Fuel Vent Leaking Fuel

John Galbreath Jr. · May 7, 2012

On the 38 Special, the fuel vent comes out of the top of the tank on the passenger side. If I fill it up all the way, or if the passenger side is downhill, fuel will come out the vent. A lot of fuel, a steady 1/4" stream. Will something like this fix the issue?

http://www.holley.com/251006ERL.asp

I have heard I could take the vent hose around the top of the tank, then down, but that will not look good.

Cole · May 7, 2012

John my buggy does the same thing and mine is looped. If you try that and it works let me know or if you find another solution.

civicmindedex79 · May 7, 2012

I have this one from RCI on my buggy. It does the same thing. Only seals off when completely upside down. Post up if you find something.

Welderd · May 7, 2012

had several and tried several fixes - never works and always leaks. I did slow it down though.

the thin tanks we use easily build pressure and the vent is the only way out, plug it a little bit with fuel and it will push it out, even if tube runs up around and out. Once the suction is started it won't stop until you uncover the vent.

a second or third vent is the ultimate fix, teeing them together and then running up high and 3 sides and down.

Welderd · May 7, 2012

what looks worse some line running around or your **** on fire!!!

ranger11 · May 7, 2012

I capped off the roll over valve in the tank and put a new one in the fill cap. I havent seen any fuel come out.

http://www.summitracing.com/parts/SUM-220020/

al1tonyota · May 8, 2012

Don't put so much fuel in it is the easiest fix! :****: leave room for the fuel to expand! Mine isn't vented and if I put to much in or the temp changes alot it'll push fuel out around the cap!

John Galbreath Jr. · May 8, 2012

al1tonyota said:
Don't put so much fuel in it is the easiest fix! :****: leave room for the fuel to expand! Mine isn't vented and if I put to much in or the temp changes alot it'll push fuel out around the cap!

That is a good solution, but the tank on the 38 is multi-shaped to fit around the cooler and speaker boxes. So the top 3-4" hold 40% or so of fuel.

Thinking of puting in the part I showed in the first post and running the vent higher than the tank. I can get it about 4" higher than the tank and still be below the hatch. Right now, it comes out of the top of the tank and turns down over the edge and runs down about 18" to the bottom of the buggy.

jtreeves1 · May 8, 2012

we have a bottle that catches it and then it drains back into the tank ... befor we would loose almost 3 gallons of fuel on a hot day from it coming out the vent

JMoore · May 8, 2012

Not sure if this is what your looking for?
http://www.polyperformance.com/shop/Fuel-Cell-Tip-Over-Valve-p-21437.html

InDaShop · May 9, 2012

the problem is those only seal if upsdie down, if on your side they still spew.

There are a few different valves here.
http://www.atlinc.com/pdfs/Racing/2012-ATL-RACING-CATALOG-web%2022.pdf

I think its a combo solution. A good in-tank ball valve at the tank bulkhead or screwed on top. Then the 3 sides and down but with the 3 sides one being as high as possible. And lastly putting a lever valve on your vent so if it is in or going to be in a leaking angle you can close it until/after you get out of that position.

crawlin85cj · May 9, 2012

Mount a rollover vent inline on a near horizontal plane? The natural movement of the rig should allow it to stay open enough to vent?

Probably a terrible idea but it is all I got

TBItoy · May 9, 2012

why not put a charcoal canister system on it?

My toyota doesnt' leak fuel even when upside down. (stock tank and stock CC/vent system)

crawlin85cj · May 9, 2012

Maybe mount a can like this in one rear corner, connect the vent line to the can and route another line from the can to the opposite rear corner? It would have to fill up before the fuel entered the 2nd line. When the tank level dropped below the can level the fuel would flow back into the tank.

InDaShop · May 9, 2012

funny how them speedway cans have spread like wildfire through the offroad community.....

crawlin85cj · May 9, 2012

Its dang near impossible for them to spill, they package easy and they are pretty to boot.

InDaShop · May 9, 2012

I dont think they are up to the task of a fuel vent catch, the tube is straw is 3/16", But it wouldnt look bad mounted up high on the B pillar either though.

My '58 I finished in Aug '06 and promptly drove from Houston to Kansas to Joplin for the HAMB Drags. Two years later I added one to my old buggy and since then they have caught on I guess :dunno:

mrdrinksalil · May 10, 2012

I've had bad luck with those rollover shutoffs. The one I had was an Aluminum AN fitting like the ones posted but uses a steel ball. The one time I needed it, it didn't work. Took it apart and the ball had a small amount of corrosion and was stuck. I now have the vent line run down three complete sides of the tank, no matter which way you lay the rig over there is still a spot in that vent line that is higher than the fuel level. Adding a catch can to my current setup would be best, because you do loose a small amount of fuel when you get the rig back on all 4's.

Neal3000 · May 11, 2012

there's some good info and drawings about fuel cell venting at the bottom of this article-
http://www.billavista.com/tech/Articles/Fuel_Cell/index.html

John Galbreath Jr. · May 11, 2012

Neal3000 said:
there's some good info and drawings about fuel cell venting at the bottom of this article-
http://www.billavista.com/tech/Articles/Fuel_Cell/index.html

Thanks for that, good reading.