Newbie Fuel Hose Question - PeachParts Mercedes-Benz Forum

Oldwolf · #1 06-23-2009, 08:03 AM

I am looking for some fuel hose for my 1993 300D, 2.5L.

The hose I need is under the hood, and is used from the metal fuel supply pipe to the primary fuel filter and pump and on to the injection pump.

The existing hose measures about 13mm OD and the supply pipe ID measures to be about 7.6mm.

I can get 7mm ID and 8mm ID from my parts store. One might be too small and the other too big. What size do you guys use?

toomany MBZ · #2 06-23-2009, 11:15 AM

Ask Phil at the buy parts button.

tangofox007 · #3 06-23-2009, 11:40 AM

Quote:

Originally Posted by Oldwolf

One might be too small and the other too big.

I have found that SAE 5/16" (approx. 7.9mm) works fine in lieu of the 7.5mm that MB often uses. Exact fit is not necessary when it comes to hoses.

tbomachines · #4 06-23-2009, 11:51 AM

Quote:

Originally Posted by tangofox007

I have found that SAE 5/16" (approx. 7.9mm) works fine in lieu of the 7.5mm that MB often uses. Exact fit is not necessary when it comes to hoses.

x2, and its about 80 cents a foot at most parts stores. Return lines/cigar hose is 7/16 I think, not sure.

Oldwolf · #5 06-23-2009, 12:12 PM

So then do you guys think that of the two sizes 8mm is probably too big and I should use the 7mm? I just found out they also have 7.5mm ID fuel line btw. That's probably the size I need I guess. My W124 diesel supply and return lines: about 7.6mm (0.30").

7.0mm = .276"
7.5mm = .295"
8.0mm = .315"
5/16" = .3125"

tangofox007 · #6 06-23-2009, 12:27 PM

Quote:

Originally Posted by Oldwolf

So then do you guys think that of the two sizes 8mm is probably too big and I should use the 7mm?

This guy thinks you are obsessing way too much over hose sizes. You don't need to measure rubber hose with a micrometer.

tbomachines · #7 06-23-2009, 12:31 PM

Rubber hose will stretch a lot. As long as it is snugly over the barbs and/or clamped down well its not going to leak or move. No biggie.

Oldwolf · #8 06-23-2009, 12:39 PM

Quote:

Originally Posted by tangofox007

This guy thinks you are obsessing way too much over hose sizes. You don't need to measure rubber hose with a micrometer.

HAHA! You probably are correct about me being obsessive. Funny thing though is I cannot find much info on W124 fuel line sizes.

Diesel911 · #9 06-23-2009, 01:03 PM

Here is a nice metric to inch an more converter site.

http://www.worldwidemetric.com/metcal.htm