Deere 244j wheel loader 4th function hydraulic oil leak

Hey everyone. My Deere 244j has an oil leak at the 4th function hydraulic coupler swivel joint. I want to replace the o-ring but can't find any specs as to the size. Called my dealership and they didn't know either. Deere wants $80 Canadian for a replacement but if I can fix it without buying theirs I would be much happier. Thanks

Deere 244j wheel loader 4th function hydraulic oil leak