master cylinder vaccum booster

[Mike Guenther]

I have a couple of vacuum boosters with various issues and want to know if I should throw them out or if they are O.K.

How can you test a vacuum booster to tell if it is working properly?

Should the seal around the shaft that pushes into the master cylinder be completely tight or does it release some air when the pedal shaft is pushed in?

What if it is making a crunchy sound as the pedal shaft is pushed in? (yes, chunchy!)

When the motor is running the brake pedal is pulled to the floor. Is the booster bad?

Thank you for your input on this subject.
Mike

 

[kbailey]

Okay, I see no one has responded. While I do not have answers for you, I will ask...how much for a new one from MazdaMotorsports? The brake hydraulics and pnuematics are areas I don't mess around trying to save money. My friend lost his booster at Summit Point in his 1st gen RX-7 and ended up in the gravel at high speed. I lost a master cylinder on my street car once with no warning...80 miles an hour onto an entrance ramp with no cage around you will tend to make you very careful with your brakes in the future.....