It turns out, what I was calling the hydraulic tank was wrong. The tank in question is the transmission tank or (the tank under the batteries at the very rear of the d21E-6 dozer. ) Why are there 3 drain plugs but only one has oil in it? Are the other two meant to be for a tool access to the dry clutch area? Thanks, Larry.
I have a D-21 P6 Middle tank is gear oil outside two are dry, bottom threaded hole is a drain