85 gt with brake pedal issue

[jackass#1]

got a 1985 gt convert. when brake pedal is applied you can hear a rush of air. cant hear it under the hood just at the pedal. is that normal? didnt realize it until a month ago.

[351wStang]

As long as you cant tell a difference in feel its probably fine. You are just hearing the vacuum in the brake booster.

[jackass#1]

sometimes it is hard to stop car. and others its fine.

[bugman742002]

you may have to replace the booster.

[Davescort97]

There may be a check valve between the brake booster and the vacuum source. The way to check it is to remove the brake booster hose and try to blow air through it both ways. The air should only flow toward the engine side of the hose. If it flows both ways or neither way replace the hose and check valve.