Date: 22-07-17  Time: 21:43 PM

Author Topic: Dropping gas from tank breather hose  (Read 375 times)

j0nes

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Dropping gas from tank breather hose
« on: 18 May 2017, 07:29:03 PM »
Hello. My bike built pressure to the tank. I removed the tank and blew air to all the hoses. Now it doesn't build pressure anymore to the tank but now its dropping gas from the tank breather hose. So there are two breather hoses and one goes to tank cap. Where that other hose goes? How it can drop gasoline from there?

bandit

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Re: Dropping gas from tank breather hose
« Reply #1 on: 18 May 2017, 07:58:09 PM »
When you refitted the fuel tank did you give the three black hoses a good tug down to make sure they are not kinked,these are found hanging down underneath the bike below the right hand side foot peg.
Make sure you always give them a tug after fitting/lifting fuel tank as pressure can build up in the tank & you could get a face full of petrol when you open the tank filler. 

Fazerider

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Re: Dropping gas from tank breather hose
« Reply #2 on: 18 May 2017, 11:44:07 PM »

The hoses connect to pipes that run up through the tank to the cap recess.
One terminates there and drains any rainwater from around the cap. The other goes to a nipple that seals against the cap itself which connects to the inner part of the cap. That is the breather.
Since both pipes pass through the tank, if either is perforated (by rust for example) then it’ll leak fuel.

j0nes

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Re: Dropping gas from tank breather hose
« Reply #3 on: 19 May 2017, 09:26:30 AM »
I blew some air to both of the pipes and its leaking from that rainwater pipe. I can just block that hose and its fine? Rainwater just stays under the cap and it will probably rust even more.


« Last Edit: 19 May 2017, 09:29:42 AM by j0nes »

bikemad

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Re: Dropping gas from tank breather hose
« Reply #4 on: 19 May 2017, 10:07:41 AM »
Try blocking cap end of either pipes with your finger whilst pumping air in other end,to see if air bubbles though your petrol if yes then your tanks toast cos the inner pipe/s rusted though 😬
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Fazerider

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Re: Dropping gas from tank breather hose
« Reply #5 on: 19 May 2017, 01:18:05 PM »
Yes, stuffing some water and petrol resistant sealant in to block the pipe top and bottom should work OK.. at least as a short-term solution.

bikemad

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Re: Dropping gas from tank breather hose
« Reply #6 on: 19 May 2017, 02:21:25 PM »
Yes, stuffing some water and petrol resistant sealant in to block the pipe top and bottom should work OK.. at least as a short-term solution.


I'd be careful blocking up pipes if tank cant breathe engine will not run !
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Fazerider

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Re: Dropping gas from tank breather hose
« Reply #7 on: 19 May 2017, 03:55:37 PM »
Yes, stuffing some water and petrol resistant sealant in to block the pipe top and bottom should work OK.. at least as a short-term solution.


I'd be careful blocking up pipes if tank cant breathe engine will not run !
It's the filler cap drain, not the breather.

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Re: Dropping gas from tank breather hose
« Reply #8 on: 19 May 2017, 04:18:42 PM »
jOnes - You will find the tank didn't build up pressure, it dropped it.

IF the breather pipes get kinked by not pulling them down properly when you lower the tank and whay you thought was a hiss of air coming out when you opened the tank was actually air going in.

DO NOT block any of the pipes.
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daviee

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Re: Dropping gas from tank breather hose
« Reply #9 on: 19 May 2017, 07:44:53 PM »
you can block the water drain that will not affect the tank breathing just make sure you block both ends as rain will get into your tank / petrol if its a perforated tube if its the other breather you can block that but you need to remove the rubber washer so the cap can breath at the top at the tank cap this is not the best but will give  you  time to either get another tank or put in a separate breather

darrsi

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Re: Dropping gas from tank breather hose
« Reply #10 on: 20 May 2017, 10:41:48 AM »
Still sounds like a 'new' tank to me.
Interesting seeing your photo though, i put a photo of my slightly newer tank on here a while back and you can see how theyimproved the drainage holes around the cap area.
Any of the tanks will fit your bike by the way.

98/99 18 litre
00/01 20 litre
02/03 22 litre

The latter tank will be a slightly different shape, but only on the upper part, it will still sit okay where it matters lower down.
Only thing is you still have pipes going downwards, whereas from 2000 onwards they fitted a rubber cup for the small metal excess/vent pipes to sit in to. It just means you don't get the possibility of kinked pipes when removing or lifting the tank.
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bikemad

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Re: Dropping gas from tank breather hose
« Reply #11 on: 20 May 2017, 11:35:04 AM »
I might have a spare rubber cup I'll have to check ? & I did change one over that had tubes,what a faf removing the tank with pipes on its easy to hinge up once the mod is installed 👍
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Re: Dropping gas from tank breather hose
« Reply #12 on: 20 May 2017, 06:28:34 PM »
You could try running a petrol resistant pipe up through it and seal the edge at the bottom end between the pipe and the tank.

j0nes

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Re: Dropping gas from tank breather hose
« Reply #13 on: 20 May 2017, 10:34:41 PM »
I just blocked that rainwater pipe. It's working fine. I keep my bike in garage so it can only get water in the tank when i wash it. If that breatherpipe starts to leak, that is a problem.