gas fumes

[Navydiver]

Hey everyone. I just got done restoring my 1973 SB and it has a strong gasoline smell when I fill up the tank. I have taken off the emmisions canister and redid the hoses for the gas tank so they just loop back to the tank. Does anyone have any suggestions? I guess my next step is to change all the hoses out for brand new ones. I usually come home from work smelling of gasoline and I would like to put a stop to that. Any help would be great. Thanks!
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<-------My Super Beetle is finally done!!!!!!

[79SuperVert]

I would not loop it back to the gas tank, because there has to be some pressure relief. If there isn't any, the pressure is going to push gas fumes out wherever there is a space along the hose joints. I would let one hose from the overflow container drain down to the ground. Mine goes through a hole in the trunk floor and comes out near the brake master cylinder. Just make sure that some point in this hose's routing it is the highest point in the fuel system, to make sure you don't siphon the gas out inadvertently.

Oh, and changing the hoses is a good idea anyway. Prime candidate would be the big fuel filler hose.

[jhicken]

Have ya checked yer gas cap? If it doesn't have the little rubber seal on it, or if it's cracked, you'll get fumes coming form there.

jeffrey

[skidfive]

i also just completed restoring my 73 super beetle from a frame. to illiminate gas smells, first i took teh purifying BS thing out from under the front left fender and all of those tubes also, i then took out the other reuseing purifying long like 2 foot long plast thing above the gas tank and vacum sealed those openings. ALSO, if you have a working gas gauge, dont fill your gas tank up over 3 quarters. becasue if you go arounda turn to fast the gas will go back up through were tha gas cap is leaking the smell. that is the main reason to take the 2 foot thing off the top of the gas tank (purifying thing) because the gas will get stuck up there if you go around a corner to fast, it will smell.

[Bruce]

That two foot long "purifying thing" is the expansion chamber. There is absolutely no reason to remove it, and doing so will create the problems you think you are solving. Its purpose is to provide space for the fuel/vapours to expand into when you fill your tank with cold fuel from the underground tanks at the gas station, then immediately park it in the hot sun. If you don't have this expansion chamber, the pressure in the tank will rise to the point that it will eventually find a way out one of the hose connections.
Your tank must be vented, and the factory vented it from that plastic expansion chamber above the wiper motor.

What the he!! does a working gas guage have to do with causing a leak? So if your guage doesn't work its ok to completely fill the tank?????

[79SuperVert]

No, Bruce, I think skidfive meant that having a working gas gauge will help you determine when you have filled it up 3/4 and no more...

But I agree with you that the "two foot long purifying thing" needs to stay there or else gas fumes will be worse than ever.

Gee, I wonder what other "BS things" skidfive removed when he restored his car...

[Navydiver]

Well let me tell you what I did. I'm not sure if this is right but it helped a little. I took out the expansion chamber out. I looped the fuel line on the drivers side of the gas tank. On the passenger side where there is a small line comming off the top side of the gas tank I hooked that into the line that would have went to the charcoal canister under the right rear wheel well. The fuel line coming off the bottom side of the fuel tank on the passenger side has been totally blocked. Now I don't know if this is right or if I should change it, but it took a majority of the gas fumes away. Now that I've read what Bruce has said, I may hook everything back up with brand new hoses. But here's my problwm. I do not have a charcoal canister in the back. Somewhere inder the passenger side the hard line leading to it ends. This may very well be causing my problem. Should I reroute the fuel line from the expansion chamber somewhere else? Or would it be good to find a new charcoal canister and hook everything back up like stock? Let me know guys. I have an office job and I can't be going to work smelling like gasoline. Thanks!
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<-------My Super Beetle is finally done!!!!!!

[VeeDub Joe]

i have a 72 super and had the same problem, shake your gas cap... does it rattel? mine did, there is a check ball in there, it shouldnt be able to move freely and rattle. when driving and mostly when i hung a right turn at speed the was a heavy smell of gas, i went to napa auto bought a 8 dollar gas cap and it was fixed

o yeah..... when i bought my car the gas lines were routed back into the tank, i thought this looked weird but didnt know it was incorect.


joe
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imports cry when they rev and you bust a weelie!

[79SuperVert]

Looking at the car from the front: Expansion tank on mine is mounted below the windshield and has four outlets, two on either side. Top left outlet has a hose that runs over the top of the expansion tank, down the right side through the floor and ends hanging down near the MC (this is the hose that should have run to the charcoal canister). Bottom left outlet has a hose that runs to the fuel filler hose to catch fumes from there. Top right hose runs into one of the outlets on upper right side of fuel tank. Bottom right hose loops back into the other outlet on right side of fuel tank.

My charcoal canister is inside the right rear fender (looking forwards). The line that was supposed to run up to the expansion tank is cut and non-functional.

