where does the leak look like its comeing from?if its from the pitman arm there is a seal inside there that can be replaced.rent a pitman arm puller and remove the pitman arm.now look up inside where the shaft goes into the box.you will see a snap ring.remove the snap ring.now fire the beast up and keep turning the wheel lock to lock.when its at full lock hold it there with a good amount of pressure on the wheel.the seal will eventually pop out.i believe there are 4 pieces to the seal.you should have a dust seal,oil seal,and 2 steel rings.now slide all the new pieces up inside the box and replace the snap ring.the seal will have instructions on how everything goes back in.
the groaning sound is most likely from air in the system.you may never get rid of it,even with a new box and pump.fords powersteering systems have always had a whine to them.i ask mine if it would like some cheese and crackers to go with its whine