1997 GMC C/K PICKUP User Comment / Complaint

I own a 97' gmc z-71. i've been having problems with the steering on my truck for the past 3 months. it gets in a bind when turning and i lose my power steering part of the turn and then i regain it coming out of the turn. i have a friend with a 96' chevy tahoe 4x4 that has the same problem, and another friend with a 98' chevy silverado that has come across the same problem, almost resulting in a crash. we all have changed our power steering pumps and still have the same problem. i also have trouble turning my wheels when sitting still or at slow speed ( i run 285/75/16 radials) and it causes an inconvenience in tight turning or in a parking lot. i hit a car in the rear because my truck couldn't turn fast enough in a local store parking lot.