Booster or leak or something else
I am hearing a hissing sound inside of my car, when stepping on the brakes and just sitting still. I have been told that it may be my booster. I am a little confused. After googling this, experts state that if it was your booster, your brakes would be hard. They are not hard. They are more spongy and it feels like I do not have the support of the back brakes. I have read that it could be the line or something called a dual circuit sensor or switch. I have also read that if the back brakes need replacing that it could cause the sound that I am hearing. You know how you let out a breath after you are so tired? That is what it sounds like. I am tired of people trying to just make money off of you, when it could be something simple and easy to repair. Please give me some feed back. 2001 325ci BMW, I hate this car with a passion. Would not buy an 2012 or less either. They should be sued for making such a car.