I got in my car in a rush today, started up fine, went to drive off and it felt like the brakes were on. The car wouldnt roll and had no momentum. I'm sure some of you will probably realise already that I actually had a completely flat front tire. I didnt figure this out for another few minutes when I went to check . Anyway, the point of this post is that when I put my foot on the brake it hissed at me. I've never noticed this before and assume its normal, I just want to know why?