MB 7mm fuel line part number? - PeachParts Mercedes-Benz Forum

JHZR2 · #1 07-27-2019, 11:43 PM

Yes, looking for the 7mm ID MB official rubber hose (with the star printed on it) part number. This is the stuff that goes from the hard line to the inline filter, to the fuel pump.

Tried looking through some of the free online EPCs without much luck. It must be just a build shop item, but not sure how to find those parts.

Thanks!

tangofox007 · #2 07-28-2019, 08:46 AM

If you can overcome the need for the star, 5/16" fuel hose works fine.

Don't know if it's true, but I heard that genuine MB fuel hose is only necessary when using genuine MB diesel fuel.

Diesel911 · #3 07-28-2019, 11:15 AM

If the Mercedes dealer dose not use the 5/16" hose it is likely they simply have a large roll of the 7mm Hose (I thought it was 7.5mm) that they cut what they need from.

I have has zero issues with the 5/16" Hose. Perhaps you could use the 5/16" house until you find a source of the Hose you want.

JHZR2 · #4 07-28-2019, 03:01 PM

I’m running 5/16” hose. I have a slight idle shake that I think my might be attributable to this. 5/16 is 7.9mm vs 7.0 that’s spec...

Not set on mb for the star, but rather because it’s right and seems tough to find quality rubber everywhere in odd sizes.

83w126 · #5 07-28-2019, 04:09 PM

The auto parts website named after a state starting with "A" sells metric fuel line in 7mm and other sizes. If you go to the dealer they would usually make you order a whole roll. I wouldn't use 5/16 line to replace metric line either, its usually poor quality and doesn't fit right.

JHZR2 · #6 07-28-2019, 07:02 PM

I’ve bought it by the meter from the dealer before. Just never logged the part #.

Diesel911 · #7 07-28-2019, 08:02 PM

Quote:

Originally Posted by 83w126

The auto parts website named after a state starting with "A" sells metric fuel line in 7mm and other sizes. If you go to the dealer they would usually make you order a whole roll. I wouldn't use 5/16 line to replace metric line either, its usually poor quality and doesn't fit right.

I have not bought any lately but out here the chain auto parts stores sell Goodyear or Gates fuel hose.

People in the past have used the 5/16" regular fuel hose (it is rated for diesel fuel
(SAE 30R7 is the Regular Fuel Hose)

the 5/16" Fuel Injection Hose (the Goodyear hose has a blue Viton lining and the Gates version has a brown Viton lining) or Viton hose of which I have no experience with.
(Fuel Injection Hose SAE J30R9 or 30R90 SAE 30R9--)

There is only 2 issues that I think could cause the 5/16" line not to work or a combination. One would be he is using the filter with the metal nipples and from what I have seen they have a skinnier OD on the. The other would be if the Clamp being used will not tighten down on 5/16"

The Mercedes fuel line clamps are nice but they don't have as much range as some other clamps do.

tangofox007 · #8 07-28-2019, 10:32 PM

Quote:

Originally Posted by 83w126

I wouldn't use 5/16 line to replace metric line either, its usually poor quality and doesn't fit right.

Since when is diameter an indication of quality?

I have been using 5/16" fuel hose on a W123 for almost three decades without the slightest hint of a problem.

JHZR2 · #9 07-28-2019, 11:05 PM

Quote:

Originally Posted by Diesel911

I have not bought any lately but out here the chain auto parts stores sell Goodyear or Gates fuel hose.

People in the past have used the 5/16" regular fuel hose (it is rated for diesel fuel
(SAE 30R7 is the Regular Fuel Hose)

the 5/16" Fuel Injection Hose (the Goodyear hose has a blue Viton lining and the Gates version has a brown Viton lining) or Viton hose of which I have no experience with.
(Fuel Injection Hose SAE J30R9 or 30R90 SAE 30R9--)

There is only 2 issues that I think could cause the 5/16" line not to work or a combination. One would be he is using the filter with the metal nipples and from what I have seen they have a skinnier OD on the. The other would be if the Clamp being used will not tighten down on 5/16"

The Mercedes fuel line clamps are nice but they don't have as much range as some other clamps do.

I’m running NAPA 30R9 hose. Curious what stores sell Goodyear since I think it’s all Continental now.

I do think this car is running a filter with the metal inserts... that could be the situation.

Interestingly, the prefilter has next to no air bubble in it...

JHZR2 · #10 07-29-2019, 06:42 AM

Quote:

Originally Posted by tangofox007

If you can overcome the need for the star, 5/16" fuel hose works fine.

Don't know if it's true, but I heard that genuine MB fuel hose is only necessary when using genuine MB diesel fuel.

Don’t particularly care about a star, I do care about a nearly 1mm ID difference.

Cloth braided 7mm hose is readily available but not a long-lasting choice. It seeps after some years even with very low miles. The proper dealer hose has worked for me for long periods. That’s reason enough to seek it out to order from a discounter like Pelican, if I had the PN.