94 GMC Back Brakes

My husbands truck will go in reverse but when he presses the gas to go it locks up and won't go. Like the rear brakes are sticking. After he messes with it for awhile it will finally back up. Does anyone have any ideas.

Welcome to AF, jack it up and see the wheels are locked, if so suspect parking brake mechanism or something internal. No mention of forward?

It works fine going foward. If you don't mind me asking if it is one of theose things how much are we talking?

My husband knows how to do a lot of things with vehicles his father was a mechanic. I was just wondering if this is something he can fix himself