Petrol fumes

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DaveW
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Petrol fumes

Post by DaveW »

Since the weather has got colder I've become aware of fumes in the boot. Seems to be from the flexible hose between filler and tank. New silicone hose. Jubilee clips all good and tightened. Anybody had a similar problem? Thank you.
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Re: Petrol fumes

Post by myoldjalopy »

Are you sure the fumes are coming from the flexible hose? It could be the seal in the petrol cap is past it and allowing fuel to escape and dribble down the filler pipe. Or the petrol gauge sender unit gasket is leaking. Search this forum for other posts on fumes in the boot - plenty of discussion on the subject over the years.
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Re: Petrol fumes

Post by panky »

A lot of silicon hoses are only petrol resistant and if exposed to liquid they will sweat. I had a similar issue on my Commer camper and a new fuel proof hose cured it.
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Re: Petrol fumes

Post by DaveW »

Thanks for replies. I am pretty sure it's from the flexible hose although I've ordered a new sender gasket this morning anyway. I'm a bit unclear about comment on Silicon hose. I've ordered a new one of those as well. I assumed they were the best type to have. What is a petrol proof hose please?
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Re: Petrol fumes

Post by panky »

What it says on the tin, it won't be affected by petrol to the point it weeps. If your hose was sold as petrol proof then I would ask for a refund. I was quite annoyed when the silicon one leaked fumes as it wasn't cheap so I bought a conventional reinforced rubber one instead, no more fumes so we'll see how long it lasts.
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Re: Petrol fumes

Post by DaveW »

Thanks for comments. I've now ordered a rubber hose as well and will try that.
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geoberni
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Re: Petrol fumes

Post by geoberni »

It seems odd that you're noticing fumes more as the weather has tuned colder.

The Flash Point of Petrol is about -40C, so above that it is evaporating, but the warmer it is, the more fumes.

I'm more inclined to think it's actual leakage/weeping somewhere; perhaps the tank overfilled and fuel sitting in the Filler Hose, or as others have said, the filler cap or tank sender gasket.
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DaveW
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Re: Petrol fumes

Post by DaveW »

Thanks again all. Fyi having got wooden floor out and stuck my head in there properly it is definitely coming from the filler hose and not the sender unit.
I received the new Silicon one from ESM today( prompt as ever) but they haven't got rubber ones in stock at mo. Got to decide whether to wait or fit what I've got for now.
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Re: Petrol fumes

Post by myoldjalopy »

You might as well fit it and find out while you are waiting - doesn't take long....
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rocco
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Re: Petrol fumes

Post by rocco »

I have had the same problem. Strong smell after filling up at the petrol station so as suggested, it is either the hose or sender unit cover gasket. I've bought both new and may finally get to fit them this coming weekend.
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DaveW
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Re: Petrol fumes

Post by DaveW »

Still wittering!
The new Silicone hose has made no difference. It's obviously not had fuel passing through it as I only put it on yesterday. I can only assume the fumes are seeping out of the ends. What are thoughts about a little gasket sealant around the filler pipe and tank neck?
Been looking for local source for a fuel proof hose. Can you still get "proper" rubber hoses any more?
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rocco
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Re: Petrol fumes

Post by rocco »

I've not had a look under mine yet but one must assume that the fumes can only leak from the holes in the tank. If you've thoroughly covered the two areas above then it might be time to look below. It looks like there might be a drain bolt under them.
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svenedin
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Re: Petrol fumes

Post by svenedin »

In all the time I have had my Morris (35 years) it has persistently had a smell of petrol in the boot.
Over the years, I have had a new petrol tank, changed the filler hose (rubber and silicone), changed the sender gasket (and the sender as well when that failed), replaced the gasket in the filler cap. Nothing has remedied the smell except the new tank did improve things as the old one had pinholes.

I have on hand, but have yet not fitted an alternative neoprene sender gasket but other than that I am out of ideas.

As the filler cap has a vent hole there will always be a slight smell of petrol around there but I can't explain why I am unable to sort out the main problem.

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DaveW
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Re: Petrol fumes

Post by DaveW »

Thanks again all. Now had a really really close crawl all round and under, with a mate. We can find absolutely nothing amiss. Everything looks in good order and no sign of actual leaks anywhere. Still a slight odour if I sniff right up against the ( new) filler hose. We concluded that it's probably always been like this and I've only noticed it recently because I've been generally tinkering to get to know the car.
I am going to drain the small amount of fuel now in the tank, rather than brim it, for the next couple of months while not wanting to use the car. I might get a new tank in the spring as part of plans to generally to get the old girl as good as I can. Again, thanks all. Appreciate the comments posted.
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rocco
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Re: Petrol fumes

Post by rocco »

I would have thought it would be better to leave a full tank of fuel over winter, to prevent rusting. It's what I do with my motorbikes anyway.
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Re: Petrol fumes

Post by Old_Robin »

Seems a common issue, BO with Morris minor Series 2 (1955) split screen.

On investigation I found that the lovely ethanol had played havoc with the filler tube (original or original design relacement). Now fitted a silicon one and we will see if this cures the issue....
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geoberni
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Re: Petrol fumes

Post by geoberni »

Old_Robin wrote: Fri Aug 15, 2025 10:18 am Seems a common issue, BO with Morris minor Series 2 (1955) split screen.

On investigation I found that the lovely ethanol had played havoc with the filler tube (original or original design relacement). Now fitted a silicon one and we will see if this cures the issue....
I wouldn't immediately jump on the Blame Ethanol Bandwagon..... :roll:
For a starter, Ethanol was widely used in the 1930s-70s, without any concerns....research Cleveland Discol.
Cleveland Discol Advert 1937.JPG
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.
Nothing about these cars was particularly intended to last 10-20 years, let alone 70!

My SII was very like that when I brought him in 2017...
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myoldjalopy
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Re: Petrol fumes

Post by myoldjalopy »

Yes, those old tubes have deteriorated over many years service. I had to replace mine a few years ago...must have been well over 60 years old at the time......
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