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Old 08-03-2018, 02:57 PM   #41
rumatt
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Is this a Zim rotor thing?
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Old 08-04-2018, 10:35 PM   #42
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Do the rotors looks like this?
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Old 08-05-2018, 05:25 AM   #43
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I had Zim rotors on the e39 with no issues at all. I’m wondering if there is something wrong with the recent vintage of Zim or textar (or the combination) that is affecting this as we both bought recently and are suffering, even though the cars, e46 and f10 are years and generations apart.
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Old 08-06-2018, 09:37 AM   #44
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Quote:
Originally Posted by equ View Post
How could it be the hub if it mostly goes away with bedding and then comes back with a vengeance?

Honestly, I think I'm suffering from the same. My new Zimm rotors and textar pads on the 535i pulse like crazy. I haven't had the time (and space) to go out and bed them, but in my heart of hearts, I don't think it's going to cure it.
During bedding you're using constant hard pressure on the rotor and generally going in a straight line. Maybe this doesn't allow any hub-related deflection to cause uneven deposits, like it could when you're driving normally and braking gently?

I don't know, I'm grasping at straws here.
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Old 08-13-2018, 01:56 PM   #45
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I'm reading Zimmermann's web site regarding "warped" rotors.

https://www.otto-zimmermann.de/en/se...arpedbrakedisc


1. What they describe sounds like exactly what I have. It gets worse over time, and as the brakes heat up.
2. They say to give up and start over with new rotors

"With an increasing temperature, the cementite will build up and simultaneously penetrate deeper into the brake disc material. [...] This can only be remedied through an exchange of the brake discs and brake pads."

3. It is caused by improper "run in". And their run-in does not involve hard braking

"Violent or shock-braking should be avoided during the first 300 km of travel after the change of the brake discs."

But instead: "30 brake applications from a medium velocity (approx. 100 km/h) with a moderate deceleration"
https://www.otto-zimmermann.de/en/se...ml#runinnotive

Conclusion I think I bed them too hard too soon and they are now fcuked. Not only did I include hard bedding (after gentle bedding to warm them up) but I probably went over 60mph. Which Zeckhausen says explicitly not to do.

Last edited by rumatt; 08-13-2018 at 03:55 PM.
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Old 08-13-2018, 04:21 PM   #46
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On the plus side, a set of four Centric C-Tek rotors (good enough) will cost $100 plus shipping from RockAuto. If you feel absolutely compelled to spend more, it's under $200 for the "high carbon" set.
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Old 08-13-2018, 05:02 PM   #47
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On the plus side, a set of four Centric C-Tek rotors (good enough) will cost $100 plus shipping from RockAuto. If you feel absolutely compelled to spend more, it's under $200 for the "high carbon" set.
Works for me. I'll give the Centric C-Tek rotors a try.

These?
https://www.ecstuning.com/b-centric-...2/125.34168kt/

I just realized, zimmermann are also only $105
https://www.ecstuning.com/b-zimmerma...4116855156kt3/

Last edited by rumatt; 08-13-2018 at 05:17 PM.
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Old 08-13-2018, 05:21 PM   #48
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The C-tek set should be ~$25/corner.
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Old 08-13-2018, 05:45 PM   #49
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Oh! Where the heck do I get that deal?

EDIT: I ordered a new pair of Zimmermann rotors for $105. At this point I just want to know if they work if I bed them according to their directions.

I already have a second pair of brand new Textar pads, so it'll be a total do over, this time with by-the-book bedding.


.

Last edited by rumatt; 08-13-2018 at 10:46 PM.
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Old 08-14-2018, 07:18 AM   #50
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$100 for a set of four? I had no idea they were that inexpensive. I would've expected somewhere closer to $100 per corner.
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