ok, then that's 40% new fluid per drain-and-fill, and a compounded total of 78% for three. So using 8 qts of new fluid you are still leaving over 20% old fluid in the system.

In comparison, a drain-and-fill followed by a cooling line flush should give you 90-95%+ new fluid using the same 8 qts.

 

For the flushing procedure, you should purge the disconected line (air pressure or oral pressure) to the reservoir, before draining the reservoir of old fluid. This will allow draining of old fluid trapped in ATF cooling lines.

For the very **** retentive, the procedure in the youtube videos used an intermediate flushing w/ Type IV ATF, before introducing the Honda ATF.

good luck

 

That video also blows out the old fluid from the cooling line AFTER refilling the reservoir!

 

OK sorry. I thought the predominant mixing point was at the torque converter. Guess those connections aren't as restrictive as I assumed.