I have a '93 and a '97 Taurus SHO. Both have factory PS coolers. The '93 had over 120k on it when I got it. The PS fluid looked like coffee. It took almost a gallon of ATX fluid changed over a 3 month period to get the system clean enough to keep the fluid red. On the '97 I changed it at around 50k and it too was brown. Now I just do the turkey baster thing once a year. I also run a Magnifine filter on the '97 PS line.