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Smells of fuel but no visible fuel leak. Help please

Posted: 05 Sep 2017, 11:53
by Sailsy
Hi all,

I apologise for the length of this posting before I start. About a week before we were due to set off to Cornwall for two weeks my missus took the van to a local garage to get the rear facing (behind the front passenger seat) removed. We had previously discussed having this done so she thought she was being helpful by arranging to get it done as a suprise for me. Unfortuntely she didn't realise that the tank would have to be dropped to get to two of the four bolts through the floor. Fast forward a few days later I am packing the van ready to set off to Cornwall the next day and I start getting really strong wiffs of fuel. I rolled underneath with an inspection lamp and couldn't see any fuel leaks but the smell was pretty strong. Local heros "LVH engines and Restos" over in Heddon here in the NE agreed to look at it for me the next day (cheers Paul and Rob) and they couldn't see any of the breathers off or any issues with the fuel lines etc.

Since I bought the van two years ago it has had a new fuel tank, fuel lines, fuel pump, carb rebuilt by Bromyard, new sender and seals, new breathers etc. We decided that in the absence of any fault we decided to go to Cornwall but for the whole trip we kept getting wiffs of fuel most of the time and particularly bad after filling up. I spent the two weeks rolling back under the van on numerous ocasions checking there wasn't any visible fuel leaks.

The van went back to the local garage yesterday becasue I suspected that they may have disturbed a breather etc. and i thought it was their responsibility to put right whatever they had done. They called me yesterday and said they had dropped the tank again and all of the breathers were in place and intact and there weren't any visible fuel leaks. They even filled the tank headspace with a smoke machine and said there weren't any visible leaks from the breathers.

I collected the van last night and as soon as i got out when i got home I got another big wiff of fuel. Rolled underneath and still there wasn't any visible leaks. It didn't wiff until after the seat was taken out and the tank dropped but I guess there is a very small chance of it being coincidental but I doubt it.

I dont know what to do next. If I can smell petrol vapour there has to be some sort of leak in the system or am I missing something. Starting to wish the rear facing seat had never been removed.

Has anyone had a similar problem or any suggestions as to what to try next.

Cheers

Andy
:cry:

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 05 Sep 2017, 13:07
by sarahandthebear
The only thing I can think of I should the breather pipe but you have had all that changed. What fuel lines did you use may I ask also have you had the fule filter replaced other then that I personally have no idea but I'm sure someone on here will be able to help later

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 05 Sep 2017, 13:12
by itchyfeet
possabilities I can think of
1 the garage missed something and there is a pipe off or something split/broken.
2 they used a substandard filler seal when they changed it or they didn't change it and while it looks ok its not sealed
3 There are parts they didn't touch which they didn't check like filler neck.
4 they spilt petrol and there is still some in a nook or cranny somewhere.

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 05 Sep 2017, 17:05
by Sailsy
Hi Itchy feet

Didn't think fuel filler seal. I bet they yanked the filler pipe out and they wouldn't have replaced the seal. They aren't VDub types and haven't a clue.

They are also arsey apparently about fitting parts supplied by the customer claiming something about insurance wont let them, so even if I had supplied the new seal when I took it back they wouldn't fit it.

Makes a lot of sense that because the wiffy is most wiffy after filling up with all that fuel going past the knackered seal...

Cheers for replying with what sounds like the probable cause. :D

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 05 Sep 2017, 17:13
by CovKid
Filler neck seals rot out, as I discovered on mine: https://www.youtube.com/watch?v=xyEQSm5Ph2g&t=2s" onclick="window.open(this.href);return false;

Although smells only likely when filling to be honest - unless you corner like Damon Hill.

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 05 Sep 2017, 19:28
by fazzer
exactly same problem I have nothings out of place all fuel lines replaced but still smell fuel,ive also noticed a part of the wooden interior fittings next to the engine hatch has turned black like its burnt,but its not.Also when the heater is switched on the smell actually makes our eyes sting.I do intend having a good strip down and replace filler neck,and reseal exhaust.

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 05 Sep 2017, 20:42
by bigbadbob76
Mine smelled of fuel when the breather pipes came off the little tanks under the wheel arches.

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 06 Sep 2017, 08:38
by porthyt
I have he exact same. I have changed the tank, all the seals, the breather pipe, all the fuel line, the filter, the filler neck seal (all with Brickwerks parts) and I get the exact same issue. Whiffy after fill up and sometimes on corners. No visible leaks.

Only started after I fully filled my old tank and got a strong petrol smell (that's why I changed it all) and hasn't stopped since.

Any ideas? Haven't changed the filler neck or the return line.

Cheers Josh

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 06 Sep 2017, 08:54
by itchyfeet
porthyt wrote:
Any ideas? Haven't changed the filler neck or the return line.

Cheers Josh

could be filler neck...or return line

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 06 Sep 2017, 11:40
by itchyfeet
There is a special tool for finding fuel leaks :rofl

ImageVW T25 rotation by Paul_Barr, on Flickr

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 06 Sep 2017, 19:46
by nevill3
Have they put the breather hoses back on correctly, including the ones to the two header/breather tanks in the wheel arches (they should each have three pipes attached (well mine have but it is a diesel)) If they removed the plastic header tanks when they dropped the fuel tank I know they are a pig to get back into place, I would check that they have not been forced and possibly cracked or damaged.

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 08 Sep 2017, 09:23
by Mr Bean
If it is anything like mine it is one hell of a job to stuff all the pipes into the holes etc. with the tank nearly in position, and almost impossible to see whether you have got it right. Maybe the for and aft water plumbing isn't right :roll: After a couple of attempts I got it to stop leaking but brimming the tank to check made me very uncomfortable bearing in mind that the engine is downwind to the tank (petrol) when on the move.

Incidentally I had discovered a problem while touring in Europe when I filled up on a sloping forecourt on an uncharacteristically cold morning and didn't twig the smell until we stopped later and the fuel had presumably expanded - not into the expansion tank/s.

CS

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 08 Sep 2017, 10:11
by ELVIS
Sailsy wrote:
They are also arsey apparently about fitting parts supplied by the customer claiming something about insurance wont let them, so even if I had supplied the new seal when I took it back they wouldn't fit it.

:D

I'm guessing it's to do with liability, or in this instance, shared liability and negating months of legal arguments in the event of a failure/issue. Maybe their insurance company has had previous issues so stipulate the clause.

We fit customer supplied parts but obvs the understanding is the labour will be billed to rectify any faults arising from a faulty part whereas if it's a part supplied by us any labour charges are waived.

HTH :ok

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 09 Sep 2017, 05:01
by kezza87
I Have exactly this problem too, I replaced every seal on the tank and all the breather pipes, even the valves on top of the breather tanks but I still get a slight wiff of petrol now and then. although I have never fully filled my tank yet as the van is permanently parked while being rebuilt. however I have noticed the smell is actually really strong coming out of the breather pipe which has the 'shrek ear' things on. I assumed it was normal?
or maybe the breather tank valves hadn't sealed as I haven't filled the tank to create pressure?

Maybe check your Breather tank valves as the ones I replaced were sticky with old fuel varnish so didn't seem to be working properly.

Re: Smells of fuel but no visible fuel leak. Help please

Posted: 08 Nov 2017, 13:04
by bigbadbob76
I had my battery out over the weekend and found a rusty hole under it.
I patched the hole and havn't had fuel smells coming into the cab since.
Got me thinking that removing the bulkhead may have left bolt holes in your floor Sailsy, which allow the smell from the fuel vents to get into the cab.