Bedding is only to bring the best brake performane from the brakes. It does nothing to prevent rotor warping, which has been the topic from the start of this thread I understand.

If you get deposit of the pad material on the rotors yes you can clean it off by bedding/dragging the brakes. This is totally different issue though.

Warped rotor is a defective brake rotor issue where the rotor cannot handle the heat load during braking. Yes, the extreme driving would require better rotors agains this but these cars are basically family sedans engineered and made to operate very hig speeds, which still is not extreme driving. The brakes in these cars should easily handle any driving conditions here in U.S. Brake rotors warping just simply says the rotors are bad.

 

I bought the car in Arlington, VA, i.e. Washington, DC Area with just short of 15 000 miles on it. Brake pads in front were at little less than half. The CPO check should have changed them but amazingly (yeah right) it did not. I replaced the pads around 30 000 miles. Don't remember exactly.

I took the car down south where the climate in general is quite hot at summer times. My driving is 85-90% highway but the previous owner in DC area probably had more city driving. It had to be as the brake pads were so worn.

I think my car's rotors got the normal treatment before I got it. Under my ownership probably little more gentle as I drive so much on highways. But, as others have lost them rotors early mine should have had problems too but they are as smooth as the brakes han be.

Perhaps this has something to do with the build date of the car. Mine was built in June 2009. Maybe MB used an older and better brake rotor maker then?

 

No, read post #172. You want deposits but not concentrated in spots. Bedding transfers an even distribution of the pad material to the rotor and must be done immediately after installation.

 

You go ahead and bed your brakes. I am not going to do it ever other that if I replace pads only. I don't think 99.99% of all car owners in the whole world are going to bed their brakes either.

 

OK, your call obviously. But don't say it doesn't work. Here's a short technical paper from Bosch that mentions judder and how it's caused by uneven material transfer. http://sem-proceedings.com/19i/sem.o...n-Problems.pdf SAE paper. 2000-01-2774

 

Please folks, go to the StopTech site and read their technical papers on brakes, including the myth of "warped rotors". These papers and numerous others, document years of research and development in brakes--millions and millions of dollars in research and they all say one thing--BRAKE ROTORS DO NOT WARP, they have never seen a warped rotor. People use that term incorrectly, including most professional mechanics. ROTORS GET UNEVEN DEPOSITS THAT CAUSE JUDDER. These deposits are then measured as high and low spots/ different thicknesses, and folks incorrectly call it--warped rotor when it is not. Brake bedding's main purpose is to eliminate uneven deposits that cause judder.
From one of their experts:

The "Warped" Brake Disc and Other Myths of the Braking System
by Carroll Smith

Myth # 1 – BRAKE JUDDER AND VIBRATION IS CAUSED BY DISCS THAT HAVE BEEN WARPED FROM EXESSIVE HEAT.

The term "warped brake disc" has been in common use for decades. When a driver reports a vibration, it is attributed to "warped discs". They then measure the disc thickness in various places, find significant variation and the incorrect diagnosis is cast in stone.

In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV)
........................................
--- In his 40 years of experience as a brake expert, he's never seen a warped rotor. It is always thickness variation (TV) which brake bedding helps prevent. Brake bedding lays down an even thin layer of brake pad material as a base.
Without brake bedding, you get uneven deposits, tiny thickness variations at first. Then, like driving down a gravel road with slight ripples- the ripples get deeper. On your rotors, the hills and valleys get deeper---then judder. To make matters worse, when the peaks
are really built up, just a tiny portion of the rotor contacts the pad (all the peaks). They get a terrible heat build up, so hot that the rotor metallurgy changes to cementite, an extremely hard variation. Yes, the cementite can be "turned down" if the rotor is turned but there is bad news. The cementite change has gone below the peaks, into the rotors. The turned rotors start out smooth BUT the non-cementite areas wear faster than the cementite areas and you are soon back to peaks and valleys and judder.

