Grease Gun help

[Slime101]

Help me - i have a grease gun, its definatly got grease in it but i canna get any out!

This may sound simple, you know, squeeze the handle and out comes grease but it doesnt.

HELP!

EDIT: This one

 

[Slime101]

No canister - its a put in pot of grease and sucky up type. then tis full.

As far as i know its set up right but with no instructions i canna be sure!!!

No, its not new, used it before, return home, go to grease trailer bearings and nothing comes out.

 

[Slime101]

you see the small screw on the top near the lever unscrew it a couple of turns its the knurled one pump until grease comes out of the little hole at the side of the screw then tighten the screw , it sould then work

its got a air lock in the pump

Only just got this post....but i had managed to work out it was an airlock, and round the said screw

Thanks for your help anyway