Roy,
It is important that the return from the power steering box is going through the long side of the Tee, not the right angle portion. You may have an obstruction in the unit, clearances in the valving are very tight. this product really cleaned my system up and it works perfect with a Tee-
http://www.lubegard.com/~/C-198/LUBE...uid+Protectant
You may want to contact Paul, he usually surfs this site often. He will straighten it right out. What pump are you using?
Rich