With leaks around the delivery valves, I am installing the viton O rings (from Jim at fryerpower.com) on them and replacing all of the O rings at the same time. To echo others, thanks Jim for your packaging of them well identified on a piece of paper, instead of just placed in a baggy and we are on our own to figure it out!

Mercedes Benz designed the fuel return lines with the fabric wrapping so that when the line eventually cracks from age and heat, it will merely leak instead of breaking open with fuel spurting all over, and maybe leaving you out of fuel somewhere. The viton return lines do not have that wrapping, so when they eventually crack, fuel will spurt out.

It is not a problem to check those return lines weekly on the 601, 602, 603, and older diesels, but the 606 has a cover over the valve cover which blocks quick access to the return lines. So my only warning of a leak from a crack will be after the fact.

Any other 606 people have thoughts/concerns about this?

They don't just blow. Viton generally doesn't crack, what I have seen is they start leaking right at the barbs, and they don't just blow at once, they start leaking a little first. I wouldn't worry about a major blow out. I've had viton lines on my injector returns for over 2 years and they are still bone dry. Also I work for GreaseWorks.org I have seen a lot of rigs come in with viton in various states of life, and I've never seen it crack.

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Doubt they will burst; more likely will begin weeping when the fuel line ages to point of failure no different than the MB return lines. When tht happens you'll see or smell the fuel.

Mine are original on the 99 to the best of my knowledge and no leaks to date.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

I recenlty installed VITON on the return lines. Got tired of the leaks with the OE part.

Thanks for that feedback.

How about a source for viton hose for the main fuel lines (in the engine compartment that connect between the metal lines to/from the tank and from/to the fuel pump/fuel filter)?

Dave

The lines to and from IP/Fuel filter housing, etc. don't degrade to my knowledge; the orings sealing each end of those lines is another matter.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Fuel lines to the injection pump: From what I have read on the Diesel Giant site he said that when using SVO/WVO it is the old hoses that leak. If you replace them with regular new hose they will last almost as long as they did when diesel was used. No doubt that viton is a better long term choice.
I also noticed when I was looking on the GoodYear Rubber hose site that alot of there regular hose said it could be used with biodiesel (on the spec. sheets).

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84 300D, 82 Volvo 244Gl Diesel

Unfortunately, you can't by Viton lines from this wonderful site but you can get them at McMaster-Carr. Double check your size and order a few feet extra.

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1987 300SDL-268k mi

This is my question as well as mine are starting to crack and one of these days I want to replace them with good lines, either Viton or OEM if they will last....

The OEM lines have a series of bends in them so that makes it more interesting...

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#dieselFLEET
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'97 E300
'99 E300