power steering problem

i have a 89 silverado 1500 with stock 350.
My problem is with my steering, after the truck sits for an hour or so, when i go to turn right it is verry stiff. when i first get in the truck and start it, if i turn al the way to the right, it will turn fine for the rest of the time. but every time i get back in the truck after it sits, it is stiff again.
anyone have any solutions/suggestions??

Thanks in advance for any help,
Wade

if the problem only occurs when turning one way then you have a problem internal to the steering gear.

then why does it stop doing it after i turn the wheel?
thanks for ur help

something in the spool valve is going wrong, i would suggest replacing the gear

how much is it, and how hard to do? i dont know much about it