viton fuel system replacements? - PeachParts Mercedes-Benz Forum

patbob · #1 11-22-2006, 12:55 PM

I'm experiencing a fuel leak from someplace after filling my 1983 300D turbo's tank yesterday. I'll be chasing down where the leak is over the long weekend, but since I run biodiesel in the car, I'd like to replace whatever I find leaking with viton equivalants (I've already done the fuel hoses, so I don't think its them).

Can anyone point me to a site that either knows the viton equivalants of all the seals, hoses, etc. in the fuel system, or the set of sites I'll need to make the cross reference myself?

The docs I have talk about replacing the seals, but don't give the MB part number or specs on the O-ring needed. The electronic parts catalogs I checked allowed me to buy the parts, but didn't sell viton equivalants and didn't give me enough info to get them myself.

P.S> why isn't there a "smiley" for leaks?

vstech · #2 11-22-2006, 01:07 PM

tons of hits, but the third or so was this...
http://www.peachparts.com/shopforum/showthread.php?t=170949&highlight=viton

TheDon · #3 11-22-2006, 01:09 PM

just put regular mercedes fuel line.. it will last just as long and per the FSM is supposed to be changed ever 2-3 years...

Jadavis · #4 11-22-2006, 01:13 PM

Which seals are you looking for. I do quite a bit of work in supply chain management. As a side job I got really good at identifying o-ring sizes. If you can tell me which seal, I will see if I have it in my box of items I have bought from Phil over the last year. Then I will figure out the correct size for it.

I've already done this with the fuel tank screen and the two o-rings on the spin on fuel filter. They are for sale on my website, along with the injector return hoses.

http://www.fryerpower.com/store/page11.html

-Jim

Old300D · #5 11-22-2006, 01:58 PM

I've not seen any issue with seals in two years of running B100. Old hoses, yes, and new OEM seems to hold up as well. If you want to replace fuel hose, use 5/16" ID thick wall hard Viton from McMaster.com. Two feet is enough to do the fuel tank feed and the length from the hard line to the prefilter and between the prefilter and the lift pump. And of course the 1/8" ID for the injector returns, again two feet is enough.

patbob · #6 11-22-2006, 04:50 PM

Quote:

Originally Posted by Jadavis

Which seals are you looking for. I do quite a bit of work in supply chain management. As a side job I got really good at identifying o-ring sizes. If you can tell me which seal, I will see if I have it in my box of items I have bought from Phil over the last year. Then I will figure out the correct size for it.

I've already done this with the fuel tank screen and the two o-rings on the spin on fuel filter. They are for sale on my website, along with the injector return hoses.

http://www.fryerpower.com/store/page11.html

-Jim

Thanks.. I may take you up on that. I already ordered the tank strainer and fuel filter ones you offer (Aloha)

.

I don't know where the leak is from yet (that's going to be the fun part), but I know the leak isn't continuous while sitting or at idle, or even when I rev the engine.. only under load or when turning. It's a gusher though.. leaves a continuous dribble of diesel behind, so it shouldn't be too hard to find.

d.delano · #7 11-22-2006, 05:05 PM

I really don't think you need Viton anything. You just need to replace your fuel hoses because they're +- 20 years old. Biodiesel and the new ULSD simply exploit the microcracks and age-based flaws already present in your old lines. Since new lines aren't compromised, you have no worries there whether they're Viton or other.
I have fuel leaks since the switch to ULSD. Am I going to pay a premium for replacement lines made from Viton? Nope. Not necessary. Will I lose sleep because I did not use Viton? Nope.

For those of you that think Viton is now absolutely necessary, where you gonna find a Viton cigar hose?

Old300D · #8 11-22-2006, 05:24 PM

Quote:

Originally Posted by d.delano

I really don't think you need Viton anything. You just need to replace your fuel hoses because they're +- 20 years old. Biodiesel and the new ULSD simply exploit the microcracks and age-based flaws already present in your old lines. Since new lines aren't compromised, you have no worries there whether they're Viton or other.
I have fuel leaks since the switch to ULSD. Am I going to pay a premium for replacement lines made from Viton? Nope. Not necessary. Will I lose sleep because I did not use Viton? Nope.

For those of you that think Viton is now absolutely necessary, where you gonna find a Viton cigar hose?

A new OEM cigar hose works, but I'm getting an inordinate amount of fiber being flushed from it into my prefilter.

d.delano · #9 11-22-2006, 05:32 PM

Quote:

Originally Posted by Old300D

A new OEM cigar hose works, but I'm getting an inordinate amount of fiber being flushed from it into my prefilter.

Can you take a quick photo of that. I want to see. The fiber reinforcement is in the middle of a hose that is about 1/4" in wall thickness give or take.

vstech · #10 11-22-2006, 06:35 PM

Quote:

Originally Posted by Old300D

A new OEM cigar hose works, but I'm getting an inordinate amount of fiber being flushed from it into my prefilter.

exactly how do you know the fiber is coming from the cigar hose?
John

patbob · #11 11-22-2006, 07:46 PM

Quote:

Originally Posted by d.delano

I really don't think you need Viton anything. You just need to replace your fuel hoses because they're +- 20 years old. Biodiesel and the new ULSD simply exploit the microcracks and age-based flaws already present in your old lines. Since new lines aren't compromised, you have no worries there whether they're Viton or other.
I have fuel leaks since the switch to ULSD. Am I going to pay a premium for replacement lines made from Viton? Nope. Not necessary. Will I lose sleep because I did not use Viton? Nope.

For those of you that think Viton is now absolutely necessary, where you gonna find a Viton cigar hose?

You are right, Viton isn't necessary. However, since I run bioD in the car, and that has been known to degrade the 20 year old rubber, I might as well replace with Viton when I replace. If I can. And only because its just a few dollars more to do so. And a lot cheaper than having to do it a second time in the next 10 years. And because I'm willing to risk that there isn't somethign out there that'll preferentially dissolve the viton lines.

Heck, I'm not even sure my problem is hose/seal related.. it may just be bonheadedness, like a fuel return line getting disconnected and not reconnected. Problem did start after the mechanic had it a week ago. Yeah, that's the ticket. Anyone know where to get a replacement mechanic made out of viton?

d.delano · #12 11-22-2006, 10:50 PM

I agree then, go for it.
I'm just poo-pooing because I got enough OEM fuel line for three cars already

dieseldiehard · #13 11-23-2006, 12:08 AM

Quote:

Originally Posted by TheDon

just put regular mercedes fuel line.. it will last just as long and per the FSM is supposed to be changed ever 2-3 years...

the fact it is supposed to be changed every so many years tells me MB discovered it deteriorates after that time. In my experience it can deteriorate before then, I had a leak in a return line on a long trip that made the car stink of diesel and since then I have started using Viton (1/8 in hard from McMaster Carr) on the 603 engines. Even without running Bio diesel, Viton is the best rubber available for longevity. I don't mind the extra cost for return lines but wouldn't recommend using Viton on larger hoses unless you are using B100 and can obtain the right dimensional Viton hoses because if you crimp Viton on a tight bend or something it tends to break, it seems much easier to damage than OE material (Buna is really tough stuff!.
O rings in Viton is a great idea. If I didn't have a few dozen MB O-rings I'd buy some.

dsl4evr · #14 11-23-2006, 12:15 AM

lists Viton hoses for MBZ vehicles using biodiesel and/or WVO.

aersloat · #15 11-23-2006, 02:21 AM

There is a co-op/shop in Corvallis that sells pre-cut viton hose kits as well as bulk hose for the lazy... like me. They have some good info on their site as well if you are running biodiesel or veggie.