Fuel leak (sometimes)

[droftardis]

Hey All. 

Bit of an odd one. We had the fuel tank replaced about 12 months ago. One thing we have noticed is that when we fill up, there is a leak under the van. If we don't fill up 100% (maybe like 70%) we don't have a leak. It's not a terrible leak (maybe a cup full or so). It'll leave for maybe 5 mins and then it's fine. I will have a look at the pipes etc, but someone mentioned that this is the "overflow" and it's by design, but I can't find anything online about that. 

Any thoughts etc. 

Thanks
 

[maxstu]

It should not leak. What reason for replacement tank?

Have a read....

https://vwt25.blog/2016/05/03/replacing-the-fuel-tank/

There are numerous rubber grommets holding overflow/balancer pipes into the top of the tank.
Were they all changed with new tank?

[droftardis]

We had a mechanic do all the work. We told them what the problem was so assumed they did all that was needed. We'll call them tomorrow and find out what the problem is (and dig up the old paperwork). THanks for the information. 

[simonmarsh]

As per the other response, to me it sounds like breathers / breather pipes or even gauge sender gasket? 

[randamonia]

Mine did this the other day. Filled the tank, came out from paying and noticed fuel leaking from the top of the tank. Same scenario, new tank about 9 months ago…the old one was rotten. In a week or so I have it booked in with the guy why fitted it to drop the tank and take a look.

[300CE]

Whilst the fuel tank is out it’s a good opportunity to clean around the tank area as it’ll be full of years old crud and then spray a decent amount of Waxoyl/Bilt Hamber prior to refitting.

[randamonia]

Mine did this the other day. Filled the tank, came out from paying and noticed fuel leaking from the top of the tank. Same scenario, new tank about 9 months ago…the old one was rotten. In a week or so I have it booked in with the guy why fitted it to drop the tank and take a look.

On mine it was the grommets for the breather pipes. Mechanic said they have collapsed. Ordered new ones from heritage parts as brickwerks only had aftermarket in stock, which is actually what was used originally with the new tank not so long ago.