I have bought and installed CPP's 400 series power steering box. After starting the engine and backing it out, the steering is not smooth as I turn the wheel. At one point it is very hard to turn, then after that it is very easy to turn, almost like the wheels aren't on the ground. This happens when turning left or right.

This box is in a 47 Ford Coupe with a SBC using the type II pump. Prior to installing this box, I had a 605 box installed. The 605 had leaks and occasionally stuck. Not good. I was hoping this box would solve my problem.

Does anyone have any input on what is causing this problem?