Snap-On R12 gauge set

[Dave in Texas]

Replaced gaskets/seals in depressor end of my hose set and decided to replace schrader valves in manifold set. One in center port, no problem. Low side port end has what looked to be a schrader valve. When I removed it, surprise. The visable part looks like the end of a valve, but the inside does not. Looks more like a destroyed end. No seal, just a long rod with spring around it. Missing the seal pieces/parts like the normal valve has. I put it back in, but it was loose to begin with, so I believe I found my leak. Holds ok with sealing cap but.....worries me.
The High side has only a blank Brass end port to hang/screw the hose to for storage.
Anyone know what the schrader valve-looking end piece is? Not sure if I should install a good schrader in or replace the Brass port-end with blank like the High side has?

Thanks

Dave

[Dave in Texas]

Bleeder valve for the low pressure hose.