[veedo]

[I've seen gas tanks expand like balloons and collapse like pancakes without the pure thingy.quote="Bruce"]That two foot long "purifying thing" is the expansion chamber. There is absolutely no reason to remove it, and doing so will create the problems you think you are solving. Its purpose is to provide space for the fuel/vapours to expand into when you fill your tank with cold fuel from the underground tanks at the gas station, then immediately park it in the hot sun. If you don't have this expansion chamber, the pressure in the tank will rise to the point that it will eventually find a way out one of the hose connections.
Your tank must be vented, and the factory vented it from that plastic expansion chamber above the wiper motor.

What the he!! does a working gas guage have to do with causing a leak? So if your guage doesn't work its ok to completely fill the tank?????[/quote]
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air cooled first,water second-they both need more to go fast. Let them breathe and breed.
The more the better.

[veedo]

[79SuperVert]

Without the canister you'll still get some smells but it won't be as bad as it is now, because if you vent it right the excess will drip down to the ground by the front wheels and won't stink up the trunk and then the inside of the passenger compartment. The point is to vent to the outside air.

[79SuperVert]

Without the canister you'll still get some smells but it won't be as bad as it is now, because if you vent it right the excess will drip down to the ground by the front wheels and won't stink up the trunk and then the inside of the passenger compartment. The point is to vent to the outside air.

[79SuperVert]

Without the canister you'll still get some smells but it won't be as bad as it is now, because if you vent it right the excess will drip down to the ground by the front wheels and won't stink up the trunk and then the inside of the passenger compartment. The point is to vent to the outside air.

[Bookwus]

Hiya Navy,

I've been lurking through this thread for a little while now. Lots of interesting (and some dead wrong) opinions to be seen here. I think it's time for me to chip in.

I have done a lot of work with the M26 emissions system VW started installing in 1970 USA production vehicles. The objective of the system is to trap loose hydrocarbons from the gas tank and route them to the carburetor for burning. This is NOT a passive system as many seem to think. Even so. it has no effect on the available horsepower whatsoever. And EVERY post 1969 vehicle I have worked on in which the owner complained of a "gassy smell" had the M26 system compromised in some fashion.

This system actively works to scavenge the hydrocarbons which make for that gassy smell. To disable it simply makes no sense. Navy, should you need more info about a complete system restoration (easily done for under $75 and probably way less if you have most of the parts) zap me an e-mail. I'll be only too happy to get you on the right track and smelling like something other than gasoline.

Mike

1970 Bus - The Ruptured Duck

[Bookwus]

Hiya Navy,

I've been lurking through this thread for a little while now. Lots of interesting (and some dead wrong) opinions to be seen here. I think it's time for me to chip in.

I have done a lot of work with the M26 emissions system VW started installing in 1970 USA production vehicles. The objective of the system is to trap loose hydrocarbons from the gas tank and route them to the carburetor for burning. This is NOT a passive system as many seem to think. Even so. it has no effect on the available horsepower whatsoever. And EVERY post 1969 vehicle I have worked on in which the owner complained of a "gassy smell" had the M26 system compromised in some fashion.

This system actively works to scavenge the hydrocarbons which make for that gassy smell. To disable it simply makes no sense. Navy, should you need more info about a complete system restoration (easily done for under $75 and probably way less if you have most of the parts) zap me an e-mail. I'll be only too happy to get you on the right track and smelling like something other than gasoline.

Mike

1970 Bus - The Ruptured Duck

[av8rdan]

Hi - just bought a '71 Super which needs a great deal of help. It was more mistreated upon closer examination - of course - than I thought when I bought it. Poor thing was painted pink, including under the hood, and the first thing I'm tackling is a new wiring harness. But the fumes - oh my. The collector box you all describe just is not there, ditto the carbon canister. I've temporarily rerouted the hoses to more or less seal the system but that can't be a good idea. Do you know if anyone sells the collector box that oughta be in there but isn't?
Thanks,
Dan

[79SuperVert]

My favorite places to look for repro parts like that are wolfsburgwest.com and cip1.com

[gophercat]

I have a 72 super beetle with a working expansion tank and the carbon filter canister. The only time I get fuel fumes in the car occurs when the tank is overfilled. The filler neck is intended to be a filler neck- not the tank itself. A properly filled tank goes to the top of the tank and not higher. Where the pump cuts off, if you go by that, is beyond where the system is actually supposed to hold fuel. So it kind of makes sense that after you drive about 5-10 miles after filling the tank the smell is miraculously gone. With the hard cornering bit- one way you would get the smell there is if the neck is not sealing properly and you actually get small amounts of fuel in the compartment or you have a bad gas cap. The part 2 foot part under the hood is an expansion chamber and that takes in evaporated gas and if it condenses drains it back into the tank and any fumes route to the carbon canister to be collected and circulated into the system as Mike "bookwus" stated. If you take all of that out and seal the system and have a properly working gas cap and filler neck then your tank becomes a vacuum- not good at all. If you took it out and and "sealed" the system and your tank isn't becoming a vacuum- your smell was probably an issue with the seal on your filler neck or gas cap not working properly in the first place.