Hydro-Boost & Power Steering Problem

I've added Hydro Boost to my 90 Cherokee. Prior to adding the Hydro the brakes were terrible with the big tires.
Since adding the hydro I have been experiencing periodic hard steering but the brakes work fine.
I have a relative new pump (six months) in the system.
Any ideas?

Gardner

Are you using the matching power steering pump that goes with the hydro boost?
If not, perhaps the flow from the original pump is not adequate. I believe the hydro boost system has a pressure resivoir that provides 2 or 3 stops using internal pressure which may mask the onset of the problem.