-Brake rotors don't warp
-They get thickness variation (TV) from uneven pad deposits
-Brake bedding lays down an even base of pad deposits
-A rotor with even pad deposits is a happy rotor
- 2010/2011 E 550 rotors are very susceptible to uneven deposits/thus judder.
- Brake bedding is scientifically based.
- You may be smart to get aftermarket rotors/pads like one guy here did from StopTech, great choice!!
- StopTech clearly and explicitly says---BED YOUR NEW ROTORS/PADS TO AVOID JUTTER .

 

As you can read Mleskovar and MinnBobber are quick to cite over and over other sources as bedding testimony. They drive E350s. The vast majority (Mleskoar, do you really want me to post the %, you know I like stats) on this thread drive E550.

Who drives a E550, bed their brakes, has over 18,000 miles with original equipment and support these two in their statements?

Anybody? Anybody?
Bueller?....Bueller?..... (from Ferris Bueller movie).
ha ha!

 

Yes, I agree 100%

 

But you do bed them, you just do it over time and not right away. It's the reason they have a "break in" period specified in the owner's manual, where they are not fully effective after so many miles. In that time, you are "supposedly" depositing an even layer of the pad material across the new rotors. Some of us just do it right away. In the end, both methods should result in the same, effective breaking ability.

 

Ok since we've all been discussing bedding and whatnot, I decided to pay slightly closer attention to the brakes of the vehicles I've been working on and what their rotors look like and the variations between pad material and so on.

Here's what I've come up with: It seems as though this bedding process only applies to NAO (Non- Asbestos Organic) pads. The stock Infiniti pad is one of these pads. And these do, in fact, leave a residue on the surface of the rotor. On several cars over the last few days, I've scraped off this layer with my little screw driver.
It seems to me, that this does not apply to semi metallic pads which do scrape away any sort of residue on the rotor surface. I recently replaced the front brakes on my E55 and used semi metallic pads. I did this for a few reasons. First and foremost was the dusting. I hated driving my car for 200 miles only realize that my front wheel were black. Secondly, cost.
So far I've put approximately 700 miles on these brakes and there is no transference of pad material to the rotor surface. There's nothing that can be scraped away. It's just metal. And best of all, my wheels are their normal color.

From what I've noticed though, the Semi Metallic pads are louder under normal braking conditions, however, I feel as though they stop better as well.

If you all want I can take pictures to show you.

 

About the brake pad material, I don't think it has been legal to use asbestos containing brake components in the U.S. for the past 20 years or so. Everything for sure now is non-asbestos.

The layer on the rotor. Are you sure you are not scraping a thick dust layer on the rotors with your screw driver? This would be the same dust that covers the rims and makes everything on the front wheels look so dirty.

If it is the dust it has nothing to do with bedding that has been discussed. If this layer would be strong enough for the pad to ride on it then the rotor surface under this scraped pad material would be as new. Was it? I seriously doubt it was. But if it was then Infiniti has invented a brake system that wears only pads while rotors last forever.

I think you can find the same layer of dust on the MB rotors, the very same dust layer that dirties the wheels so bad you yourself decided to replace the pads with better material just like I did. And it seems all the customers here with the warped rotor problems run with the original components, i.e. With the dust layer on rotors and they still warp.

 

The reason we can/do cite "other sources" is that it's a generic problem that others have spent the time and money to understand, solve, and share. Judder is well known, documented, been around since disk brakes were invented, and you don't need to have an E550 to experience it. I'm perplexed as why you would think brake judder is indigenous to E550s? Do you think God picked that model to suffer for the sins of brake judder? As far as anyone doing it and then going problem free just look to all the people that haven't had problems because all pads go through material transfer/bedding. Some are not successful. Forced bedding takes the guess work out of it and precludes you from doing the transfer under adverse conditions where you have no control. Since bedding is free with no skin off of anyone's butt what's your problem with it? And I agree that in a perfect world you wouldn't/shouldn't have to do it and that it may not help some. Changing up to more aggressive pads might help as well but that has it's own drawbacks.

