Which Yanmar machine do you have?Looks like a ISO 7241 Series A fitting:
http://ph.parker.com/us/17559/en/qu...41-series-a-6600-series-6600-series-nipples-1
I suggest visiting a shop that specializes in hydraulic hoses. My local shop was able to match up my Yanmar's loader quick-connects so I could plumb in a snow plow. The loader quick-connects are different from the rear-remote quick-connects.
Which Yanmar machine do you have?