Today I changed the transmission fluid in my 2002 F250 with the 4R100. I followed the proceedure that many of you do. (The one by Mark Kovalsky) I don't understand how I know how much fluid I have in there. The first thing I did was drain the pan. Then I put 7 quarts of new ATF in. Then I disconnected the cooler return line and started the truck, cycled it through the gears and ran it until there was air in the line. Then I put in 6 more quarts. Then I ran the engine again until there was air. I put the cooler return line back onto the pan. Then I put 6 more quarts of ATF in. I don't understand how I have any more than 6 quarts of fluid in my transmission. If I run the pump each time I put the new ATF in. Is there some fluid that stays in the lines or the coolers or the torque converter even if it is pumping air? I drove the truck home (about 15 miles very gently). Then I let the truck sit for about 3 hours and there is red all over the white part of the dipstick. I can't tell if it is overfilled or what is going on. I am very confused as to exactly how much fluid is in my transmission now. I wish I would have measured how much came out because I know how much went in!!! Thanks for the help!