion is it would probably also require a caliper and carrier change in order to do so.
The added unsprung mass might also dictate a suspension spring rate change.
With that said, I'm contemplating a CPO 2010 E550 and would be a whole lot less concerned about the rotor issue if viable easy fix were available.
It also could be negotiated up front prior to the deal being closed.
no_mulligan posted earlier the history of front brake rotor weights from 2009 to 2010/11 to 2012. 2009 rotor used to be 25.6 lb, 2010/11 18.3 lb and 2012 35.6 lb.
I don't know if the 2009 models had issues but if the added weight is the solution, which it very likely is, you can get heavier rotors from third party.
Just checked AutoZone site. They sell 2010 front rotors ready to bolt on. Their own Duralast brand has weight of 28.7 lb, 2 year warranty for less than $90. Raybestos is 29.0 lb, 1 year warranty just over $100.
I would go with the Duralast as Autozone has been very good with warranty returns if needed. Like my daughter's car wore out brake pads after several years and they gave new set free as they sold them with life time warranty. No questions asked, just presented the receipt.
When it becomes my time to replace the rotors these are the ones I will put on.
Last edited by Arrie; Apr 21, 2013 at 05:02 PM.



Originally Posted by boltonblue
I certainly would be curious to see of the heavier set up from the '12 could be easily (i.e. bolt on)substituted for the '10 brake rotors.
My suspicion is it would probably also require a caliper and carrier change in order to do so.
The added unsprung mass might also dictate a suspension spring rate change.
With that said, I'm contemplating a CPO 2010 E550 and would be a whole lot less concerned about the rotor issue if viable easy fix were available.
It also could be negotiated up front prior to the deal being closed.
no_mulligan postet earlier the history of front brake rotor weights from 2009 to 2010/11 to 2012. 2009 rotor used to be 25.6 lb, 2010/11 18.3 lb and 2012 35.6 lb.
I don't know if the 2009 models had issues but if the added weight is the solution, which it very likely is, you can get heavier rotors from third party.
Just checked AutoZone site. They sell 2010 front rotors ready to bolt on. Their own Duralast brand has weight of 28.7 lb, 2 year warranty for less than $90. Raybestos is 29.0 lb, 1 year warranty just over $100.
I would go with the Duralast as Autozone has been very good with warranty returns if needed. Like my daughter's car wore out brake pads after several years and they gave new set free as they sold them with life time warranty. No questions asked, just presented the receipt.
When it becomes my time to replace the rotors these are the ones I will put on.
I hope someone finds the perfect solution for all. And, I include extreme drivers too although I don't know what that means. *smirk*
Thx Arrie!!
Posted from Mbworld.org App for Android
developing brake judder but it is not a GUARANTEE. And that is addition
to the other documented/tested brake improvements of bedding.
That's just like any preventative measure/procedure, if you can grasp that
concept. Do you want the best odds of no brake judder OR do you want to
just let it ride, with a brake system known to have judder issues ???
And we're not talking some expensive procedure, it's free .
Ask them about it. Good rotors I'm told BTW.
Million? WAY more than that and the real question is how many needed to? Not many. It's obvious the pad/rotor combination on the '10-'11 E5XX isn't up to the task for many owners so why not do everything possible to mitigate the symptom?




Claiming the drivers do extreme driving with these family cars causing warped rotors and that bedding is the solution for it is total BS. Our "expert" mleskovar seems to have softened a bit though. He goes to say " It's obvious the pad/rotor combination on the '10-'11 E5XX isn't up to the task..." when before it was just about the need for bedding the brakes properly.
In my opinion bedding is only needed when new pads are put on used rotors. Used rotors have grooves so the flat new pads need to be "worn in" to the surface to match the grooves. Until this is done the brake performance is not quite at the best level. This has NOTHING to do with rotors getting warped.
In my opinion bedding is only needed when new pads are put on used rotors. Used rotors have grooves so the flat new pads need to be "worn in" to the surface to match the grooves. Until this is done the brake performance is not quite at the best level. This has NOTHING to do with rotors getting warped.
Last edited by thekurgan; Apr 22, 2013 at 12:38 PM. Reason: really bad speller
If this were true it wouldn't still be happening. New part number doesn't necessarily designate redesigned part....but it may, or it could be something as simple as an anti oxidant coating to keep the part pretty until used. My guess is the problem lies in the pads being too 'soft' (another technical term).
Often, a screwed up part is screwed up for only a percentage of the production.
After all, only three of the Boeing 787 batteries burned up in airplanes in flight!! Must not be a problem with the batteries, or the airplane!! Otherwise, all of them would have fallen out of the sky!




