you posted this on the wrong board, thats why no responses.
I would look at the rotors, too, as they might be at their service limit after 100,000 miles, assuming you got new rotors the last time. The pads themselves are easy and there is plenty in the archives.
Use the MB brake paste, the blue stuff sticks to the rubber seals too much.
You might also run into a bad dust seal, so check with your MB dealer and see whether they have that part incase of need, if this is your daily driver.