I'm at a loss with a brake problem on my 300d. I lost brakes a couple months ago and since there were no signs of broken lines or anything like that I assumed that it was the master cylinder. I replaced it without bleeding the brakes. The brakes were better still with quite a low pedal but the vehicle was stopworthy. So I finally got around to bleeding the brakes to no avail. Still a low pedal. Also, when you pump the brakes to get a hard pedal, it's almost like the braking force is exponentially decreased.
Brian