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.. another question about tank breathers
02GF74 - 17/3/06 at 01:58 PM

What I have is a steel tube poking out of the top of the tank with what appears to be an 8 mm microbore compression fitting elbow onto which a hose tail and hose attach.

I would like to replace it with something that does not stick up so much so I have got an 8 mm compression end fitting.

there are 2 plans.
a) fit that and drill a 1 mm hole in the side to vent
b) fit and drill a hole in the side and solder in a brass tube onto which goes some pvc tubing.

I am not sure a) is too clever as although the hole is small, there will be fumes around whereas b) will allow them to exit at the bottom of the car.

Any comments?, seems as I think about it more, it has got to be be b).

... and no mention of demon tweaks or thinkauto breathers.

[Edited on 17/3/06 by 02GF74]

DarrenW - 17/3/06 at 02:37 PM

Can you not use th epipe that is already there, without the compression fitting and fasten some hose onto that?
If it is in the wrong place blank it off and put another one in more convenient position (b).

I fitted a fish tank one way valve to the other end of the hose on mine and fitted it high up out of the way. Valve was less than 2 quid. Air can go into tank but fumes and petrol cant get out. Dead simple.

rusty - 17/3/06 at 02:40 PM

I have been thinking about this probelm and I think I will run vent pipe from outlet on the top of the tank to a connection on the fillet neak and have some sort of vented cap.

No sure if this is ok.

02GF74 - 17/3/06 at 02:48 PM

quote:
Originally posted by DarrenW
Can you not use th epipe that is already there, without the compression fitting and fasten some hose onto that?
If it is in the wrong place blank it off and put another one in more convenient position (b).

I fitted a fish tank one way valve to the other end of the hose on mine and fitted it high up out of the way. Valve was less than 2 quid. Air can go into tank but fumes and petrol cant get out. Dead simple.


the compression fitting turns the pipe sideways instead of up; eventually there will be a floor above all this stuff. (the old ply floor had a chunk cut out for it).

I guess what I am really asking is the vented fitting with no pipe safe, a) above.

Now that someone mentioned it, I did consider fitting a vent to the big filler pipe or inlde on the tank. (I could then plug the tank vent using a bolt/copper washer sealant).

DarrenW - 17/3/06 at 02:56 PM

Personally i wouldnt vent to atmosphere so close to the tank without a non return valve in there. Nothing to stop the fuel surging and splasshing out (SVA fail as well as the obvious other reasons). At the very least fit a small length of tube and a valve.

I dont see why you couldnt put a small pipe into the fuel filler flexi. As long as it seals (ie fuel doesnt leak out of the vent tube when you are filling up) and has a valve it should be fine. Im sure this is how the Mk1 golf was vented. It had a steel filler pipe from body to tank with a small take off near the top.

rusty - 17/3/06 at 03:36 PM

I was thinking of the one way valve idea but I am worried about expansion as the car will be doing a lot of sitting around.

I'm not sure but I think I have sean caps with a foam seal os they will let pressure by.

On some cars thet is just a big coal of pip higher than the tank that then vent to air.