Brake issues

[Brian B]

I am having some issues with my brakes on my 79 Hurst. End of last summer was braking and pedal went to floor brake light came on. This happened again this year. I replaced the control valve. Fluid is full, and no fluid leaking. Rubber vacum line and metal line to carb have no leaks as I can see. When car is in gear is when it goes to the floor and brake light comes on. In park or neutral brake feels fine no brake light comes on when brake pedal is pressed. Thanks any info would be great. Brian

 

[tkruger]

I had a similar issue where the booster was loosing vacuum. The diaphragm in it had gone bad. Is there a hissing when you press the petal?

 

[Brian B]

I had a similar issue where the booster was loosing vacuum. The diaphragm in it had gone bad. Is there a hissing when you press the petal?

Yes there is a hissing sound when pressed.

 

[565bbchevy]

Start with checking the check valve and it's rubber seal on the booster first,

 

[Brian B]

Start with checking the check valve and it's rubber seal on the booster first,

Replaced that yesterday