 

They all do it to some extent but I'm surprised you can scrape any pad material off at all. It's an extremely thin layer of material mixed in with the rotor surface. I would think that if it were thick enough to scrape off then something is wrong.

I found that the higher performance pads that dust less also fade less but take more pedal pressure and don't "bite" as well. They also require warm up and I agree a bit noisier. My last Benz dusted so bad it was worth the trade off. This one doesn't but I also drive less and almost never in rush hour freeway traffic that really abuses brakes. The really positive side to more aggressive pads is they're usually rotor friendly and seem to last forever going 4 -5 times more distance than the OEM pads.

 

mleskovar,

Do a favor for everybody reading this thread.

Start another new thread explaining about the benefits of the brake bedding for people who have an issue that can be solved doing the bedding procedure.

I have learned in this thread that bedding does not fix issue that some of the posters here have, posters that started this thread. they have the issue of very badly performing brakes with very "vibrating" responce from the brakes that has absolutely nothing to do with some "imagenary" layer of brake pad dust on the rotors. It has everything to do with mechanical issues, like the brake rotors getting warped, which a very reliable source has told he has witnessed too.

Then see how many discussion partners you have...

Personally I think you do not know much about the brakes. The world is full of cars with disk brakes and in general they do not have issues like the E550 and perhaps some E350 MB models have. If the bedding was the needed practice to prevent the judder or other kind of vibrations this issue would be in the national news in TV. But this is not an issue in the cars in the world, just an issue in the cars with bad brake rotors.

The manual for the car may give instructions / warnig about the brake performance not being at it's best before some mileage is driven but it does not say one word about the brake rotors possibly getting warped resulting in "judder" behavior if "bedding" is not performed correctly. Well, if they really would require it they would not sell many cars...

 

I'll stop responding when people stop making incorrect statements about the bedding procedure or asking questions about it. For all the information available about the subject the level of understanding is low....to none. Simple, don't tweak me and I'll stay away. I'm not trying to p*ss anyone off just trying to educate. OK? Arrie, there's no 'imaginary' layer of pad dust. It's actual material imbedding itself in the rotor. I can see you and others either don't accept this or understand it and that's why very early in this thread I said I was beating a dead horse. I keep responding because you and others do. This is a forum and more people than you are reading it. Some understand the technical papers and are getting benefit from them. Ignore me please. OK?

This isn't information that I've made up on my own. Read it, and there's much more out there that hasn't been referenced in this post. I've been repairing brakes for 52 years with no problems. Before disk brakes were common. And it is a very large problem for the manufacturers of cars and parts and they wouldn't have spent the time and money to find the major root cause if it wasn't. Just because "this has never happened to me before" doesn't mean it's not a big problem. If you really believe all these papers were written to just cover the butts of the people making these parts you're mistaken. This is a huge problem in the automotive industry. Open your mind. And I admit that there could very well be a design or parts problem but I don't believe the simplest thing has been addressed yet. Even if bedding cuts down the incidents marginally it's worth it. Peace.

 

It's too bad the original post had "warped rotors" in the title since that got the post started in the wrong direction.

On modern rotors, there clearly/ absolutely/ positively is no such thing as a warped rotor. All rotors are susceptible to TV (thickness variation). Like mleskovar said, this is not unique to MB. Anyone that says they have a warped rotor should call Guiness Book of Records
The rotor measures out at different thickness BUT not because it is warped.
It is pad transfer at different thickness.

And how do you prevent TV? You properly bed your brakes. That's why all the aftermarket rotor/pad companies direct you do so, with your new pads and rotors for all makes/models of vehicles. They are telling you to do this to avoid judder. Besides that benefit, there are many more like pads and rotors lasting longer, reducing brake dust, etc.

If you opt to ignore their instructions (based on decades of research) then be prepared to suffer the consequences--brake judder.

