[BimmerHausPerformance]

Originally Posted by KaiserWil

Hey! I have the very same issue, I had worn out pads so I changed the rotors also. I put on Zimmermann Coat Z rotors and Textar ePad pads. After 20k km, brake pedal started to vibrate while braking. So I took the rotors off and they were visibly damaged - circular dents on the inner side of both rotors. I installed new meyle rotors with TRW pads and it was smooth for maybe 5k km and then it again started. What could it be ? It vibrates only when braking. Did you have any luck finding a solution?

Picture of damaged Zimmermann rotors after only 20k km https://ibb.co/4NyDBrL

Thank you.

Do you realize you quoted something from a DECADE AGO? ROFL

[lucid21]

99%+ of vibration when breaking issues are NOT cause by "warped" rotors. They are caused by uneven brake pad transfer to the rotors. That usually happens when you sit on the brakes for some time (or engage the parking brake which will affect the rears only) when the rotors are really hot. Your pad basically melts onto the hot rotor surface. Just don't do it.

Also, look into the physics of braking. Pad compound is supposed to transfer to your rotors for effective braking. The point is that it should be transferred evenly so that you get consistent friction as the rotor rotates.

Braking hard does not cause warping or some other kind of damage to the rotors (unless you exceed that max operating temps MOT but you won't do that on a street car in the US unless you do 1000s of 0-60 and 60-0s). So anybody telling you that you used your brakes too much or too hard or whatever is full of it. If that was the case, race cars would have toasted brakes after a lap.

One way of fixing a so-called "warped" rotor is to slap on really aggressive pads (I mean aggressive race pads) and then use them to basically machine off the previously deposited brake compound from your rotors and you can start over again. I've done that several times.

Next time someone claims that you have a "warped" rotor, ask them how they know that exactly? What measurements did they take and how are they arriving at the conclusion of "warping"? Ask them to numerically define what warping is means exactly? You'll see that they don't have a clue in general. If they say, I put it on a lathe and turned it and it is fine now so it was warped, that is almost always BS, too. What they did was to simply remove the uneven pad deposits from the surface of the rotor. Not somehow "unwarped" it.

I guess it is *possible* for a rotor to be physically warped but I haven't seen one in 30 years.

[Bmwdoubles_]

My issues with vibration were solved with replacing the upper control arms due to ripped bushing and a flash from the dealer on the electronic steering. I have a very old post somewhere on that service.

The vibration for me has returned but this time it's the lower control arm. Confirmed ripped bushing.

[TEF]

After reading about the use of aggressive pads to machine a problem rotor, isn't that what's done when rotors are turned by a mechanic or dealer. And it seems that after this is done, some still complain of vibrating brake pedals In some cases, even installing new rotors does not help. Perhaps the problem is not the pads or rotors, but rather a worn suspension part.

With my X3 things were not that complicated. I had warped front rotor(s) at 15k miles that were replaced. After 65K miles the problem has yet to return.

[lucid21]

Yes, as I said, really aggressive pads can essentially machine off transferred pad compound so one can start from scratch. The point is the rotors not "warped."

And, yes, there can of course be other reasons for vibrations. What I am saying is that your garden variety warped rotor diagnosis from a dealer is usually BS and the rotors are extremely unlikely to be warped.

[TEF]

Why buy and install aggressive pads, when one can just have rotors turned? Aggressive pads (usually semi-metallic) can sometimes score rotors rather than producing the even, smooth surface of a brake lathe. Moreover, rotors must warp at times, otherwise what's the point of run-out gauges.

[Blue Angel]

lucid21 is correct. Anyone who wants to know more about this should read the white paper from Centric parts, which dispels the warped rotor myth and several others:

https://centricparts.com/getmedia/bd...c-8-2018_1.pdf

[lucid21]

Originally Posted by TEF

Why buy and install aggressive pads, when one can just have rotors turned? Aggressive pads (usually semi-metallic) can sometimes score rotors rather than producing the even, smooth surface of a brake lathe. Moreover, rotors must warp at times, otherwise what's the point of run-out gauges.

Read what I wrote carefully from the beginning. I didn't say rotors can never warp. I said the gross majority of warped rotor claims are off.

High quality aggressive pads do not score rotors. Never had issues with Pagids or the more aggressive compound Wilwoods. Had major issues with Hawks.

Having your rotors turned will cost you dearly unless you have lathe. Swapping pads will cost you 30 mins x 2 if you have the pads. I did that with an e90 m3 that i tracked a lot. Either that was to make the point that if scraping off uneven pad deposits fixes the issue you dont have a warped rotor. Not to say you should go by aggressive pads.

