Power Steering not working

A working pump will cirlculate the air out pretty quickly, and especially if you turn the wheel lock to lock a couple of times.
It's actually WAY to comon that the large O ring leaks or the pump does not work at all on remans.
You could put a pressure guage on the high side (Steel line side) and see if you get good pressure, but it might be more trouble than it's worth.

One good clue that the pump is working is that when you first run it, you should hear a fair amount of squealing and see foam till the air gets circulated out.
If it never squealed, foamed or groaned then it doesn't work. (The rule I go by)