It isn't just reserved to us X53ers either. I've done some searching and it plagues more people than you can imagine. Now, I'm not an idiot, but I really can't see what I did wrong and a shop who has been doing this for 25yrs can't seem to fix it or explain it either. It's nuts, I agree. It should be as easy as this video below, but alas the Germans and their complex ABS/DSC/whatever-else systems tend to complicate things a bit. I laughed when I watched this video. Can you imagine doing the X5 master like this and it working?
Fixing A Sinking Brake Pedal
But check out some of these various threads for some head scratching. All over the map.
Porsche issues
Sinking brake pedal - Rennlist Discussion Forums
More pedal sinking - pads this time?
Changed the brake pads - now the pedal sinks in
More bmw mysteries
e39 sinking brake pedal
See post #18 and #20. Bloody hell
http://www.xoutpost.com/bmw-sav-foru...s-floor-2.html
See post #2 and the pdf it references - these brake systems are so simple - unreal
Brake Pressure Sensor (DSC/ABS/BRAKE Trifecta) - Bimmerfest - BMW Forums