Question for everyone. We have an '01 V70 T5, 93K on it. After letting up the brake pedal, we get a hissing sound. Sometimes, but not always. And some times it happens for a few seconds, other times longer. There seems to be no correlation between if it happens and for how long to how hard/long I depress the brake. It doesn't seem to affect the braking at all and it's been happening for some time actually, I'm just now getting around to asking. <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/smile.gif" BORDER="0"> Happened before and after I did the front brakes as well.<p>Any thoughts?