I added a hydroboost unit on my sons truck, I have used them before and love them, This time I didnt use power steering. If you uses a hydroboost without power steering DO NOT plug the pressure hose side for the steering box! The hudroboost booster does not bypass. you can burn up a pump. We didnt but found this answer quickly. Research on the subject said to use the steering box side as an extra return. We did this and its working (yard driving) so far. I was surprised that the fluid pressure from the booster to steering box is not very high. If anyone here has done this please chime in. if you plan to do an install like this you still need the PS pump with dual returns.