B10 BiTurbo Brake Disc and Pads Replacement Thread

[BerlinThunder]

Originally Posted by puppypilgrim

I can now confirm that E38 750iL discs\rotors do not fit without modification when retaining the stock Lucas Girling brake calipers.

This was the part number I used:
E38 750iL 34116757756

The bolt pattern is fine. But the calipers touch the rotors. So he machined down the calipers for more clearance. Under extreme braking however, the caliper still slightly touches the rotors. Therefore, the mechanic recommended that the new rotor be machined down a little prior to mounting.

As I said, I´m running these discs for years and no probs. Also i didn´t had to go to the machine shop. It just fits.
I think different disc manufacturers have different production tolerances and therefore we have some that fit and some doesn´t
That´s a pity.

[Cor-Jan]

Originally Posted by puppypilgrim

The bolt pattern is fine. But the calipers touch the rotors. So he machined down the calipers for more clearance. Under extreme braking however, the caliper still slightly touches the rotors. Therefore, the mechanic recommended that the new rotor be machined down a little prior to mounting.

Same happened on my car.I was never satisfied with the discs from the beginning and had the alpina's put back on wich i'm still very happy with even after a lot of hard braking from high speeds.

[Gerg]

I'm pretty sure that Alpina used different style calipers on some cars. On the BT I used to own the calipers looked different on the right and left side. They were both Lucas Girling but looked different. That could be why some rub and others don't.

Greg

[bendeco]

As I stated in another thread, I believe I have M635 calipers on my B7TC. I have to use 5mm spacers so that the 16" Alpina wheels clear the body of the calipers. Somehow, I don't think Alpina designed things this way. I also have a set of 17" third generation wheels, and they hove no clearance problems with the present setup. I use M635 rotors, so I have no problem between them and the calipers. I suspect the Alpina calipers and rotors are offset a little to the inboard side, as opposed to the similar BMW parts...

[B10BT_Dream'n]

Originally Posted by puppypilgrim

I can now confirm that E38 750iL discs\rotors do not fit without modification when retaining the stock Lucas Girling brake calipers.

This was the part number I used:
E38 750iL 34116757756

The bolt pattern is fine. But the calipers touch the rotors. So he machined down the calipers for more clearance. Under extreme braking however, the caliper still slightly touches the rotors. Therefore, the mechanic recommended that the new rotor be machined down a little prior to mounting.

The fellow that did my "out of province" inspection performed a similar procedure on my car. I gave him a hard-copy of a much earlier version of this thread which he said was very helpful. He took the diameter of the rotors down by 2mm so they matched the Alpina rotors, then he machined the calipers by a hair. Next brake job I'll probably go with a Mov'it setup all the way around.

On another point, I found a hand scribbled note in the history file that came with the car. It reads as follows, perhaps it's useful:

-Discs: BMW 850 standard discs. Fit straight on, then machine 2mm from 1 side of caliper mount, then use spacers to push caliper back to standard if required.

-Uses brake pads with "EBC Red + Green"

From the note it appears like this tip came from the owner of B10BT No. 0303, who I believe is also a member here.

[puppypilgrim]

Here is one other idea obtained from the Yahoo E34 M5 mailing list:

Contact Jeremy at Ireland Engineering
Their E34 M5 kit uses 850csi rotors with Corvette C5 calipers front and rear. Much cheaper than other kits out on the market, and the piston area of the calipers matches the proportion of area front to rear of the E34 M5. Also, the front pads have more surface area. I've been using this setup for quite a few years and it is much much better than the stock setup. They fit fine behind the stock 17-inch wheels.

[quattroboy]

Puppypilgrim and all;

I'm in the middle of a front suspension project and noticed my rotors are quite thin. They measure about 28 mm thick.

I was looking in the Alpina manual and they spec 332x30, not the 332x32 as mentioned in this post. Has any tried the 750iL/740D rotors to see if they fit?

I uspect the proper size is 332x30 based on my rotors, I can't imagine them being 4 mm under.

Thanks,

Sean

[puppypilgrim]

I used the 750iL North American part number 34 11 6 757 756 discs and they fit. However, my mechanic needed to machine the rotor or the caliper a little bit for it not to rub. I can't remember exactly which part needed to be machined. I paid USD $82 each disc from BMA AutoParts. If you find a better deal, let us know.

I also used the Akebono ceramic brake pads for the Mercedes spec'ed at the start of this thread by buying them from LOWDEN (W.H. Lowden Inc.) in Vancouver. I am content with the Akebonos. Much less brake dust and works for my kind of driving.

[Ferrari-Bmw]

Later this summer i think i will by the BMW 740//750 E38 front disc

and change them for my oem BT disc,,

I use ATE ,,,,,,,,,, W140 600 M-B pads,, and they are fine ,, but there are sometimes a small vibration when braking,,,,,,

I was thinking to take the disc off and give them to a lathe and try to take the distance that needed to get the vibration out,, the discs are driven max 20.000 km i think,, and pads 10.000

[m5 killer]

standard brakes for the bt are a bit dated now and it would be wise for people who are looking to keep their bt to upgrade brakes and change caliper and pad set up alltogether, you will all benefit in the long run