the way I do it on my 2000 E320 (drain on transmission pan but no drain on torque converter) is

empty the pan from the drain plug - remove pan and install new filter, install back.

fill new ATF in whatever quantity you drained out from the pan.

undo the return line at the radiator cooler and put it in a bucket or jug marked in qts (slip some hose on it to guide it)

start engine and let it pump out 2 qts - shut off engine, fill 2 qts fresh ATF in transmission, start engine, drain 2 qts, stop engine, fill 2 qts fresh ATF and you will be done. You will see fresh ATF at the cooler line.

Couple the cooler line back to the radiator.


Whilst servicing GM, Ford, etc with no drain bolt on pan I undo the return line at the transmission or the radiator and start the engine to drain about a gallon or abt 5 qts of ATF and shut off the engine.

now when the pan is removed I only get a small amount of ATF to handle in the pan whilst under the car, I do my filter change or work, button it back up fill it up with fresh ATF, do the cooler drain once again till I see fresh ATF being pumped out. For vertical split cases and no sump (Honda etc) I dont even bother to undo the drain - I do the cooler line drain and refill


however I still advise to check the torque converter for the drain, you will need to rotate the engine very very slowly to see the bolt, bumping the starter spins the engine very quickly for finding the bolt through the little 1 inch window in the transmission bellhousing.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)