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Mon Jul 23, 2018 8:06 pm

The previous owner apparently broke the supply line off at the tunnel and just ran a line under the pan instead of fixing it correctly. I'm sure I'm not the only one to find this situation. I need to find a way to splice an inch or two ....steve

Mon Jul 23, 2018 9:16 pm

I replaced my whole line with 1/4" steel tubing. Comes in a roll and I fed mine in from the back. Straightening as I went.

You could just open the front access panel and do a slice in there I guess.

Mon Jul 23, 2018 9:48 pm

Sleeve the original and repair sections together with the next size up tube.

Mon Jul 23, 2018 10:21 pm

Steel SwageLok metric union

Tue Jul 24, 2018 5:46 am

First of all you need to determine if the existing line through the tunnel is even any good. There must be a reason the PO abandoned the existing line through the tunnel. I'd replace the whole thing front to rear and be done with it. It's not a fun job, but plenty of people have done it.

Tue Jul 24, 2018 7:07 am

If you are going to keep the 5mm rubber hose for your fuel lines (I assume you will- all the fuel stubs in stock set ups are 5mm. (or 5.5mm technically I guess)

I recommend running 3/16" metal hardlines. Reason being that 1/4" is bigger than 5mm and will stretch the rubber hoses to 127% of the manufactured diameter- which can cause tears and premature failure/fuel leaks. (unless you use 1/4" rubber hoses, but then these rubber hoses will be loose on the fuel pump, tank outlet, etc. by about 27% and can cause leaks if not securely clamped)

3/16" hardline is only slightly undersized (by 0.3mm to be precise) to the 5mm rubber hose and can be easily clamped tight to provide leak-free connections.

3/16"= 4.7mm
1/4"= 6.35mm

Just something to consider as you contemplate your options.

Tue Jul 24, 2018 7:09 am

How To: Metal fuel line replacement w/pics

https://www.thesamba.com/vw/forum/viewtopic.php?t=380724

Steven

Tue Jul 24, 2018 7:23 am

Another discussion of selection of and running the hardline in the tunnel:
https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

But here's the most salient part about selecting the size of the hardline in the tunnel:

AlmostHeavenWV_VW wrote: markeaton wrote: AlmostHeavenWV_VW wrote: If the line he has is SAE sizing:

1/4" is a little big (~6.35mm)
3/16" is slightly small (4.78mm)

I'd probably go 3/16 to match 5mm, just my opinion

But, I want the rubber to sleeve over the stainless line, right?
Yes the rubber will go over the hard line. By getting slightly undersized Outer diameter (OD) hardline, the 5mm hose will go on without stretch and damage. Just be sure to use proper clamps like these:
https://www.belmetric.com/high-pressure-screw-clamps-c-15_143/?zenid=lgbdpaacclkpou7tf6sfgorng2
http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=HOSECLAMP

If you use 1/4" (6.35mm)OD hardline, the 5mm ID hose will be very tight and will have to stretch to go over the larger OD. Stretching hose is not a good idea, see below:
bluebus86 wrote:
I prefer 1/4 inch outside diameter tube. either stretch the metric hose a bit, or use 1/4 inch hose. 1/4 inch hose will work on the factory fittings with clamps. I like it also cause of its availability and some meets SAE 30R9 standards which means it is inner lined with a teflon like material to protect the rubber from the effects of todays oxygenated fuels mandated for me to use. Metric, specially lined is not always stocked locally.

I disagree blue, for these reasons:
"Stretching" the metric hose to 120% of it's original ID is a bad idea, you are just asking for problems. Any 'stretch' is essentially creating small separations/tears/weaknesses in the hose- which will eventually crack and fail quicker(shooting gas everywhere) than properly sized & unstretched hose.

If you change to 1/4" rubber hose throughout it will be a full 1.3mm too large for all of the other fittings in the fuel system (tank outlet, fuel pump, carb inlet, etc) You will run a higher chance of leaks. Perhaps it will be fine, but with proper sized hose (which is also rated for up to E85 ethanol) readily available I can't see a reason to run 1/4" line (unless you are just roadside fixing to get home from a trip).
https://www.belmetric.com/multifuel-hoseethanol-approved-c-14_662/?zenid=lgbdpaacclkpou7tf6sfgorng2

Tue Jul 24, 2018 7:32 am

benchracer1 wrote: [img]The previous owner apparently broke the supply line off at the tunnel and just ran a line under the pan instead of fixing it correctly.
After you figure out the complexity of "fixing it correctly," I'm sure you will soon understand the reason the PO performed the fix they did :wink:
While I wouldn't run mine under the pan, I do have two hard lines running along my tunnel on the inside of the car, due to the original line being unusable, and needing a second for my fuel return on my FI system. There are graphics in the Bentley that illustrate where to cut in the bulkhead to do such a thing.

Tue Jul 24, 2018 7:57 am

Lots of cars run the fuel lines along the outside of the frame. As long as you use rubber lined clamps to fasten the tubing to the body it should minimize any chance of wear. Also, consider running it INSIDE the lip that runs around the edge of the floor pan. This reduces the amount of the tube that is exposed to road hazards.

Running it in the tunnel is best as it protects the line from external hazards and adds a layer of protection between the passengers in the cabin and the fuel line. This reduces the hazard to the passengers if the line has a leak. You really don't want raw fuel spraying the passengers.

If you plan to replace the steel lines, it doesn't hurt to go larger if you have any thoughts of adding performance options. Don't get me wrong, the stock 5mm lines can support engines up to 200hp, but larger 1/4" lines are easier to source and provide a small capacity improvement over stock.

