Hi there. Everytime I hit the brakes in my car, with the radio off, I can hear a hissing noise that is constant until I take my foot off the pedal. The pedal feels great, I have never had a problem stopping, as far as a hard pedal goes. I would think that the booster itself is going bad. I started to notice it in the beginning of the summer. The brakes have felt the same ever since. If I was deaf, or always had the radio on, I would think the car was fine. replacing it is not a problem, but I dont want to replace it if it is not bad. one of my old bosses told me that some cars just make a hissing noise. anyone have any suggestions on whether or not I should replace the booster?

 

sounds like the booster is fine, the hissing you are reffering to is more than likely rf noise going through your speakers. If you install a ground loop isolator it should solve it. I don't think it has anything to do with your brakes if you can't tell a difference in them.