I built a cheap bottle jack one that ended up leaking badly enough I used it enough for 8 injectors, tried to fix it better then gave up on it. Then I spent the $50 for an Ebay special Chinese porta-power replacement(pump and hose only). Add the hydraulic fittings from mcmaster-carr and I think it's around $85 if you already have the gauge. WAY BETTER IN EVERY WAY. I will say that it still leaks down a little so the best thing is to get a check valve of sorts between the outlet of the pump and the injector. This is how the porta power units do it anyway if I'm not mistaken. That's great news about 7 of 8! Hopefully it is just some sort of contaminant on the last one and they run right in no time.