Leaking fuel when tank full

[mariner]

Hi all. Had this problem for while now and can’t get to the bottom of it. I’ve had the fuel tank dropped, cleaned and re-painted. Grommets and filler neck seal have been replaced. Main fuel line is good.

But when I fill the tank right up I still get fuel leaking from somewhere. Filler neck is dry and tank is dry. It seems to run off and drop from the plastic casing around the two pipelines that come out of the top of the tank/filler neck area that I’ve shown in the pic. Do either of these two lines in the plastic hosing carry fuel? They look more electrical to me. Is there anywhere else obvious I could check? Cheers for any help. I know I could just half fill the tank every time but I’d like to get it right!

A035366C-B2B5-4724-8C8B-E386BF8AA9BA.jpeg (111.82 KiB) Viewed 670 times

[937carrera]

There should be two plastic bottles at the back of the front arches are breathers for the fuel tanks. The hoses perish / become dislodged and cause leaks.

Were they not replaced when the tank was done ?

https://volkswagen.7zap.com/en/rdw/typ+2+syncro/t2/1986-65/2/201-32000/

[mariner]

Thanks. Had a look at the plastic bottle and the pipe running down from it runs to nowhere. It’s about 30cm long and isn’t attached to anything. It’s dry so isn’t causing the fuel leak. The hoses I’m unsure about are the two that run down from the filler neck area and are covered by the plastic hosing. This seems to be where the leak is coming from. Cheers.

[937carrera]

Thanks. Had a look at the plastic bottle and the pipe running down from it runs to nowhere.

That's your problem........ the pipe runs nowhere, so the connections on the top of the tank are open toi atmosphere and to leak when full.

I'll try and find you a photo

[937carrera]

Some threads with photos

http://forum.club8090.co.uk/viewtopic.php?f=42&t=165109

http://forum.club8090.co.uk/viewtopic.php?f=37&t=164501

http://forum.club8090.co.uk/viewtopic.php?f=37&t=163356

[mariner]

Thanks for that. Had another look, and just to clarify - there are two pipes side by side running off each expansion tank. One of these runs to, and is connected to, the top of the tank, the other is the short 30cm one that isn’t attached to anything. What should this second pipe off the expansion tank be fitted to?

It doesn’t look like this is the fuel leak otherwise there would have been evidence of fuel running off the top of the tank as this where the end of the second pipe currently sits. The tank is dry and the fuel is dropping from the plastic hosing below at its lowest point - I think this is shown in the photo.

[937carrera]

There are two pipes on the bottom of each expansion tank, so 4 connections onto the fuel tank. Then the connections on the top are the external breather with the shreks ear trumpets on the end which are always perished.

If the 4 tank connections aren't connected you have a leak when full

Take a close look at this picture and have another read of the linked threads

[mariner]

Yep, sorry, with you now. The second pipe on both sides of the van seems to be missing the wider sleeve that fits over the pipe and attached to the tank - I’m assuming this what you mean by the shrek ears piece.

Thanks, this gives me an easy check when I next fill the tank.

[937carrera]

Shrek ears are at the bottom of the outer pipes in the picture, not connected anywhere and shown in the linked threads.

TBH I think you should be taking the van back to whoever did the petrol tank......they should have replaced / renewed them at the time, even if not actually present.