134A low psi side valve insert replaceable ?

[Beastie]

Okay in an attempt to take a short cut I took the 85 300SD ( conv. 134A years ago) to a gas station and they were going to top up the a/c. After I drove down the road it got warmer in the cabin. I stopped and looked and there was
134 oil leaking from the plastic cap on the lo side quick disconnect. I carefully removed the cap and a small metal Pin rose up from the center and I realized the valve had failed. That said I am familiar with a std schrader valve and know the internals can be replaced. This newer valve has a plastic sleeve in it that looks like it has an internal head head design for unscrewing and installing a replacement. Is that true or do I need a whole new hose with the lo psi quick disconnect ? If it is replaceable it should be a .98 cent piece easily replaced.
Is my assumption correct ( yeah ! yeah ! I know when you assume something you make an Ass of U and Me)
Alan