Rear fuel line replacement options

[belms4]

Hey all! So as part of my full restoration/widebody build I'm looking to gather some info and hear what others have done with the rear fuel lines. Particularly, I'm interested in the 3 lines pictured that run from the fuel tank lid and around the fuel filter. I'm looking to hear about full replacements for these lines or some sort of hybrid solution maintaining part of them.

For some background there are 3 lines here. 2 of which attach directly to the blue lid on top of the fuel tank. 1 feed line runs from that lid with rubber hose crimped to plastic line that has a banjo fitting and feeds into the fuel filter. The other attached to that lid is the longer one that is a return line with a rubber hose crimped on each end and attaches directly to the harder fuel lines that run the length of the car up to the engine bay. The 3rd small one has a banjo fitting that attaches to the exit of the fuel filter and then runs the small length to crimped on rubber end attaching to the hard lines running to engine bay.

All of these lines are discontinued from Audi. I think maybe 1 is available through Tradition, but 1 isn't much help. I've chatted with another member on here who has some ideas, but want to see what others have come up with for replacement of these lines. As far as full replacement solutions go I wouldn't be opposed to something using an aftermarket style fuel filter that dumps the banjo fittings and similar to the fuel line/filter product THE-Tuner sells, but I really only need half that kit. Definitely don't need 2 fuel pumps and would like to keep the oem fuel tank lid with line connections. Link for reference:

http://www.the-tuner.com/en/product/...filter-system/

I found this thread that has some good sources for connectors and a kit. I could see some parts being of use. Really I'm looking for replacement solutions for just the fuel lines pictured here in the rear and leave everything from the hard lines forward as original.

https://www.audizine.com/forum/showt...lacement-parts

I did bring these 3 lines to a shop today that can recover the fittings. Once they saw the lines were plastic they said there isn't much they can do with them short of replacing the plastic sections with rubber fuel hose, then they could recover the fittings.

Thanks everyone!!



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[CELison]

Not sure how helpful it is, but I replaced the hardline from the filter exit to the rails with areoquip -6. You can get whatever fittings you want for that line and it will attach to any stock hardline with a factory barb fitting. You sure those are plastic? All the other fuel hardline isn’t, but it looks like it is. The areoquip stuff bends easily too and is safe for E. They make a took to get the fittings on the hose, but I found the easiest way to do it is to soak the end of the stove in some hot water for 5 min then press the fitting in by hand.

[belms4]

Yeah these lines are 100% plastic, sorry the pics may make it look like they're painted hard lines. It's like something between the hard lines and the rubber lines. Very flexible, but also makes the fittings on either end basically permanent where the plastic line can't be reused if I did remove the fittings. I'll have a look into the aeroquip lines you mention, but I think what you're talking about are the lines forward on the car from these ones I'm looking at. Which if they have a barbed connection may be something more standard I can move to for this setup.

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[PwrWgn]

Isn't that Polyamide line? Should be stenciled on the side with "DIN 73378" or similar.

Polyamide is used in a couple places on this car such as the fuel lines and PCV (spider hose).

I don't know how to form this tubing into the bends but to connect it to a barb fitting apparently it's pretty straightforward and tutorials are available. I'd be curious if you could form one with a bender sort of like brake line (plus maybe a heat gun).

Belmetric sells it in various diameters: https://belmetric.com/m8x10-black-po...x10-3011-0810/

They also sell crimps/collars that you'd need to complete the assemby: https://belmetric.com/fittings-plugs.../hose-collars/

I'd love to find a local shop that could do the "10 point" Eckstein crimps that would replicate the original...but I doubt thats very common.

[belms4]

I think it's pretty close to what you've linked there. At least based on the markings it would seem to be a polyamide/polyvinylidene fluoride mix (not that I knew what that was before looking it up!)

Your links there bring me to another thought looking at these... each line has 1 thing in common and that's a straight section with rubber line at at least 1 end. I can chop that and whatever length of plastic line I cut I could add that length back in new rubber line so they don't get shorter. Just need the right size barb to go into where I cut the plastic lines and crimper for new rubber hose. I don't mind reusing the plastic lines at all since they're in perfect shape. It's more the ends with crimped on rubber hose starting to degrade.

If I had to guess I'd think a heat gun around the plastic ends before a new barb goes in would do the trick.


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[PwrWgn]

Ah interesting, so PA12 I think represents Polyamide - but the PVDF makes it more like a blend instead.

Good point on the re-use of them - I'd think you could apply the same technique that Belmetric suggests to install this hose over the barb: https://www.youtube.com/watch?v=RSR-...ature=youtu.be

Not sure what the fuel hose type is there, but you can source the metal crimp collars pretty easily and inside the crimp joint there should be some type of barb-to-barb adapter that you can salvage.

[belms4]

Ah interesting, so PA12 I think represents Polyamide - but the PVDF makes it more like a blend instead.

Good point on the re-use of them - I'd think you could apply the same technique that Belmetric suggests to install this hose over the barb: https://www.youtube.com/watch?v=RSR-...ature=youtu.be

Not sure what the fuel hose type is there, but you can source the metal crimp collars pretty easily and inside the crimp joint there should be some type of barb-to-barb adapter that you can salvage.

Nice, that video is even simpler than I expected. The hot water dip is smart to minimize heating and warping more than the tip of the line.

Now just to size the right crimp pieces and get some rubberized fuel line. This should turn into a nice DIY on how to basically rebuild these original fuel lines for reuse. Probably a 1 time deal or you'll start ending up with larger sections of rubber fuel line than ideal. So we'll revisit this again in another 20 years lol.

I'll update this thread once I dig into these lines and have the right pieces in hand. I appreciate the input, this was a big help!

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[R490]

I got mine used from RSCarparts.de.

The banjo fittings can be reused with custom done lines.