I recently installed my own version of the superduty trans cooler on my 93 4x4. I cut the line out from the converter to tie into.while it sat It constantly drained out fluid, I got 4 quarts before I hooked it back up but was still draning. If Im not mistaken this would be all from the converter. Seems between dropping the pan and taking the lines apart again you could drain almost all the fliud out. Any thoughts on this?

 

I'm pretty sure you won't get much more than half of the converter. The line nipples are above the pan, so the pan is still full. I think the converter holds 7 qts. Your only gonna get about 2/3 of the fluid out, but unless it's looking cruddy, that should be enuff. The good tranny shops still advise that is is better to do it this way than a power flush.