Campbell Hausfeld RP120001AV small tire inflator - no pressure

Hey Gents,
 
I have this model tire inflator, used, and it seems to work but no pressure to tire/football. Searching the web to learn to diagnose, heavy duty pump sites list possibly something blocking the hose or a leak, but both seem unlikely.
 
Otherwise have seen a Part #: MC120001AV - Stator Assembly listed but no longer produced. Know what a stator is but the motor appears to push the pump arm (which manual says is permanently lubricated).
 
Would anyone have any advice re: how to diagnose. I'm trying to fix it myself vs. spend $25 on a new one. Unit looks to be in good shape. Confounding. Is there a seal or part the arm moves that could be worn that I can easily replace?
 
 
Thanks,
 
Mac