Greg;

Sorry to be picky, but if you're not moving fluid out the bleeding nipples, you are infact not bleeding the brakes...only attempting to bleed the brakes!

...and just how are you going about your attempt to bleed system...did you back the bleeding nipples out far enough to open a fluid path?...are bleeding nipples plugged in any way? as other poster suggests...was the replacement master confirmed to be exact in fit and form function?...when getting "exact replacements" don't take the guy behind the counter's word...he only know what "the book" tells him, and "the book"'s been wrong only about a zillion times!...have any other changes been made?

Interested in your responses!