[hj60]

Originally Posted by archie

I think I have an AC leak and noticed flourescent green dye on my Low valve and cover when I opened it. I looked with a black light all over the place for other leaks but with no luck in finding the leak. I think this valve is the source of my leak and wonder how do I repair it. Any suggestion? Thanks in advance.

You can buy just the valve core at most auto parts stores.
I keep a couple in my toolbox. Sometimes they just come loose. They're like a large tire valve core. A parts store should have the tool for it, too.
On our domestic trucks, we automatically replace the high and low service ports/valves if it's been more than a year since the AC was worked on.
I got tired of charging a system up, having it freeze out the driver and pass all leak tests, only to come back a week later not working.

Had one S-10 where even after I replaced the valves, it still leaked down in a week or so. After nearly pulling my hair out and putting my tools on Ebay, my boss discovered that the cap was depressing the valve just enough to allow a slow leak. We laughed for an hour straight at how many hours we had both put into that thing.