When you drain the system, I assume you have the front of your car off the ground. Do not start the car, just cycle the steering wheel lock to lock slowly while one of the hoses (lowest one ) is disconnected. The back and forth will pump the rest of the fluid/gunk out of the steering rack. Then go purchase 3 or 4 bottles of the clear power steering fluid (I believe Volvo sells it) go by a parts store, I believe I use the Prestone brand. The clear fluid is better formulated for power steering systems and reconditions the seals (that's what I've been told). All I know is that I had very hard and bumpy steering in my wife's 93' 940T and thought it might be the rack. I tried this method and the steering felt like new within a couple of days. Let me know if it works. Good luck.