Is it safe to idle, for a minute, the engine and transmission in neutral when the transmission pan is empty? The goal would be to pump the remaining fluid in the converter and in other places into the empty pan.

 

I would not do that the pump will have no lubrication when you so that.

 

do not do that if you really want to try a hillbilly flush change the fluid and filter then before starting remove the return cooler line and overfill the tranny. Then start and measure how much comes out in a bucket of something shutting the truck off before it runs dry. Filling it will probably be a pain after this and you likely won't gain much over regular trans services, this includes band adjustments.

 

Look on the torque converter...a lot of the time there is a small drain plug.

 

This procedure works. After overfilling the trans, I idled it in neutral while the wife poured more fluid into the dipstick. It doesn't even take half a minute for the pump to push 2 gals of old fluid from the return cooler line. My fluid is so clear bright red now!!!

I did my band adjustments 4000 miles ago.