My PS is not working correctly - it seems to only work when turning right (and I need to turn as hard as I can to turn the wheel left, I get no assist at all and the pump loudly groans).

I understand that there is some valving that directs pressurized PS fluid based upon direction turned. Is this all self contained in the PS rack? I don't want to replace the rack just to have the problem persist.

Any help is greatly appreciated!