It's that simple. It would be especially important on an 2010/2011 E550 which all agree are pre-disposed to brake judder problems.

Brake/pad manufacturers and others have spent decades and hundreds of millions of dollars dealing with this topic and they all agree on brake bedding.
You can listen to them or your local mechanic's theory--who still calls it a warped rotor......

-Identify the problem
-Find out how to solve it
-Preventative medicine is better than dealing with it later

 

There is nothing imaginary about cementite, it's very common. For these brakes, the rotors do seem crappy, it's just hard to believe that the heat that would be required to bend or otherwise twist/squish these rotors doesn't leave cementite on the rotors as well. This isn't brake dust causing the judder, it's bonded material not visible to the human eye; it's bonded from excess heat.

 

You know what, using statements like absolutely positively no such thing or imaginary deposits are just feeding the fire here. It is not productive.

Rotor runout or thickness variation is common language. ALL brake part suppliers talk about it. Adhesion, brake pad deposits etc, all of them are commonly described all over the place. If you don't want to hear it, fine, do what you want, but they are discussed for a reason. A common source of brake pulsation is uneven distribution of pad material on the rotors, and bedding is supposed to help with this. Why is is so hard to admit this?

HOWEVER!!!!

The documentation states things like very uncommon and myth when referring to warped rotors. This assuredly does not mean absolutely positively. Over the past however many years there has been a lot of research done and manufacturers have figured out how to make rotors that don't warp or bend or deform or whatever you want to call it. From this, non-true rotors just don't happen much anymore. The "myth" and "very uncommon" claims simply assume that manufacturers of brake components aren't lacking in mental capacity enough to ignore or forget this research. Based on what I have read here, I am not sure that this was a safe assumption.

Isn't it possible that both of the hot points of this discussion are true?
Runout exists, and bedding helps prevent this (not 100% effective) AND runout is not the cause of the issue on the E550.

Is it possible that someone that doesn't deserve to be an engineer for a automotive parts manufacturer designed and built a totally crappy rotor and another unnamed bean counter ultimately selected this rotor and had them installed on a bunch of $70,000 E550s?

 

Ok,

you mention cementite. Do you know perlite, austenite, martencite? During my years in school and after school I learned that all these components, including the cementite, are actually different structures steel material takes depending on the incredients it is made of and the heat treatment it receives during and after it is made.

The whole thread here was started with warped rotors. Then brake bedding becomes the issue most talk revolves around.

I can tell you a fact that if the issue with pulsating, vibrating or what ever pad brake behavior the drivers have could be fixed by cleaning the brake rotors MB would exactly do this instead of replacing them. It would be madness by their part to replace rotors that could be easily cleaned and brought to good performance. They would clean them and then instruct the driver to bed the brakes.

But they are not doing this. They replace the brakes because THEY KNOW it is the only way to fix the situation for the moment and pray the new rotors are of the good batch and do not warp or wear unevenly around the rotor.

What the brake bedding talks about has nothing to do with this problem and should be discussed under a different thread.

And I still have not owned a car where the brake rotor had a layer of pad material on it other than the two MBs I had with the OEM pads that made everything covered with dust (loose dust on the rotors) and the Audi Q7 that had the exact same problem.

 

But I believe it's been said many times there may be a parts issue anyway. With only anecdotal evidence/data and both pads and rotors being replaced at the same time you'll never know. I made my own decision after measuring a supposedly "warped rotor"...first with a dial gauge while mounted and then with a micrometer when removed...that the dealer said "your rush hour freeway commute" caused and found them not warped.

 

Are you still sticking with 0.5% of 2010/2011 E550 owners have pulsating/judder/whatever your call it problem?

By the way, I found another poster (tg4e) that just replaced the brakes because of "pulsations" on a 2011 E550.

Anecdotal - definition..(adjective.),.unreliable, untrustworthy, based on rumour.

What are you saying about the 30+ posters that have complained????
These complaints aren't second hand. Some are truly upset. The evidence/data is their testimony. You don't believe them? Why? You think they are liars?

