I have an old 300td, and untill reacently have not really had much problems with the Brake system. I have had vacuum problems befor leading to Shifting and Locking Problems, and I fear that a NEW vacuum problem is now causing problems with my brakes. So when I go to stop the peddle will depress right to the floor givving little to no stopping power, and then i must "pump up" the resistance of the peddle by pumping the brake, hence yeilding more stopping power. Now I Spent all weekend trying to fix this problem by replacing the master cylinder with a used one off my parts car, and to no avail it did nothing, and unfortunitly i belive the problem to be getting worse. So there you have it, you know what i do... I havent checked the brakepads, but they were replaced just this summer and I dont beleive to have ever experiancing this when the brake pads needed to be fixed in the past. Thanks in Advance- Dave