No Fuel in Metal Lines

[bpeters2]

My 85 300td won't start after sitting up on blocks for a few days. The lift pump is just pumping air. One of the lines was a little wet so I suspected leakage...when I cut out a section of line there was NO diesel at all in the line. I'm not sure what line it was (return or supply) but it was the "inside" line of the two. I'm not familiar with how the fuel lines go into the tank, but does this indicate that I have a clogged fuel screen. It seems that if the fuel line come out of the bottom of the tank, then I should have had fuel pouring out of the line onto my face when I cut the line, regardless of which line it was. I thought about low fuel level so I added 5 gallons, and it was still pumping air. Any ideas, or things I may have overlooked. Sorry for posting this twice, but I had a typo in the previous thread's title which I worry was limiting the number of people reading it. Thanks

[Diesel911]

My first thought would be that you fuel tank filter/stariner is plugged up. Try loosening the rubber hoses back there by the fuel tank itself and see if you get any fuel. Bring a container to catch the fuel if any comes out and wear your old clothing. Be ready to shove the fuel hose back on if a lot of fuel comes out.

[bpeters2]

Thanks for the advice. It seems to me that the lines must be plugged. One if thge metal lines was empty and based on the fact that the return and supply lines come directly out of the bottom of the tank (I assume this is fact from pictures) then if there was a leak then I would be seeing diesel fuel leak out when I put 5 gallons in the tank. Now I just need to figure out how to fix the clogged screen.

[bpeters2]

Anyone know the size of the O-ring for the fuel screen (on tank). Specifically, I'm interested in the size that would be needed for a wagon-style fuel screen. Any chance I could get the proper size O-ring at a Napa or Home Depot or something? Thanks

[bpeters2]

One more question..How do I determine which line is the supply vs return line when looking at where the lines connect to the tank (without tracking the lines all the way to the engine bay)? Is one closer to the Fuel Screen (or other notable "landmark") than the other? I assume the supply line would be closest to the screen.
Thanks

[bob_98sr5]

bpeters,

i believe we are going along the same path member jadavis ( jim) of fryerpower.com sells o-rings and other essential viton hoses including injectors, IP rings, etc on his website. jim's a great guy to deal with and his product prices (except for the shipping seems to be waaay too high--honest feedback, jim) are fair. he's got kits specifically for diesels like yours.

look on dieselgiant.com's site. there's a mercedes maintenance page with a pictorial on changing fuel lines that will answer your questions

...and GO BLUE