Watts TWS-8 Wall Hydrant Repair

[Del Mar Apartments]

I have a Watts TWS-8 wall hydrant that has reduced water flow. Initially, there wasn't enough pressure coming out to activate the sprinklers. So I tried to disassemble it for a good cleanout, however, I could not remove the head body or plunger assembly. It turned about 1/4 of the way and then came to a hard stop. Is there any special technique to take this apart and it clean or is it permanently sealed? I poured cleaning vinegar into the valve body and let sit for 45 minutes. This helped the flow and activate the smaller sprinkler heads, but it still needs to be opened up for a thorough cleaning.

 

[Geofd]

We have similar silcocks, I think smith, the sell repair kits for most (smith) models mine comes with a socket.
You have to remove the shaft to get to the stem that's what the socket is for (smith)
Stem is threaded into the silcock body, I usually put a little putty in the socket so the stem stays in, now you can inspect the inner workings and flush without restriction