brakes

[xanthinic12]

ok i have a 91 gl yeah
i have a problem with brakes again
ok
i bled got all air out, no good
changed master cylinder bled, no good

whenever we bleed the brakes we get good pressure until we turn inthe engine it goes to the floor.
what now?

[SoCalZ28]

hm, make sure your getting enough vaccuum from the motor, i think it should be 18-21in/hg? correct me if im wrong. the other thing, often times the booster is not able to fully stroke the master, if you think youve got air in the master, take it off and bench bleed it.

[25Horseplay]

did you install the vacuum line from th B3 on the booster? There is a valve inline that you need for your brakes.

[xanthinic12]

did you install the vacuum line from th B3 on the booster? There is a valve inline that you need for your brakes.

yeah
but it was like this before the swap also
thanks for the replies

[25Horseplay]

You might need a new booster.

[FestYboy]

replaced master and there are no leaks?, pedal goes to floor when engine is running? most likely cause is air in the rear system, or massive leak at wheel andcylinder(s), but rulling these out, the internal baffle in the booster is probably torn causing excessive boost. test: lift one side of car (both wheels off ground), start car and apply brakes. both front and rear wheels should be locked up. If one of the wheels isn't locked up, it's not a booster issue. if BOTH the wheels are free, then you have an internal booster issue (not the baffle), replace booster.

[WmWatt]

Any sign of fluid leak under the car?