well ever since i've had my car i've noticed that when i press the brake pedal down, not mashing it down, but firm enough to stop the car (or keep the car stopped at a light) there is a hissing sound that comes from down there. the car is a 93 and has been converted to a 5 speed. i'm wondering if my brake booster is going out or if anyone has any thoughts?

 

It's a normal noise. If it does it continuously and the pedal get stiff and the brakes are hard to stop, then the booster is bad.

 

+1 mine did this and was planning to fix it but........