Fuel tank breathers question

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chewbacca
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Fuel tank breathers question

Post by chewbacca »

Hi guys.
Anyone know why the breathers on the fuel tank are rubber, into plastic pipe, into rubber?
Why not just single run of rubber?
Cheers

E D I T - the 4 pipes to the 2 breathers tanks, not the one over the top of the main tank.
B plate 1.9 petrol bus

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Re: Fuel tank breathers question

Post by ghost123uk »

Mine had simple rubber pipes to the breather tanks (fitted by me) for most of the time I owned it (~13 years) with no ill effects to report.
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Re: Fuel tank breathers question

Post by shepster »

I've took mine out and capped the ones off on the tank, never had any problems.
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Re: Fuel tank breathers question

Post by chewbacca »

Sounds like swapping it all for runs of rubber pipe is a win currently then
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Re: Fuel tank breathers question

Post by crazyhorse »

shepster wrote:I've took mine out and capped the ones off on the tank, never had any problems.

So these dont run to the breathers??

Interesting. Do you still have the tanks in?? I thought you had to have them, vapour and air space and all
Last edited by crazyhorse on 02 Apr 2018, 07:46, edited 1 time in total.
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itchyfeet
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Re: Fuel tank breathers question

Post by itchyfeet »

use 100% ethanol pipe and you will be fine but at 11 quid a meter it will cost more, my guess is VW used plastic because it's cheaper and more durable.

https://www.brickwerks.co.uk/fuel-hose- ... m-eco.html" onclick="window.open(this.href);return false;

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Re: Fuel tank breathers question

Post by Aidan »

the plastic pipes are originally clipped to the body before the tank and breather tanks are fitted so hose is just for connection to the plastic pipes, it's for ease of assembly in production, after 20plus years the clips will generally be broken so the plastic pipes appear to be loose but then the benefit is the plastic pipes are less prone to vibration wear than loose hose is so they don't tend to get holes where they run over the edges of the chassis especially as the edges of the chassis become corroded and rough

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Re: Fuel tank breathers question

Post by shepster »

crazyhorse wrote:
shepster wrote:I've took mine out and capped the ones off on the tank, never had any problems.

So these dont run to the breathers??

Interesting. Do you still have the tanks in?? I thought you had to have them, vapour and air space and all

Tanks are gone and pipes capped off, the ones across the top of the fuel tank are still in place.

I believe they were for very hot countries when you have a full fuel tank due to the 'valley' down the centre, and as said, expansion.

Not really a problem here I guess, plus at the rate these vans guzzle petrol they're not full for very long!
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Re: Fuel tank breathers question

Post by R0B »

Petrol :shock: Wash your mouth out. :)
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Re: Fuel tank breathers question

Post by crazyhorse »

shepster wrote:
crazyhorse wrote:
shepster wrote:I've took mine out and capped the ones off on the tank, never had any problems.

So these dont run to the breathers??

Interesting. Do you still have the tanks in?? I thought you had to have them, vapour and air space and all

Tanks are gone and pipes capped off, the ones across the top of the fuel tank are still in place.

I believe they were for very hot countries when you have a full fuel tank due to the 'valley' down the centre, and as said, expansion.

Not really a problem here I guess, plus at the rate these vans guzzle petrol they're not full for very long!

ooo might do this when replacing tank later. These tanks do hold a lot of mud. Would be good to allow the arches to breathe

I only half fill also as I have LPG.

Any ideas where i can get the caps??
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chewbacca
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Re: Fuel tank breathers question

Post by chewbacca »

If they're capped off, won't you loose the tanks ability to breathe completely?
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Re: Fuel tank breathers question

Post by itchyfeet »

chewbacca wrote:If they're capped off, won't you loose the tanks ability to breathe completely?

yes but I guess it's not so much problem in UK
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Re: Fuel tank breathers question

Post by ghost123uk »

It will breathe fine through the rust holes in the central well :run
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chewbacca
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Re: Fuel tank breathers question

Post by chewbacca »

I've been thinking about this some more today.
In a simplified way, each corner of the tank is connected to atmosphere via the wheel arch tanks.
I don't actually get the need for the link pipe across the top of the tank. Since both sides of the tank are vented, the fuel will always sit level won't it?
The only time I could see the arch tanks having fuel in them is if the bus is on a serious lean for an extended period of time.

Don't most cars have a single breather stuck on the top of the tank? If so, to replicate this, could the 2 breathers on each side simply be linked together rather than fed to an arch tank, then have the centre pipe removed so there's a vent hole on the top of the tank on each side? If that would work, tank removal and refit becomes much easier, plus the 2 extra tanks could be binned.
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Re: Fuel tank breathers question

Post by mshaw1980 »

I would be interested on responses here as I am about to put a new injection tank in for my Subaru conversion and was wondering about these breather tanks?
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