Get yourself 2 quarts of
Mobil 1 synthetic ATF or
Redline D4 synthetic ATF.
BOTH are dexron 3 fluids. Get a turkey baster or better yet a "
battery bulb" and suck out the PS res.and replace with the fresh ATF- do this drain/fill procedure after every time you drive the car until you go through the 2 quarts of fresh ATF {should be 7-10 procedures total to use up the 2 quarts}.....your fluid should then look like new and to maintain this level of freshness,repeat using 1 quart atf on an annual basis for as long as you own the car{pretty cheap and easy preventative maintenance to protect a multi thousand dollar rack/pump/lines system} . following the above procedure I currently have 271,000 miles on my original rack and pump on my q45,not bad for a yearly investment of $7-10 for a quart of full synthetic ATF
purchase 2 quarts of Mobil 1 or Redline full synthetic gear oil {$10-12 per quart} and bring to your local mechanic/shop for them to use for a drain/fill of differential {my tech charges me $20 labor to do procedure using my fluid while car is on the rack getting an oil change} repeat every 30,000 miles for optimum longevity of differential.