Is my booster shot? When the car is off, I have good pedal movement. Right after I start the car, I can see the pedal being pulled to the floor- almost like it is being pressed. uzzled: It only takes about three seconds, and the pedal has been sucked down about 1-2 inches, and no longer has any travel worth a crap. I don't think this is normal. Does this sound like the booster?
Could be a ghost. I've seen some cars where the the pedal moves a tiny bit when you start, but still has plenty of travel. If it were the master cylinder it would go to the floor too easy, but I think you'd have your foot on it. Maybe the master cylinder is really shot - but I'd guess the booster too.
To test the booster, pump the pedal several times to exhaust any stored vacuum. then apply pressure to the pedal, and start the engine. The pedal should drop. This indicates a properly functioning booster. First thing I would do is check fluid level, and each wheel for a leak. Then bleed the system. If it doesn't improve, the master cylinder is probably shot. Everytime I've had a master cylinder go, the major symptom has been a dropping brake pedal. You'll be sitting at a light with your foot on the pedal, and suddenly the pedal just drops away from your foot.
