[dre99gsx]

Can anyone here confirm that they:

A- get a high and firm brake pedal when engine off
B- brake pedal slowly sinks to floor with engine on when you push and hold on it for ~10 seconds?

It seems this may be normal, and I want to rule out something else. I just replaced the Master Cylinder, so chances that I replaced it with a faulty one seems odd.

I tested this by having the engine off and applying vacuum directly to the booster (using a vacuum pump), and same thing happened. I suspect the booster is providing so much assist that I must be overpowering the master cylinder seals and that is what causes the pedal to slowly drop. Seems like this may be normal?

ALSO

Those of you with BBKs on Z4M, can you find out how much room you have between your rotor and the tie rod/lower ball joint/splash shield? On my setup, I have about 2mm. It's VERY close. I'm suspecting there may be a chance that under steering load, possibility that my tie rod/balljoint may be pushing on the splashshield, which may be pushing on the rotor causing it to go out of parallel with the caliper. It's just a hunch, but I may attempt to design 1mm spacer between rotor hat and hub, and also on the caliper mounting bracket.