Tue Jul 24, 2018 8:06 am

make sure you do not use copper tubing. it will not be safe, can easily fracture from vibration induced work hardening. use steel. I recommend against going with undersized tubing, go stock size or bigger to 1/4 inch. this will allow use of the metric hose or 1/4 inch hose. 3/16 is a bit too small if 1/4 inch hose is used. do not run a hose for this line either, susceptible to damage.

your best bet is thru the tunnel. Never ever ever run it along in the cabin.

I have done enough rough road, camping in the Bug to not want it strung under the pan, although there maybe somewhat good locations under there, the gold standard is inside the tunnel.

Bug On with gas!

Tue Jul 24, 2018 9:53 am

bluebus86 wrote: Never ever ever run it along in the cabin.
...why...? If it leaks turn off the car. Not like I would drive down the road for miles at a time with fuel spewing out of a line. I feel like "Never ever ever" is not warranted in this case.

Tue Jul 24, 2018 11:02 am

For what it's worth, the VW shop manual recommended running a fuel line through the cabin (like this)
That was for carbureted engines with the fuel pump pulling 3psi though, not sure that held true for FI pushing ~35psi.. a leak in the latter is significantly more problematic than the former.

I ran my replacement through the tunnel; wasn't the most fun (esp with the body on), but doable.
Used 1/4" steel brake line from NAPA, and all 1/4" rubber hose. Only 5mm connections now are the tank and the carb (got an electric fuel pump), gently snugged the hose clamps and haven't had any problems.

Tue Jul 24, 2018 11:20 am

The hard line is fine. I need to figure a way to splice an additional inch or two on. Being steel I'm not sure a compression fitting will work. Maybe a flare. As a last resort I could slide a piece of fuel line over that end and put it down the tunnel hole and fit a grommet around it. I'd much prefer solid line though

Tue Jul 24, 2018 11:27 am

Also one of the above posts showed the link being pulled out of the side of the framehead. Might be a thought

Tue Jul 24, 2018 11:55 am

benchracer1 wrote: The hard line is fine.
Tried to blow through it to see if it's clear?
If it hasn't been used in a long while and there was any gas left in it there's a good chance it's now full of sludge and unusable. 's also been open to water and dirt for a while.
Hopefully it's fine, but if you haven't yet I'd test it before putting any more effort into saving it.

Tue Jul 24, 2018 4:13 pm

kangaboy wrote: bluebus86 wrote: Never ever ever run it along in the cabin.
...why...? If it leaks turn off the car. Not like I would drive down the road for miles at a time with fuel spewing out of a line. I feel like "Never ever ever" is not warranted in this case.

I had three friends nearly incinerated by a ruptured thru cabin fuel line. Got hit by a truck, car buckled, line in cabin ruptured, gas everyplace, fire started in back in the engine bay, fire spread to cabin, then fuel tank. One friend was pulled out unconscience with his clothes on fire, the other too got out without burns other than superficial burns on their arms from pulling the unconscience person out of the car.

Thus a fuel line inside the cabin is a big safety concern.

Is it a high probability failure? Probably not, unless in a crash, although wet carpets can cause rust thru. Is the end result of a low probability leak of gasoline in the cabin a trival issue, heck no, the end result can be death, severe disfigurement. So for me it just plain ain't worth the risk, put it in the tunnel, use proper materials, make sure it is secured, grommented.

As far as VW stating a repair line maybe run thru cabin, as another poster states, .... Let's just say safety was not such a big concern back then. VW also sold plenty of Bugs without seatbelts, should we take no seat belts as being safe? In the tunnel is safer, why choose the less safe option? It is not very difficult to do it right.

Bug On Safely

Tue Jul 24, 2018 4:21 pm

benchracer1 wrote: The hard line is fine. I need to figure a way to splice an additional inch or two on. Being steel I'm not sure a compression fitting will work. Maybe a flare. As a last resort I could slide a piece of fuel line over that end and put it down the tunnel hole and fit a grommet around it. I'd much prefer solid line though

A flare union would be correct.

A hose hidden in tunnel, even if only the end of a hose is hidden in tunnel is not good. not readily inspectable, and hose needs frequent inspection, hose clamp tightening would be hard.

A compression fitting will also work, but general home plumbing brass fittings are not advised. A compression fitting must deform the pipe to work right. a steel pipe requires lots of compression to deform . the brass nut and end cant take the torque, and thus nut may split. They do make steel compression fittings, industrial supply places might carry that, not likely to find other than brass for use on soft copper pipe at Home Depot, likely no steel fittings at Home Depot, and steel fittings is what you need for steel pipe.

Bug On!

Tue Jul 24, 2018 5:29 pm

bluebus86 wrote: A flare union would be correct.

A compression fitting will also work, but general home plumbing brass fittings are not advised. A compression fitting must deform the pipe to work right. a steel pipe requires lots of compression to deform . the brass nut and end cant take the torque, and thus nut may split. They do make steel compression fittings, industrial supply places might carry that, not likely to find other than brass for use on soft copper pipe at Home Depot, likely no steel fittings at Home Depot, and steel fittings is what you need for steel pipe.

That's why I recommended SwageLok steel metric compression union for repair. SwageLok is used in chromatography for high pressures and tiny molecules like hydrogen and helium connections.

Tue Jul 24, 2018 9:09 pm

I think I'll look into swagelok. When it comes to fuel I'd like to do it right. Even though it's not a pressure line I think doing it correctly is a good idea.....steve. one other thought was a flare. Any thoughts?