Anyone had an experience with air operated grease guns? I've been
using a hand operated one for many years, and a few weeks ago decided
to try out the air one. Makes sense-you have less work to do and let
the air do it for you. So I tried a "cheap" one at Harbor Freight.
Knowing fully there's a wide range from pretty good stuff to absolute
crap at that store, and you have to know what you're getting, or
it'll turn out to be those "use-it once" tool and it either
breaks or is too flimsy to spend time on it. Well, the gun might have
been in the latter category. I played around with it for a couple of
hours, trying to get it to work. After taking it apart and analyzing
how it worked, I concluded the rubber "plunger" did not want to
slide inside the cardboard section of the tube of grease. So I cleaned
it up and returned the unit.

Just recently I decided to try a more "expensive" one, so picked up
Sear's best, with the "continuous flow" feature. (Yea, right).
Anyway, same deal here, the plunger just would not go inside the
cartridge tube to push the grease into the air pumper part. Yet, on my
hand operated one it does. Weird. So I return that one as well. I read
both directions on both units on priming, etc, but still no good.

So am I missing something, or is there a trick?