Gas tank vent

Jean-Marc Dugas

PCS Member
There is a constant smell of gas in the garage due to the open vent on the gas tank of my 67 Superior. I was looking a different gas tank vent canisters, but they all have 3 or for ports where tubing can be attached. I assume these are there to return the fumes back to either the carburetor of to the fuel tank.

What do you recommend I use to stop or at least drastically reduce the amount of fuel vapor escaping from the gas tank vent?
 
get a new gas cap. the vent should be just plumed up to the top of the filler neck somewhere just under the cap. but I'll bet a dollar(Canadian of course) to a donut that you have a hole, crack, split, what ever or a broken clamp on the rubber hose. it's a problem with them and you can't get one. of course if yous is one of the few using the stock mount and you fill it under your licence plate as you should then I'm wrong on that and I owe you. but if not you may have to go visit your friendly bend to please you muffler house and have them bend you a steel filler hose. then cut some rings off the rubber hose were it's still good and use them to join it together. or your hoses in the front side of the tank are split. I haven't gotten one of these cars yet I have not replaced the rubber gas lines coming out of the tank to the steel lines going to the engine. they will really stink it up to.
 
I would be skeptical that it is the gas tank vent that is the problem, but more likely a rubber hose that is old and cracked that is causing this issue. I have also seen where a carburetor is leaking gas onto the intake manifold causing this type of problem. I suggest that while you have the rear floor out, you replace the rubber gas line from the tank to the metal gas line in both the rear and the front, where it connects to the fuel pump. You also might have a return line from the pump to the tank that has some rubber connections in it. The most important thing to do is to verify the integrity of the system first, before making modifications that might mask the problem, but not resolve it. I also believe that there is a vapor canister in the front left inner panel area that collects these vapors and returns them to the tank and the carburetor where they are burned during normal combustion. If your car does have this type of filter canister, it should have a replaceable carbon filter cartridge. Then also check to see if the tank itself might be leaking slightly. You shouldn't be getting raw gasoline fumes, so determining where they are originating from is priority 1.
 
Here is the vent that I am talking about. You can see it in this picture on the left side of the filler tube. There must be something that attaches to it to prevent the fumes to leak out

picture.php
 
that's the wrong gas cap. it's a ford one. I would say that's were your fumes are coming from. it's not sealing. the vent hole is not big enough for you to get that much out of. should be only a pin hole to let the tank draw air.
 
This is what the vent is supposed to look like according to the FSM. You are missing a lot of parts. They are the same for 1967 & 1968. The loop is designed to direct most of the fumes back to the tank. The amount of fumes when the car is in the garage should be so minimal that you shouldn't be able to detect them.

 
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