I mac be wrong, it happens...

But my understanding is the valve cannot rotate if the spring nut is held still... I find it nearly impossible to believe there is that much wear in the valve face though.

The valve may be destroyed...

Take pics, and use good lighting and watch the valve stem when turning the top nut. If it's not turning when the top nut is...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!