I smelled diesel fuel inside the van tonight and used my flashlight to investigate the leak. The cover around the blue spring is damp.

Before I remove every again to gain access to the filter housing to fix the leak can anyone advise me what I am may encounter. Seems like a good time to do the blue spring upgrade. Can I access the egr valve to inspect and clean?

What are the possible areas to check for the leak?

Sometimes finding little problems leads to finding big problems. When my FICM went out I discovered the battery terminal clamp was broke.

 

I would be leaking too with that many miles on me lol. It's a no brainer to do the blue spring, and you can do that for sure.....dieseltechron has a good vid on that.
mchan might have a better idea what you should look for on a van.
Here is the drawing for an '04 E series just for the sake of an exploded view.

 

I want to do the blue spring upgrade. No better time. The miles on this van is amazing. I have put on 2000 miles and total cost including price of van is $1 per mile. I thought I was in the clear for a while until the fuel leak. It smelled like diesel when I bought it. Took 3 months to find the leak.

There are some damp lines but cannot see in the dark. It's not dripping.

 

Thanks for the exploded view drawing. Maybe Ed @ficmrepair can sell me the o rings and blue spring kit.