A little info about the truck would help...

I would first make sure everything is cleaned out **REALLY*** well. Pull the back drums and clean it out with water first then some brake cleaner.

I would also check all your brake lines. While it's never happened to me, I would think the force of being pulled out could have bent/cracked one of your hoses or metal lines, and you have a small leak. Check first around the wheels, and trace the lines up.

Have a buddy step on the brakes while you crawl around and see if you can find the source of your "hiss". Prolly find a small leak there.

good luck

Erik <img src="/forums/images/graemlins/cheers.gif" alt="" />