I removed my fuel filter assembly when I replaced my return line. After putting everything back together I noticed I had a fuel leak on the front banjo fitting on top of the fuel filter assembly. I must have lost the seal at some point but I couldnt find it so I used a rubber o-ring. It only lasted about a week and fell off. What can I use to seal that fitting? Do I have to go to the dealer? Thanks.

 

It takes a copper washer. Most any shop that deals with diesels can get you one.