Tools for Valve Spring Replacement Needed

Another approach is to look around for a "deal" on a compression tester, which you ought'a have, anyway, or a leak down tester, which you can make.

If you get "the right" type of compression tester, it will have a quick coupler same as air hoses use, known as Industrial Interchange. Some of these gauges use oddball connectors

All you need to do is take a tire tool and yank the tire valve out of the cylinder end of the hose, and use that for your air fitting.