OK folks any tips? I'm changing for 10-40 oil to a 20-50syn blend. How can i best get the most of my old oil out of the hydro system. I know to pull the filter & Disconnect the tank return line to drain the tank, but what about the pumps & motors...what do i need to do to get the old oil out of them? Or should i not need to worry about it & change what i can?