JohnHere,
Thanks much for the comprehensive advice. I have already replace all most O-rings, but I will replace all others. What type of "sniffer" can, I as an armature, get myself to do this type of checks....or if too expensive, I would take it to a "professional".

You've got GOOD caps on the service valves, correct? Virtually all schraeder valves leak some. Cusser, I have what the Vintage Air folks sent me. And they are good and "hand tight". Is there a "leak detector" that works? I was thinking my first step would be to but in new schrad...

I have a car that I put a vintage air system in recently. It took me about 3 months to finally get the system charged because I was working on other parts of the car, as this is a restoration and modification to this car. So, I finally went to get it filled up and within a week the freon leaked out....