Can you post a picture? Are you sure its a male thread and not a short nipple?
I believe this current problem (bad oil leak at one valve-coupler interface) is a repeat performance of a problem I had years ago... a bad o-ring. I am half going by memory/external inspection and half by the Mahindra/KMW parts diagram which shows elimination of the valve-to-coupler adapter on the last iteration of my ML112 loader. The value port size is SAE #6. The machine is not here at the moment so I can't snap a photo.What size is the male thread?
The thing is that I'd like a couple spare couplers as the machine is getting old and the couplers are starting to show signs of wear. I think that all will be well again for now once I change out the o-ring under the coupler and replace the internal o-ring and Teflon back-up ring too... but I won't be certain about that until tomorrow or Monday.