I was reading this thread https://www.dieseltruckresource.com/...ocedure-28362/

where someone discussed purging all old fluid by opening up lines and draining into a container with engine in neutral.

I had a drain plug put into my pain years ago, and have done the filter/fluid myself before, but without purging all the fluid. Could I achieve the same purging by draining the fluid from the pan, and then turning the engine on briefly in neutral, or would that be too dangerous? How much fluid is up in the lines when you just drain the pans? And I forget what the fluid capacity is . It's been awhile and much overdue!

 

fluid and filter change is fine as long as the fluid ain't all burnt to ****.
8 quarts with stock pan

 

There may be a little more than a pint in the line, but you still wind up with a ton of oil in the torque converter that isn't going anywhere.

 

I am unsure if the stock converter has a drain plug on it or not as I have had my rebuilt trans and aftermarket tc in too long to remember. If it does simple enough to remove the inspection plate, bar the engine over to get access to the plug, pull it and drain it. IIRC my 47re draining the tc, draining the pan I need approx. 16 qts to fill it back up.

I don't do this as a normal thing but I seem to remember that one time I had to pull or loosen the valve body for some reason years ago and another quart or so drained out.

 

OE has no plug.

 

1. Drain the pan, change the filter, and refill the trans.
2. Disconnect the return line from the cooler to trans. and put a small hose on it and pinch it off, start the engine and release the hose into a gallon container. When the container is full, the torque convertor & cooler has been purged.
3. Refill trans to full mark, you're done