I am trying to determine the correct I.D. (inside diameter) of the fuel hose that is used between the fuel injectors and the filter return. The fuel hose will be used in a 1987 300TDT (W124 chassis). I have done a search of the forums and found the sizes of 1/8" ID, 3.0 mm ID, 3.2 mm ID, and 2.5 mm ID mentioned. The WorldPAC catalog calls out in the description "Fuel Hose, looping return line, Leak line to injector" but there is no diameter listed, and the hose is actually unavailable right now.

Also, does anyone know if a bio-diesel compatible version of the fuel hose is available i.e. a viton hose with the braided covering?

Thanks in advance.

-Steve

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1987 300TDT smoke silver w/ burgundy leather interior
2000 VW Passat wagon indigo blue w/ beige leather interior
1985 Mustang SVO
1970 Chevrolet K10 fleetside, shortbed

1/8" is what we use in the shop. I've never seen cloth braided viton. You can get an injector return line kit from www.greaseworks.org that is viton.

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Here is the OEM part and size.
MB# 605 078 05 81
Diesel Return Hose 3.2 X 1.9 mm
For Diesel Injectors
(Sold by the Meter)


Custom fitted Viton® hose kits for a variety of vehicles
http://www.greaseworks.org/index.php?module=pncommerce&func=categoryview&CategoryID=11

Thanks for the info posted so far. I did some checking, and the EPC lists the MB part number 615 476 03 26 for the fuel hose used between the injectors on a 1987 300TDT. This matches the number on the bag from World PAC. This is different than the other 605 number listed by whunter earlier in this thread.

I typed that MB number into the search function for WorldPAC and it states that the product is currently unavailable as I mentioned earlier.

Background: When I originally ordered some fuel hose from World PAC, it came in a bag marked with the part number 615 476 03 26. The SKU number is listed as E5000-103594 on the invoice. The description is "Fuel Hose, looping return line, Leak line to injector" in the parts catalog. I ran out of the hose I got from World PAC, so that is why I am trying to order more, but the system states it is unavailable. There is bulk fuel hose listed, but only by the diameters of the hose. I did manage to find some 3.2 mm hose locally, but it appears to be slightly larger in diameter than the hose 615 476 03 26.

Any more thoughts or ideas? Thanks again for the info posted so far.

-Steve

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1987 300TDT smoke silver w/ burgundy leather interior
2000 VW Passat wagon indigo blue w/ beige leather interior
1985 Mustang SVO
1970 Chevrolet K10 fleetside, shortbed

Part number 615 476 03 26 has been superseded by MB# 605 078 05 81
Diesel Return Hose 3.2 X 1.9 mm
For Diesel Injectors
(Sold by the Meter)

Thanks again whunter for the quick response.

So the 615 476 03 26 has been superseded by MB# 605 078 05 81? My EPC is a few years older so it probably has been superseded in the last few years.

The 605 078 05 81 is used on the 1999 E300D it appears. The WorldPAC catalog shows a part number E5000-268180 and an ID of 3mm an OD of 7mm for the fuel hose. (As opposed to an ID of 3.2mm and a wall thickness of 1.9mm.) It is sold in a one meter length for roughly $40. I wonder why there is such a steep increase in price. The dealership charges roughly $13 a meter for the 615 476 03 26 fuel hose. The new part number is about 3 times more. Is the new part number bio-diesel resistant or something? Is it made out of viton? It seems to have a white-gray braid color as opposed to black-gray color on the original hose.

Thanks,

-Steve

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1987 300TDT smoke silver w/ burgundy leather interior
2000 VW Passat wagon indigo blue w/ beige leather interior
1985 Mustang SVO
1970 Chevrolet K10 fleetside, shortbed

Here's an update.

I checked on the Febi website, and it lists the ID of both the 605 078 05 81 and 615 476 03 26 fuel hoses as being 3mm, and the OD as 7mm. Here's the link:

http://212.110.107.100/febi/webartikel4.api?p_proc=verwend_artbez&p_session=794785&p_artbez_id=362


I think I'm going to send Febi an e-mail and ask them if the 605 078 05 81 fuel hose is bio-diesel resistant.

Thanks,

-Steve

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1987 300TDT smoke silver w/ burgundy leather interior
2000 VW Passat wagon indigo blue w/ beige leather interior
1985 Mustang SVO
1970 Chevrolet K10 fleetside, shortbed

I have been using 1/8" i.d. blue transparent polyurathane hose from McMaster for my return lines for years. Less than a dollar a foot and they hold up to B100 pretty well.

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Ron Schroeder
'85 300 Turbo Diesel 2 tank WVO
'83 300 Turbo Diesel 2 tank WVO
Some former WVO vehicles since ~1980:
'83 Mercedes 240D
'80 Audi 4000D
'83 ISUZU Pup
'70 SAAB 99 with Kubota diesel
'76 Honda Civic with Kubota diesel
'86 Golf
Several diesel generators
All with 2 tank WVO conversion
LI NY

I had to salvage a return line off another benz I have in the yard with a bad tranny. By removing this return line that travels to the fuel filter will it in any way siphon or keep draining until I either install another hose or the tank empties?

Ditto on 1/8" ID clear polyurethane hose.

This hose is advertised as fuel line safe for small engines, and works just fine for anything supplying the fire to my 300D. This hose is cheap easy for me to get down the street. I can afford cutting it off each time I need to R&R an injector or what-not. Stays relatively elastic for years. It does turn brown with fuel flowing through it, but no matter. Can easily handle the heat too. And it is super abrasion resistant, often used as a slip cover over things ou don't wearing through from rubbing on something. In fact, it's hard to cut off a piece of this hose without a real sharp blade or tool with scissor action.

Don't go buying just any clear hose from your hardware store, it will likely be vinyl.

You must be sure it is polyurethane nothing else.

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Cheers!
Scott McPhee

1987 300D

Where can this line be purchased? When installed and the engine running should there be any air bubbles in the return line or should it be solid fuel going through it?

The polyurethane hose I get at this Canadian supplier:
Greenline Hose

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Cheers!
Scott McPhee

1987 300D

What are you all using for an end plug on the 1/8" poly tubing? I screwed a small bolt in there. Super tight yet still leaks a little.

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Studio B Fine Art Prints

I'm using fuel-safe 1/8" black hose from the corner parts store. I don't expect any issues. It pushes on tightly and I can't imagine it would leak.

For the end plug I just salvaged the one from the stock line. I had to cut the old line with a razor knife to get the plug out as it fits REALLY tightly.

Dan