[BMWCSRegistry] No brakes with engine on

[SPANLAB]

Hi list,

Can anybody please help diagnose my problem. I have recently 
overhauled my calipers and installed a new MC. I have bled the system 
and with engine off it is free of air and has nice pedal feel. 
However, when I turn the engine on the pedal sinks. The servo was 
perfect before I did the changes. I have the check valve with black 
part towards the engine.  I have tested the Servo for vacuum but it 
hold fine?  I have bled the MC and compensating valve in the rear. Any ideas?

Enrique