Not being familiar with the Astro extractor, what is the extraction tube made out of? If it is plastic, do NOT try to suck HOT oil...it will just collapse on itself and you won't get much oil. Let the engine cool down a bit and try to suck warm oil, not hot.
I think that you are at the bottom of the pan. If you weren't all the way down, you would hear the tube sucking air.
I think your oil is just too hot.