Appreciate the remarks and suggestions.

As I typed the original note, I couldn't for the life of me figure out why the stupid extractor continued to gush oil after I released the air pressure.

Later it dawned on me - the inlet for the hose is attached to a tube on the inside of the container that goes all the way to the bottom of the canister. The air I was injecting was going in under the oil - bubbling up to the top and then pressing down on the oil. No way for it to escape back up the hose...

My modification to allow me to use air to force the oil out of the canister involves a male quick-connect fitting on the top of the canister where I can connect the air hose. I cap the fitting with a rubber plug for extracting oil. If I'd have simply put my finger over the end of the hose and connected the air at the added insertion point, all of this mess would have been avoided.

Haste makes waste...

In hind-sight, I guess I shouldn't have changed the oil hot. The canister doesn't deform when the oil isn't hot. The "max fill" line is at about 8+ quarts, and I extracted a maximum of 7 quarts, since that's my normal refill amount.

However, extracting 20W50 oil cold is a lot more time-consuming than 20W50 hot. Plus I hear that Larry Bible "change it often, change it hot" quote in my head.

Oh well - live and learn.