Those valves seem to have a design problem. Mine were "reconditioned" under the warranty, and they still leaked. Then they replaced them under the same warranty. Today they still leak, and I have learned to live with it.
Below is a picture of the valve. I doubt that you have one on you Quincy since mine was a "special offer" and I had to install it myself. I don't remember if the driver handed it to me along with the instructions on how to mount it or if he told me how to do it and what to buy. That is darn near 40 years ago, and I am not even certain about that timeline. I guess it was too much for them to install it before the compressor was delivered. I installed the brass valve and the copper line. I will have to get a picture of how the copper line connects to the painted blue line. There might be something in the manuals about this, however, I am not even certain where they are.
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