Blue brakes - United Bimmer Community

**Martin Long** · 07-06-2006, 03:37 AM

I recently fitted new Zimmerman rotors and Bendix Ultima pads to my 94 E36 M3, two weeks later I did some track work, actually it was a racing driver training course.
As the day progresed and my speed increased, braking distances got shorter until at the end of a downhill straight (190kmh) into a 90degree right hand bend, I found to my suprise I had very little stopping power and almost ended up into the kitty litter, fighting to stay on the track.
I proceeded to do a cooling off lap and when I returned to the pits all four rotors were blue. I have only driven the car for 1-2 days since and the rotors are still slightly blue. My question is do I need to remove the rotors and skim them, or will they bed in within time and return to the metalic shiny surface?

Storamin · 07-06-2006, 05:40 AM

now that is what the car's are all about! chances are the junk on th rotors will cause you have to have a wheel shimmy during braking, so it's a good idea to have them turned.

have you changed your brake fluid?

**Dudesky** · 07-06-2006, 06:59 AM

Sounds like they weren't bed in properly beforehand, which needs to be a controlled, gradual and consistent procedure. The track session was way too harsh on them

I agree, you may want to have them turned beyond the discoloration, otherwise you'll have hard spots which can cause the shimmies.

**Martin Long** · 07-06-2006, 08:52 PM

I bedded them in as per instructions, but I think you are correct in saying the track work was a littile harsh for street pads, maybe I should have fitted harder pads for the day. I don't get any negative feedback when braking so I assume (bad choice of a word!) they will clean up in time, but I will give them a light skim anyway.
Brake fluid is also in question, I think the problem is a combination of the above two factors.
Change the fluid, harder pads and give it another go go go!!

**xsperf** · 07-07-2006, 12:09 AM

go with ceramic pads, like axxis ultimate or hawk or EBC greenstuff(<-- i dont know if that is ceramic)

nick_318is · 07-07-2006, 12:12 AM

Good pads and good fluid should make a difference at the track and help you to have less brake fade.

**c1apton** · 07-07-2006, 03:01 AM

Hate to be the messenger of bad news, but the "bluing" in your rotors is embedded heat stress. You "might" be able to turn them down far enough (highly unlikely)
If you plan on tracking the car you might consider seperate pads & rotors for street & track. You asking alot of either style to perform in totally opposite situations. Race gear is great for extreme conditions but not made for street conditions (longevity, high mileage, etc...) Alot of race gear is "sacrificial" and made to be used, abused & tossed.
A good brake fluid & a good set of stainless lines would work for both conditions.

**zeit00** · 07-07-2006, 02:38 PM

Quote:

Originally Posted by c1apton

Hate to be the messenger of bad news, but the "bluing" in your rotors is embedded heat stress. You "might" be able to turn them down far enough (highly unlikely)
If you plan on tracking the car you might consider seperate pads & rotors for street & track. You asking alot of either style to perform in totally opposite situations. Race gear is great for extreme conditions but not made for street conditions (longevity, high mileage, etc...) Alot of race gear is "sacrificial" and made to be used, abused & tossed.
A good brake fluid & a good set of stainless lines would work for both conditions.

Yep.. rotors got too hot..

**c1apton** · 07-07-2006, 03:12 PM

Just a sidenote about your rotors. If you do have them turned you'll see the extent of the damage. As the lathe cuts get deeper take note of the surface: If the heat has gotten really deep the "cutting bits" will literally vibrate and make a strange pattern in the "hot spot areas". If you see that don't bother any further cutting. Also have them cut at the slowest lateral speed (lathe movement right to left) for the finest cut you can get.