Originally Posted by bobtent
If i shut the engine off and hit the brakes, i have normal brakes until i pump it for a little bit. So that right there rules out that i have a booster issue..Is there anyway to check the master cylinder? Also, is it normal for the car to be at idle and while the car is idling i can have my foot on the brake pedal and while my foot is on the brake pedal, i can just feel the pedal go down more???
99% of the time, if your pedal drops with very light pressure, it is an internal leak in the master cylinder.
Do this test:
with the car idling - push really hard as in panic stop. If the pedal is firm and doesn't move in 3 or 4 seconds, then release the pedal. Now, just rest you foot on the pedal with barely the weight of your foot.
If it slowly goes doen, the master cylinder is faulty.
If not, then have the brakes blead properly -ie: left front, right rear; right front, left rear. This goes for ABS or non-abs cars.
Be sure to use (or the shop does) a clear plastic tube on the bleader, into a bottle with fluid, so that there is no possibilty of air going back into a wheel cylinder.
You should do the bleed cycle on the fronts at least 5-6 times & the rear 10-12 times to ensure that you are getting fluid fully through the system, and make sure that the fluid level in the MS doesn't drop too far during it.
Once you've done these two proceedures, if you still have problems, it is time to pull each wheel to look for caliper problems, either leaks (most likely) or seized.