This morning I got in the car (chrysler concorde) which I had let run for about 20 minutes to warm it up as it is -18 with the wind chill today and I pressed down the brake pedal and it hisses like air coming out from under the pedal. If I press it to the floor, it stops. But if I press it and hold it pressed like 1/2 way, the hissing doesn not stop. I drove anyway and the brakes worked fine - just sound like air coming out every time I touch the brake.
Could it be because it is so cold? It didn't make this noise yesterday but the weather turned extremely cold overnight.........I am just afraid my brakes will go out while I am driving......