Hissing sound near rear tires, what could it be and could it cause brake failure

What is your question?

About a month ago my car started making a loud hissing noise near the rear tires. I had the tires checked but there was no leak. It made the noise every time I would park it after driving it even a very short distance so I stopped driving it all together. I was required to drive it yesterday due to a minor emergency and the brakes went completely out and stopped working. I checked the brake fluid and it was still full and there seemed to be no visible leaks in the lines. Also after the brakes went out and the car was parked there was no longer the hissing noise I was hearing whenever I parked. Could the noise and brake failure be connected and does anyone know what possibly could have caused the brakes to fail without leaking fluid? Also the ABS light has been on and off since I got the car 3 months ago but I didn't see it as too big of a problem since I have driven other cars for a long period of time with the ABS light on.