I just did a flush this weekend to try and recover from a leaky radiator/tran cooler last week... 20-24 quarts of fluid until it ran red out the return line. Lots of starting/stopping but not too bad, and didn't take all that long to do. I started by draining pan, filling 3-4 quarts, then running for a few seconds, refilling, repeating... etc
a remote start made this much easier, as I could start/stop while watching the return line
had a friend helping, but was still easier
I plan on running another 12 quarts through it next week, just to be sure, and in the summer I want to drop the pan and replace the filter as well... any one have experience with the fill/tube being an issue when removing pan? I have heard it commonly breaks off, is this true? (MI truck = more salt/rust)