Hard Brake Pedal - Help Please

[Sompin2do]

90 GT Stock

R&R Master Cylinder about a week ago.
Bench Bled, then bled lines.

A couple of days later found out I needed new pads. Removed MC cap so calipers could be compressed. Put the pads on and closed the cap.

Brake pedal is hard now. Should I have bled the lines again? Any need to pull the MC back off and bleed again on the bench?

Thanks!

 

[Sompin2do]

Almost forgot. I can hear air when pressing the brake pedal. Thanks!

 

[393Bird]

Sounds like you have power brakes, and the booster has a internal leak, that requires it to be replaced. It most likely runs a little rough, or changes rpms slightly when you press the break pedal. If so, the booster is shot.

 

[kck6894]

Sounds like you have power brakes, and the booster has a internal leak, that requires it to be replaced. It most likely runs a little rough, or changes rpms slightly when you press the break pedal. If so, the booster is shot.

I second that. Sounds like you have a booster problem of some kind.

 

[Sompin2do]

Is there a good test I could do to verify that it's the PBB?

It doesn't run rough, but while sitting at a light earlier today, it did surge a bit.

I did a test that I found on Autozone.com that says "start the car and let run for a couple of minutes, shut off, apply normal brake pressure. If pedal stays, PBB probably ok, if it rises, PBB probably bad."

Does that sound legit? The pedal stays the same.

Thanks again,
Mike

 

[Shakerhood]

The pedal should get hard AFTER you shut it off the car if the Booster is good.

 

[Tony90hatch]

Right after you shut off the car the booster should still have vacuum in it. So after the car is shut off, pump the brakes a few times. It should be soft then get harder.

 

[dre0011]

check your main vacuum manifold its located on the driverside firewall right above the intake manifold...it is a small plastic manifold with about 4 hoses coming out of it...they are labled b/c...a/c...and somyhing else. check to see that the hose labled b/c id connected and also check that the main line to the intake is connected to this manifold also...the main line id under the back of the upper intake manifold. hope this works 4 u..