fuel overflowing problem

[NOLAW]

ok guys I noticed a similar topic a few posts down but not quite the problem im having, iv recently got the little monster going and iv filled it up twice, both times iv had the fuel overflow when it gets to the top and spill down the side of the car..luckily it was just in its primer state so I wasn't too fussed but the car will be painted in the next week and a bit so I really don't want this happening again as I don't want the paint getting affected..

now the cars and 1973 corolla and it never ust to do this (has been a looooong time since it was drivable) when it had the standard fuel tank but I have since installed a 60L jazz cell in the boot and connected it to the standard filler via silicon hoses and a alloy elbow, im suspecting it could be a breather issue? thought I would get a second opinion anyway or see if anyone else has had the same issue after installing a new fuel tank

heres a pic of the fuel tank setup

[thegreatestben]

Doesn't look like you've got the smaller diameter breather which went back up to the filler? Did it have one originally?

[NOLAW]

honestly I can remember mate, id probly have to check on another standard KE20

[Flannelman]

No breather. My '75 falcon has the same issue, just magnified by the fuel tank having the wheel well pressed into it. The air cant get out and so travels up the filler tube when filling up.

[NOLAW]

No breather. My '75 falcon has the same issue, just magnified by the fuel tank having the wheel well pressed into it. The air cant get out and so travels up the filler tube when filling up.

cool cheers mate, did you resolve the issue on your falcon in the end? so if im to fit a breather to it where would be the best place to run it from and too

cheers

[evil_si]

Top of the tank to top of filler tube

[wde_bdy]

Haven't looked at a KE20 for while but I thought they had a breather standard? May not have been needed with the vertical tank and a shortish filler pipe.
KP Starlet could be a good donor as they definitely have a breather up the top of the filler neck and might match your current fuel cap, then just need a breather hose picking up off a high point of the tank. Even modify the pipe where it goes into the tank, a small upside down cone tapering up to the right hose size should work.

Callum

[thegreatestben]

Yeah agreed, I'd go to pickapart, find a filler neck that would fit straight in or near enough with the older style cap (while a newer cap would be nicer they are probably too deep and would hit on the filler flap) & the vent in the neck.



That's an AW11 filler

[NOLAW]

ok got the car back today from the painters so had a chance to have another look at the feul setup, turns out it does have a breatherline, its the line on the left hand side and runs upto the filler neck.....so now im lost again... what else could be causing this

[evil_si]

Is the breather clear? Ie not blocked

[jondee86]

To prevent blowback of fuel out the filler pipe, the vent must enter
the filler neck higher than the end of the filler nozzle. That is to say,
the rising fuel must hit the end of the nozzle before it covers the
end of the vent pipe. The attached pic shows how...



http://www.agcoauto.com/content/news/p2_articleid/242

Cheers... jondee86

[NOLAW]

Cheers guys, I think I can see the problem from the above picture, not exactly sure how I'm gonna go about it as by the looks of the diagram the breather needs to be higher than the filler on the tank, the other option is just getting rid of the filler neck altogether and filling it from the boot untill I come up with a solution.. Anyone know the law on this?

[d1 mule]

Id be waaaaaay more worried about fuel on thr primer than getting on the paint.......

[jondee86]

... by the looks of the diagram the breather needs to be higher
than the filler on the tank.

This ^^^ is not the issue. Both filler and vent can terminate flush
with the top of the tank. When the tank is full, petrol will back up
the filler tube and the vent tube at roughly the same height.

Then this becomes the determining factor...

To prevent blowback of fuel out the filler pipe, the vent must enter
the filler neck higher than the end of the filler nozzle. That is to say,
the rising fuel must hit the end of the nozzle before it covers the
end of the vent pipe. The attached pic shows how...

If you want another option; take the vent tube up high and then
do a U-turn and take it down to vent out thru a hole in the floor.
That's how it was done in the old days

Cheers... jondee86

[NOLAW]

Cheers jondee86, I see what your saying now, ill have another look at the end of the week when I'm home and have a look at where the breather is on the filler neck, I'm pretty sure it's below where the nozzle ends when filling up so this could well be the issue… ill keep you guys updated on how I get on