I did a search and no one else has had the same problem Im having. I didn't realize it till I had to slam on the brakes and the car gradually slowed and pedal just got hard. The car has had the vacuum conversion done to it. I went ahead and added a vacuum resevoir and I still have the problem. At slow speeds it seems to do OK, but if I have to jam the brakes, the pedal just gets hard. Any ideas? 
