I keep getting continous pedal vibration after I did the brake upgrade from the NX 2000. Basically after I have the rotors turned and install new pads, the pedal is fine. Then after about 3 months or so I start getting the vibrations. The rotor is well within specs. I bled all of the air out of the lines and that didn't help. One thing I remember doing is putting the same valve (the two long cylinder looking parts on the master cylinder that the lines connect to) from the old master cylinder (the one that was designed for the rear drums and front disk) to the new master cylinder (the one from the NX 2000). Can that be the problem; if not what can the problem be?