Old thread response
Well I have to at least replace the back washer after today. I also could not find the washer in a parts diagram after I got home. This is the first time I've changed the fuel filter in my DK40HSE. The owners manual mentioned bleeding it but it wasn't clear to either loosen the bolt or take it all the way out. Curiosity got the best of me and I took it all the way out. Oh, I see and went to put it back together. What I didn't see was the rear washer has slipped out enough to just catch one edge of the fitting. I thought the bolt felt slow to tighten. Fuel running out when cranking it over told me something was askew. Taking it apart I then saw the back washer just catching the edge of the fitting. I got it back together and running but it's weeping fuel. Sadly it's over 100 miles away so another trip and now I wish I had taken the washer out to bring home with me.