Mine is doing the same thing with hard left turn only. Recently discovered p/s return line had a big crack. fixed that and now it is hard to make left turns. Eases up after the car is driven for 5 mins or so. p/S fluid level is great. not loosing any. Looks like i need to check TCS fuse and if its not that then consider changing Rack and Pinion? Or is there another simple fix to try?