JimSmith has it outlined
I have to say that the brakes on the 108s have been great almost no problems.
the master muts be the cause -- the system is so simple that it must be it -- let us know.
Also must say the car looks very nice - the white 108 is just a great Mercedes.
I will also say that a total failure of the system is very rare -- one must remember that this system was way ahead of its time. I also would say that rebuild is easy in this car -- the calipers were designed to be rebuilt.