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SharkmanBMW
09-06-2005, 02:30 PM
Please forgive me for being mechanically un-inclined these days...
one month ago, I had my indy change pads and discs all around.
We used Axxis ceramic pads and Zimmerman discs.
During break in, it seems that the brakes got too hot, the pedal never got soft, BUT the rear discs are blueish and there is a shake when gently braking at high speeds - sometimes!

It feels like the front discs are the ones that are off, but I was told the blue is bad on a disc!

My indy also just told me that the zimmermans they sell at the dealer and those sold aftermarket are not exactly the same, dealer is more heat resistant.

That same day, he also installed a new upper control arm, so I was originally unsure if the problem was that or brakes....
What the verdict on blus discs???

Jose
09-06-2005, 03:27 PM
You should not be too worried about blue discs normally unless they didnīt get the chance too cool off while running the car. In your case the quality of the disc seems very doubtfull as the disc should not turn blueish while breaking in. It sounds like the material quality is not up to the standards it should be. If the rear discs are warped, the shaking effect can be far worse and especially louder than if the front discs would be the warped ones.

Actually, there has been no real quality replacement discs available the last five years other than original. Original ones receive a special factory heat treatmentand are made of higly selected materials.After market discs are far from close in being the same discs, especially those fools from Zimmermann. We replaced many Zimmermans in our shop by originals and all problems dissapeared. Itīs your choise.

SharkmanBMW
09-06-2005, 03:49 PM
So are you saying the rear blue discs, could make the whole car shake including the steering wheel???

I assumed the fronts would have to be the ones making the steering wheel shake....
Thanks for your very helpful input.

632 Regal
09-06-2005, 04:13 PM
according to all that brake bed in stuff I read the disks are what you break in first, you havent done it correctly if they DON"T turn blue. After several heat cycles and a complete cool down you do the pad bedding (why didnt they bed already?). You are NOT supposed to stop completely during the process untel the last step of a 20 minute cool down Then its OK to stop. Ill look for the link.

K, heres lots of readin for you...
http://www.stoptech.com/technical/

SharkmanBMW
09-06-2005, 04:21 PM
I did all that, the box I had said 1/4 mile between stops and go from about 50 to 10 mph and start again.
One mechanic saw my rears at the tire shop and freaked, saying that they were scrap because they were blue.
Now I just want to know if I should swap the fronts or rears to fix it!!!

The rears are blue, the fronts are normal.

Can turning fix this? I don't really want to put more $$ where I just did a month ago!

But of course, I will
!!!! :p

Karl
09-06-2005, 04:24 PM
I blued the front discs on my old 528i (e12) at drivers' school. The discs were far from new at the time, and they did not warp. And they lasted quite a while after that, including an autocross season and a few more track schools.

The only way to tell for sure if the disc is warped is to pull the wheels, spin the disc, and check for runout.