I purchased a used fill station, NOS brand, ~2 years old. Now, I am just testing it with no nitrous bottles hooked up, I was just concerned about the verifying functionality of the pump. I connected an air line to it at ~125psi and opened both the air valve and the line valve. At this point, I expected the pump to start hammering... but it did nothing. I know that you're not supposed to run the pump dry, but I wanted to give it just a quick test to verify that the pump works so we can complete this transaction. Am I doing something wrong or the pump bad or what?

 

you must have the mother bottle hooked up to push the piston back up! the air pushes the piston down!!

 

That is what I figured, thanks for the heads up. :-)