Contour Enthusiasts Group Archives Forums Modifications Zetec Maintenance To flush or not to flush, that is the ?

Ok, I've read through several old posts about draining the tranmission fluid. I want to change my current ATF with the Mobil 1 Syn ATF. According to my Chilton's book, you just drain the transaxle by removing the drain plug with a 3/8" ratchet. Then fill the transaxle with new fluid, start the car and shift through all the gears for roughly 5 minutes. Easy enough! But now I've found several posts saying to remove a line to the oil cooler and completely flush the system of the old fluid BEFORE you put fresh fluid into the transaxle. Why doesn't the Chilton's book list this as an option? And where is this oil cooler line located? Near the radiator? I really have no clue with this one. I've owned my car for about 36,000 miles and have never replaced my ATF. If I drain the pan and then run the car for awhile and then re-drain the pan, will this get most of the old fluid out or is it a waste of time and money? Or should I just save time and bring it to my local Ford dealer for a complete flush and refill (quoted at roughly $90). Let me know what you all think. Thanks!