 

Yes, what he's saying is those areas of the rotors that have excess material transfer turn into cementite. Not good

First read post #59 in this thread. Don't confuse MB dealer with MB. The dealer only gets reimbursement for warranty work when MB approves it and the rate they get isn't always what they can make doing the same job on a time and materials basis. If they can tell/convince you the failure is not covered by warranty and make more money but get the same repair results then guess what happens. Unless they did the bedding for you they couldn't verify it was done correctly and the time (for them) doing it wouldn't be cost effective unless they charged you minimum hour. They make more money from set jobs than minimum hourly. I know, there is no Santa Claus

 

Actually I believe that is what MB is sticking with and they have the data.....don't they? If you believe you are going to trump MB's data you're mistaken. For a tech to spit out those stats you know he was quoting corporate. It rolled off his tongue too quickly.

What a coincidence, so did I!!!! He's on the "other" forum who started a thread "warped disk brakes". You could add him. Interesting statement in his thread starter...." I've always had this problem with all my cars. I know I stop hard and fast, so I've just grown accustomed to having to replace my rotors more frequently. However, it seems worse in the CPO 2010 E550 I purchased in December." Sounds like we can both cite him He even thanked me for my suggestion to bed his brakes. Go figure.

I'm not saying these people are making up stories about failures, I'm sure they have better things to do and I've also been in their shoes with dealers. You have pads and rotors being replaced and documented so that's hard evidence of failure. I guarantee you "warped rotors" is classified by MB as customer caused. Doubt it? Which part is the culprit, if not both, is irrelevant to the fact that there was a failure and both are replaced anyway yet they specify rotors. The anecdotal part you have to overcome is the why. If the customer pays to have it replaced it's because they caused it. If MB replaces it for free/warranty it's because MB is promoting good will. And they have the work order/evidence to prove why. You can't win. You're saying it's because the parts were either defective or designed wrong and MB is saying it's neither, but a customer failure and we're just being nice when we do it gratis. Of course the customer says "I drive normal and under normal conditions". Their why is anecdotal but MB can show evidence that 99.5% success rate with the part is sufficient to say .5% of the failure is the user's fault by....take your pick...A riding the brakes B late braking C adverse conditions. "It's a common problem in the industry." Your evidence/data is anecdotal and MB's is not. That's what I'm saying. Wrong?

 

If all 30 of the owners that have reported rotor issues with the E550 were lumped in with the 10's of thousands of E550 owners that do not have any issues, I would think the percentage of actual problems would be very very small.

 

1. I assume that the bedding process described below can do no harm.

2. Since it's difficult to determine as a reader of this thread whether bedding has any relationship to improving brake/rotor/pad life, then bedding would seem a reasonable preventative thing to do, whether it works or not........

I'll also check with the service manager to get his opinion when I order the car.

So, when I receive the car in September, on my drive back from Minneapolis to Maine, I expect I'll do the following bedding procedure, "Just in case".

HBH

From 60mph, gently apply the brakes a couple of times to bring them up to operating temperature. This prevents you from thermally shocking the rotors and pads in the next steps.

Make eight to ten near-stops from 60mph to about 10-15 mph. Do it HARD by pressing the brakes firmly, but do not lock the wheels or engage ABS. At the end of each slowdown, immediately accelerate back to 60mph and then apply the brakes again. DO NOT COME TO A COMPLETE STOP! If you stop completely and sit with your foot on the brake pedal, you will imprint pad material onto the hot rotors, which could lead to vibration and uneven braking.

The brakes may begin to fade after the 7th or 8th near-stop. This fade will stabilize, but not completely go away until the brakes have fully cooled. A strong smell from the brakes, and even some smoke, is normal.

After the last near-stop, accelerate back up to speed and cruise for a while, using the brakes as little as possible. The brakes need only a few minutes to cool down. Try not to become trapped in traffic or come to a complete stop while the brakes are still very hot.