[lucid21]

Originally Posted by Blue Angel

Anyone who wants to know more about this should read the white paper from Centric parts, which dispels the warped rotor myth and several others:

https://centricparts.com/getmedia/bd...c-8-2018_1.pdf

Good read. Matches my observations; the stoptech folks have all the data and do this for a living so I am anactodal compared to them. They do make good products. And appropriately tailor them to each application.

[TEF]

Getting back to "the gross majority of warped rotors" , how does one know which is caused by irregular pad deposits and which is actually warped? What if these aggressive pads do not resolve the problem, does one return the set of used aggressive pads (to Centric) for a refund? This fix may be ideal for DIYers (like yourself) that just happen to own a set of "aggressive race pads", but would be doubly expensive for the majority of owners using dealers and independents for brake work.

Moreover, your estimate of time required for a DIY pad replacement does not apply to all BMW's. Assuming your M3 has Brembo-style fixed calipers (without brake wear sensors) it's possible to change pads in 30 minutes per wheel. However, doing the same on the F10's typically rusty sliding front calipers is rarely that fast and a task that few want to do twice.

Despite my dissent, happy new year.

[BimmerHausPerformance]

Sounds all like semantics to me! At the end of the day if the rotor is the root cause choose your own method to fix it for crying out loud lol.

[lucid21]

I can change pads on an axle in 30 mins with stock brakes. Does require some practice. Turning rotors is way more labor intensive btw. You have to undo large nuts and get the caliper carriers off in addition and then also actually machine them. This all is irrelevant though because, yet again, I offerred the aggressive pad approach as a means for me to verify what I had. Again I am not suggesting that you buy pads or do anything at all yourself. Not sure how many times I need to say that. I am suggesting not to stand on your brakes when they are hot.

Interesting the stoptech whitepaper says the pad approach only works with not too severe cases of uneven deposits. They have more experince so I defer to them.

In terms of proof I refer you to the Stoptech guy who has examined 100s of rotors over 30 years or whatever. Ill sayvthid again: no daily driver is using brakes anywhere close tobtheir mechanical or thermal limits to warp them regrardless of how spirited of a daily driver they may be. I certainly didn't know how until I got specific training on how exactly to do that when I got first got on the track. And that is the first thing I teach beginners on thevtrack. Even if you knew how, you couldnt do it unless you speed and stop like a maniac down the Rockies on public roads or I guess you do multiple emergency stops in Germany from 200+ kph. In general, you may warm up your brakes but you wont get them anywhere their limits with the exception of fluid issues but that is a different topic and not about rotors. I sure dont when I drive around and I am glad I dont.

I have, on at least two occasions, applied the parking brake after rushing to work and stopping at the bottom of a downhill off ramp and thus warming up the brakes right before parking. What do you know, I had vibrations after each occasion. I could even see the pad imprints on the rotors when I looked carefully thevsecond time. Just like the stoptech paper notes...I am extra careful with that now.

What I have also observed a dozen times is beginners standing on their brakes after a track session or when there is trouble on thevtrack and stopping and then reporting vibrations in the next session. I can assure they did not know enough to bring their brakes to any kind of thermal limit.

Happy new year to you as well.

[stefan_bratu@yahoo.com]

Have same problem

Originally Posted by shaunlees

my f10 has now been back to the garage 3 times for new discs (done 22000 miles) as i keep getting vibration through the car under normal braking. When they put new discs on they are fine for a few thousand miles and then the problem returns. You can feel a slight vibration through the car when driving too. Anyone else had anything similar? The car is great but this problem is really getting to me. Ive not had a bmw before, my last 2 cars were lexus and absolutely faultless, bmw is so far proving to be a bad choice.

[coachman]

Hi everyone

[manija]

Originally Posted by stefan_bratu@yahoo.com

Have same problem

as you can see - you are not alone
and there are a lot of cases issued for chassis problems.
so at first try to find good mechanic for inspections, as it can be not brakes problem.

[WTP]

Sorry for jumping on the back of this post, i changed my brakes both front and rear discs and pads however after around a 1000 miles i started to get a shaking steering wheel when braking at speed so i had the front wheels off to check what was going on all seemed well but i noticed on my last mot sheet i had one advisory which was front control arms slight play but should be good for around 7000 miles so i decided to change these for new ones however now having done that i have noticed that with the window open when i brake as i enter my driveway i hear a metal clunk and if i drive say at 5mph and keep hitting the brake pedal it will do it each time any idea what this could be?

[danni400]

Did you found the problem?