I have recently aquired a 2001 yukon xl and have been bringing it back to good health. It runs well and is now fairly solid in the front end but I find the steering to be much too light at highway speeds for my taste. The steering effort around town is about right but above 50 or so it seems to get lighter instead of heavier. This results in small deviations in direction that are completely unfelt in the wheel. I realize that these things are a bit of a sailboat in a crosswind but this is occurring all the time. I have read about changing the orifice in the PS pump but don't have any clear info. Can anybody offer a cure?