Stiff steering 98 Passport

I need help... The steering on my 98 Passport (198,000 miles) is very stiff, almost like I don't have power steering. Sometimes it feels ok but 90% of the time you have to turn the wheel with both hands (no one handed turns esp during town driving). Not sure if it's the Rack or the PS pump. I don't know squat about PS steering. What is interisting is as the fluid gets lower (due to a slow leak) it is eaiser to steer.

FYI.. I've had the balljoints and the front axels replaced, both repairs made the steering eaiser but not by much.

I've run SEAFOAM transmission additive in the PS resivior to clean it thinking maybe I have a valve stuck or lots of gunk to clean out but so far I've only seen small particles comming out during the flush. The fluid was old looking when I bought the truck and I have since added new fluid after the flush.

Has anyone else had problems like this? Thanks in advance.

You could have an outer tie rod trying to seize up on you. When you jack up the front of the truck, is it still hard to turn the wheel? If not, I'd suspect power steering problems like a kinked or plugged pressure line. If it is still hard to steer, check out your outer tie rods.

I'll check out the turning capacity in the next day or two weather permitting and post results.

I never got to put the truck up on jacks as suggested since it got cold and snowy. However I did notice that the sterring was easy to move with a few fingers when the truck was on solid ice and packed snow. So I'm surmising that the pump is bad. Picked up a new one but just waiting for the temp to get up and the snow to melt.

I'll report on the results when the pump is replaced.

Update:

Got the new Pump on this afternoon and the steering is not 100% fixed. The power assist is much more consistant across all driving condtions but I still have to use 2 hands at low speed (parking, backingup, ect.). This makes me think to look at the Rack or the lines. I don't think the lines are blocked but I could be wrong..

More updates when I can post em.