power steering problems

ok there is a new pump in but it still does the power steering wine, even when the truck is at a stand still (not turning the steering wheel). What do you think is wrong, is there air or something i have done the lock to lock thing. what is the best bolt on power steering pump. 90 xj np242 4.0L laredo aw4, What should i do???? Thanks

If its a Fenco or Atasco pump its prob bad