You do have a leak, vacuum leak in your master cylinder. Over time, the rubber seals fail and the pedal goes all the to the floor. If you pump it a few times, the seals create vacuum and your pedal is fine for a few times, and then it goes down again.
If you know how to rebuild the master cylinder, rebuild it. If not, get a re-manufactured one from your local parts store.
Sunday, December 14th, 2008 AT 6:10 PM