mrfixit is exactly right, you have to bleed theses from the bottom up, and it also helps to bounce the pedel while doing it too. I recently replace a defective M/C on one of these, it was only a few months old, I realized that the M/C was defective when I tried to bleed it as described, and I couldn't get any fluid to flow up past the master cyl. Also I would advise to never push the pedel all the way to the floor until the system is fully bled.