Were you able to fill the other two guns previously with the same hand pump? Do you hear the hissing sound of air when you are on the down stroke, as if you are not getting a good seal, either from your gun or connection? What type fitting do you have, QC or probe?
I’ve heard ppl having trouble filling from empty. I got the disco/hand pump combo. Had a back valve check seal. Had to take it apart and clean it. Pump filled up from empty just fine?
Thanks! I was sweating all day pumping,getting no pressure, changing o-rings, about to have heart attack, I'm 56, trying to figure what was wrong. Disassembled gun maybe 4 times...now I know!