oil purge without air pressure?

It was probably easier to just say "Do It Anyway" than write an "If ... Then" instruction.  Or even more likely, it is just an Oops!

If the level of the oil in the tank is above the Oil Pump Input fitting (Most are!) then gravity can replace Air Pressure.
Loosen the Oil IN Fitting at the Oil Pump. This will allow the air to escape as the Oil drains into and fills the Hose.
Once Oil starts to flow from the end of the hose, the hose is filled with oil.
Tighten the Fitting and then proceed to hand crank until you register Oil Pressure.

Thanks Bill.  That all makes sense of course.  The oil level on one of mine is above the inlet, but on the test stand engine the level is below.  I have the fittings, and will likely just use the air pressure as recommended, but I was curious about the no-air-pressure procedure.

Rusty

I just did this yesterday. I didn’t use air pressure but I cranked that prop more times than I could count lol.  

I checked all of the lifters and all solid. So it can be done without air.