I have a 2003 chevy tracker the steering wheel is getting harder and harder first thing I drain de system completely and refill it with fresh power steering oil the steering back to normal after three days the problem is back I repeat the same operation every thing was fine again but three days later the same problem again . I need some help

 

I have an '02 Tracker with stiff steering and found that the u-joints were dry. No grease fittings so I soaked them by spraying them with WD40 and everything else I had on the shelf and they loosened up. There are two of these joint the bottom one is hard to see and spray, it was the one that was causing the bulk of the problem.