Hi:

Re: 1999 Grand Prix 3.8L

Here's what's happening:
  • Brake pedal goes to the floor, no resistance at all
  • No leaks under car
  • Reservoir was empty; filled it, pumped pedal and level dropped, but still no visible leaks.


From what I have read, this is most likely an issue with the master cylinder seal, and fluid disappearing without leaks means that the fluid is leaking into the vacuum booster.

Question: Does this mean I will have to also replace the booster when I put in the new master cyl?

Thanks!