R134a conversion port "Schrader" valve doesn't come out ???

[YY1]

So, last week I drove my car to work and the AC quit blowing cold on the way home.
Yesterday I started poking around and as soon as I took off the cap from the port on the back of the compressor, it hissed out 134.
OK, so far easy enough. But when I tried to tighten the valve, it didn't move and was difficult to get a tool on. I tried all three I have.
Upon closer inspection, it seems like the valve is permanent and not removeable.
???
That sucks, because now I'll have to waste whatever 134 is still in there and pump it down for a full charge, instead of just tightening or replacing that valve.
I do have a new conversion valve, and it looks like it doesn't have a removeable "Schrader" valve either.
Pics of conversion valve online seem to show standard removeable valves.
Are mine just cheap? Should I get better ones?

NOT the ones I have.

 

[YY1]

Gee, nobody has had this issue?

Advance had a kit for $16, but couldn't guarantee the valve was replaceable and wouldn't open the package.
O'reily's had three different kits, and the one without the oddball gm part was only $8!
Took that chance and the valve IS replaceable.
For some reason, though the new adapter is twice as long as the old one, or as it needs to be.
That's gonna put it real close to the top radiator hose. Why would they do that?
Also learned there's another valve in the original connector that gets pushed by the schrader in the adapter.
That likely means the OEM connector valave is also leaking.
Drat.
Today, though it means I didn't lose any gas removing the adapter.
I think I'm gonna go ahead and put the new adapter on and let that valve contain the refrigerant for now.
Next time it happens, I'll vacuum it down, and replace the OEM connector valve.