Fuel hose gore

[furgo]

Good thing I was looking at the starter wiring and I cleaned up the cables and fuel hose in passing... to discover the outer rubber layer was peeling off.

I finally got around to replace it, and here's a picture for the hall of shame of what the return line hose looked like:

Let this be a reminder again for folks to check the state of their fuel hoses.

This is also a good opportunity to do a post-mortem:

Hose properties:
• 7.5 mm ID x 13.5 mm OD
• Inner NBR (nitrile butadiene rubber) + (textile?) braid inlay + outer CR (chloroprene rubber)
• Euro-spec: DIN 73379-1-2A-compliant (guessing SAE J30R7 equivalent or less?)
• Unknown manufacturer
• Length of this return section: 400 mm. My '79 bus should have had a metal line here, but it was replaced at some point with rubber all the way to the tank.
• Last replaced end of 90s (at a guess)

Hose status:
• Outer layer ripped completely on one side and literally peeling off
• Small cracks all over too. Seems it must have started as cracks, through which the outer shell burst off.
• Inner layer looks ok to my (untrained) eye: no cracks, even at the ends.
• The hose remains elastic. I've seen some petrified hoses, and that's not one of them.

Other notes:
• After being reimported to Europe in the 90s the bus was driven in Germany and Spain. Ethanol content 5-10%
• The hose is located just above the passenger side heater flap box, but it curves to avoid it. In any case, the driver's side heater flap is stuck closed, and I'm pretty certain the heating has not been run in the last 10 years, so heat should not have been an issue
• Replaced it with Cohline 2240.0600 FI fuel hose: 7.3 mm ID x 13.5 mm OD, FPM/ECO inside + Aramid braiding middle + abrasion-resistant ECO outside. Suitable for fuel with ethanol content, DIN 73379-3E-compliant (SAE J30R9 equivalent?)

To be honest, I'm not sure what could have caused the outer layer fail so spectacularly. To the best of my knowledge, it was not exposed to massive amounts of oil or fuel externally. I said it was covered in dirt, but it was mostly mud from the road. Possibly fuel permeating from inside out, then?

On another note, would someone have the diameter of the FI tank nipples (in mm) handy? I had to really really tighten the 13 mm clamp I used there so that fuel stopped seeping through the end of the hose. I used stainless ABA clamps with raised borders, but still, that one had to be so tight that got me slightly worried. So I'm just wondering if the fuel tank nipples' diameter its smaller than the rest of 8 mm metal lines.
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'79 Westy, P22 interior, FI 2.0 l Federal, GE engine (hydraulic lifters)

Decode your M-Plate

[mainstreetprod]

I've noticed that the outer layers of even the recommended fuel hoses are not very resistant to fuel. I replaced all my hose with the Gates FI hose rated for 100 lbs plus, and whenever I change the fuel filter and fuel runs down the hose, the outer later quickly dissolves and gets all over my gloves. Inside is holding up fine though.

[TomWesty]

Gates recommends not using 30r7 on return lines in their tech tips. They recommend 30r9 instead. I try to find gates Barricade to fit in any application I have.
_________________
If you haven't bled on them, you haven't worked on them.
Visit: www.tomcoryell.com and check out my music!

[rockerarm]

[The Fez]

[babysnakes]

I haven't had any issues with my Gates Barricade in 20,000 miles yet. I'm up for a total inspection soon so we'll see then.

[rockerarm]

[pbenn]

I ordered some good hose from England this year, from Advanced Fluid Solutions.

It's supposed to be ethanol safe. They can size to the half mm.

https://www.advancedfluidsolutions.co.uk/petrol--diesel-fuel-hose-inc-hoses-for-bio-fuels-89-c.asp

[lintbrush]

[Q-Dog]

Are you seriously questioning why nearly 20 year old hose has failed?
_________________
Brian

'69 Dune Buggy
'69 Beetle Convertible
'70 Beetle

[busman78]

Amen to that, twenty years, I would buy that brand/spec hose again for it has proven it works.

[busdaddy]

[furgo]

That's why decided to buy hoses from known manufacturers and a datasheet available.

In any case, the purpose of the initial post was not to recommend or compare different brands or makers (there's the Fuel line fuel hose FAQ for that), but rather to show some common failure modes and again bring some awareness on inspecting and/or replacing the fuel lines at a regular cadence.

My bus had a mixture of hose types, here's the rest for the supply line.

Tank to fuel filter:

- Unknown maker, DIN 73379-E (not 3E) hose
- Held up pretty well, but due for replacement because of the cracks at the ends

Fuel filter to fuel pump:

- Held up astonishingly well, looks like the factory hose?
- No cracks at all, still flexible and going strong
- The only reason I replaced it was to have a consistent brand of hose across all the line

Fuel pump to fuel rail:

- Unknown maker, no markings at all
- Other than the usual cracks at the end, held up pretty well too
_________________
'79 Westy, P22 interior, FI 2.0 l Federal, GE engine (hydraulic lifters)

Decode your M-Plate

[tootype2crazy]

Sigh, another fuel hose thread. Just get this and be done with it, there is nothing better, not even gates, and it's metric.

https://www.belmetric.com/multifuel-hoseethanol-approved-c-14_662/
_________________
air-cooled or nothing for me
1978 Sunroof Deluxe Bus (daily driver)
1978 Transporter (mom's, making into a camper)
1970 Single Cab 2.1 turbo/EFI 6 Rib, 78 front beam, vanagon backing plates on rear (project)
2001 GTI VR6 (wife's)

[furgo]