i don't think i understand everything i know about the transmission flush for the 850 non-turbo......could someone please explain this.......????

i flush according to the Haynes Manual. I disconnect the return line from the tranz and insert a clear 3/8 inch plastic hose. next i drain the tranz by removing the plug on the bottom. i add 2 quarts, then i turn on the motor and catch two quarts, refill with two quarts and repeat this two more times. when i do it the last time the ATF comes out the same color as the ATF going in. i have only used 8 quarts...........THE QUESTION.......what is all the talk about using 14 - 15 quarts in the flush process to get a dilution factor. i thought clean ATF was clean ATF. do i need to use more??????

thank you for your response,

95850