Don't like the adverts?  Click here to remove them

Fuel Tank Breather - HDJ80

G

Guest

Guest
Since Salisbury Plain, I have noticed that I am getting a sucking sound
when I open the fuel filler cap, so I guess that the breather must be
blocked.
I haven't yet crawled underneath to find it, but am wondering:
(a) Where is it?
(B) Have any of you considered extending the breather along with the
diff and tyranny breathers to prevent it getting blocked with mud or
sucking up water?
Roman, I noticed that you posted a couple of queries about this on the
80s list, but without much response.
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift, ARB
 
Julian Voelcker wrote:
When you find it; cutting the pipe at a steep oblique angle helps. I
ride dirt bikes and this happens to the carb breathers which dangle down
near the ground. It doesn't prevent them blocking totally but does help
quite a lot and I have never had them block myself despite traversing
bogs etc. Having free length so they bend away from the direction of
travel too. On the fuel tank breathers which only need to pass one way
we use non-return valves and site the pipes carefully in the hope that
when you fall off you don't lose all the fuel. Of course on a Cruiser
you could move the pipes a lot more freely I expect as they hopefully
don't end up on their side quite so often as bikes!
Ian.
--
Free classifieds for anything 2 wheeled:
http://www.fud.f2s.com/classifieds/classifieds.php
Layman's ROW guide: http://www.rightsofway.net
 
On Mon, 13 Dec 2004 10:21:41 GMT, Julian Voelcker
<[Email address removed]> wrote:
Hello Julian,
I guess you have found it by now (I check my email every few days now,
being away from home).
I have connected the tank breather to a manifold fitted above the rear
axle that also takes pipes from the rear axle and diff lock.
The 80scoll replies were relevant to petrol models which have a
different system - not realy useful for diesel tanks venting.
--
Rgds,
Roman (London, UK)
'92 HDJ80
 
Hi Roman
Could you explain what the purpose of the breather is, where it is and all
that technical stuff.
Thanks
John c
92 HDJ 80 Ireland
----- Original Message -----
From: "Roman" <[Email address removed]>
To: <[Email address removed]>
Sent: Wednesday, December 15, 2004 10:35 PM
Subject: Re: [ELCO] Fuel Tank Breather - HDJ80
 
I'd be interested too. When I asked this question on 80scool I was told not to worry, but I get the sucking (or blowing?) noise too when the tank is very empty, and I do worry a bit about it.
Christopher Bell
 
You guys need to be carefull, I buckled a nylon tank on a peugeot 406
a few years ago because the service mechanic didn't check the breather
when asked. Needed a new tank.
Regards, Clive.
HDJ81
2.5" OME
ARB lockers
On Thu, 16 Dec 2004 09:41:09 +0000, Christopher Bell
<[Email address removed]> wrote:
 
Don't like the adverts?  Click here to remove them
Clive
I know. That's why I'm worried. I've since had a look at my Haynes manual and it suggests that the breather is attached to the sender assembly, which can be got at by "removing the middle seat". Er, I've got two middle seats. I suspect there is an access hatch in the floor - a job for the weekend.
Christopher Bell
 
Christopher,
Until you can fix this properly just leave the filler cap
slightly loose when you fill up, the fuel will not leak out but the
air will escape if it needs to.
Regards, Clive.
On Thu, 16 Dec 2004 19:01:27 +0000, Christopher Bell
<[Email address removed]> wrote:
 
On Thu, 16 Dec 2004 00:03:44 -0000, john byrne <[Email address removed]> wrote:
Hi all,
Venting (of a fuel tank, diff housing, transfer box, etc.) is there to
prevent pressure/vacuum inside a closed chamber. Without it, internal
pressure caused by heat would force fluids past the seals. On the
other hand, the cooling down of a chamber would cause suction, letting
in moisture/water.
Contrary to petrol models (which due to environmental reasons have a
charcoal filter in line), fuel tanks in diesel models are vented
straight into the atmosphere.
On my LC I found a piece of rubber pipe sticking from the top of the
tank (near the left leg of the frame), running towards the back of the
car. I can't check now if originally it had some sort of endpiece /
check valve, but this is not important at this stage. This pipe, like
the other breather pipes can be extended to a higher point, e.g. up
the bulkhead in the engine compartment. It is just as easy to run the
pipes higher up, e.g. along the snorkel pipe.
One thing to note is that a diff or gearbox can get cooled pretty
quickly when it gets submerged in water, hence a breather tube must
have sufficient internal diameter.
Although the fuel tank does not get hot/cold as quickly as the other
bits, it still needs to be vented to avoid vacuum when fuel is
gradually removed from it. Pressure caused by fuel expanding due to
hot weather is less important. Typically, there is a check valve in
the filler cap and/or breather tube. Some people don't think it's not
important to extend this tube but after all it's quite an easy job
that will prevent situations mentioned in the other posts.
--
Rgds,
Roman (London, UK)
'92 HDJ80
 
Back
Top