JD 310 fuel return line leaking at injector- oring?

The number 1 injector on my backhoe is leaking out the return line fitting on the injector. I loosened it and then tightened it and that helped but its not dry. Is there an o-ring in there? My JD dealer wants to sell me a new line, but I'm thinking I might just need an o-ring. Anyone know what size it is?



Thanks

Dave

JD 310 fuel return line leaking at injector- oring?