B10 BiTurbo Brake Disc and Pads Replacement Thread

[quattroboy]

Originally Posted by BerlinThunder

Aftermarket 740d Sport-Discs from Zimmermann do fit pretty well, without maching the calipers. S600 Pads from EBC do fit also. But none of the mentioned wear sensors work. I tried nearly 15 sensors.

Hi Alex;

Thanks for the information, I have the discs on my bench and will test fit them when I get my calipers back from the rebuild shop. I thought I might have to machine 1-2 mm off the outer face based on my side-to-side measurements, but I'll know for sure when I mount the calipers back on.

Did you try a wear sensor from a MB S600? I have one on order ($1.00!) and I'm going to try them. I'm assuming it will fit into the pads and I'll splice in the proper electrical connector at the other end.

Sean

[puppypilgrim]

I have not found brake sensors that work either :-(

[puppypilgrim]

Great Quattroboy,

I'll have to bring some beer your way so you can make me two!

[BerlinThunder]

Originally Posted by quattroboy

Hi Alex;

Thanks for the information, I have the discs on my bench and will test fit them when I get my calipers back from the rebuild shop. I thought I might have to machine 1-2 mm off the outer face based on my side-to-side measurements, but I'll know for sure when I mount the calipers back on.

Did you try a wear sensor from a MB S600? I have one on order ($1.00!) and I'm going to try them. I'm assuming it will fit into the pads and I'll splice in the proper electrical connector at the other end.

Sean

Sean, the MB Sensors work with 1 wire. BMW ones need 2 of them. The MB sensors fit but you need to re-wire the whole thing. One of the BMW wires should go to ground (chassis) the other one to the MB wear sensor. That probably should work. What about ordering OEM parts from Alpina? Shouldn´t be expensive.

[quattroboy]

Originally Posted by BerlinThunder

Sean, the MB Sensors work with 1 wire. BMW ones need 2 of them. The MB sensors fit but you need to re-wire the whole thing. One of the BMW wires should go to ground (chassis) the other one to the MB wear sensor. That probably should work. What about ordering OEM parts from Alpina? Shouldn´t be expensive.

Well, just received the MB sensor and you are correct, its one wire. It will not work as I've determined that the MB brake sensor has a plastic sheath around the conductor and when it wears, it completes a circuit to ground triggering the warning light.

On the BMW, its the opposite. The sensor is a loop and is a completed circuit when good and when the wire breaks, the continuity is lost and triggers the warning light.

The only way to make the OEM one work with MB pads to either modify the sensor or modify the pad. I'll figure out something or worst case insert a jumper in the circuit to "fool" the warning light.

By the way, the original Alpina sensor is a standard BMW part.