I'm in pain...I followed your advice...have been to two autoparts stores and tried two brands of mini grease guns (Powerbuilt & OEM) and been unable to get the guns to operate (it doesn't help that nobody working in the stores knows how to operate them). I now have the OEM brand www.oem-tools.com mini gun (25703) with needle (25719) but after loading it with grease and pumping the trigger nothing comes out. Before I left the store, I asked them about attaching the needle to the coupler since no instructions are provided. He unscrewed the coupler end, removed a small spring, inserted the needle and put it back together again. Something tells me its blocked and there is some type of adapater that is supposed to go between the coupler/needle. Anybody have any experience with this? Thank you.