rock hard brake pedal … off and while running….

[Jon C.]

just got a 2002 Ford Taurus Sel and the brakes have been fine. then I noticed my pedal was extremely hard for a moment and normal.. about 5 mins later the pedal was again extremely hard and still is. weather the car is running or off..

Here what ive done so far:

Very first thing i did as check the fluid. it was pretty low… 70%-80% empty. Refilled

1. Checked for vacuum. No gauge but there is tons of “sucking” when i remove hose from booster check valve.
2. tested check valve. I CANT blow air into/through it. i CAN suck air through it.
3. With car off, i pushed on petal then started car. PEDDLE DOESN’T MOVE AT ALL

i can stop the car if i really push hard on pedal, but peddle doesn’t really move…

all the info i find only to check booster is to pump brakes with car off and keep pressing while starting the car and the pedal should go down. But since i cant press the pedal at all im not sure what to think.

And even after removing booster vacuum hose the pedal was still solid..

i just don’t want to change the booster and have it not be the issue.

Any ideas? Any other checks i can do to determine the issue?

Topic

[Richard Kirshy]

Suggest using a vacuum pump and check to see if there may be a leak in the brake booster.
If that checks out good, might look for any binding or stuck linkage with the brake pedal to the booster.
Might also check to see if the master cylinder is binding.
Side note:
If you were that low on brake fluid and there was no leaks.
It would be wise to do a brake inspection on all 4 wheels.

[Author]

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