Originally Posted by JimBlake
Sounds like something is seriously wrong with the spool valve (part of the rack). It's constantly directing pressure to one side of the rack instead of 'turning it off'. I'm betting you need a new/rebuilt rack.
If the PS pump has it's own belt, that doesn't drive anything else, then just take off the belt. If that gives you normal steering (except for the muscles) then get a new rack.
100% agree. I was thinking about spool valve but I couldn't get how it's comming back to the center. Anyway it doesn't worth to repair the valve.
Go for a new rack.