Fuel Smell in Garage

[makamer]

We have an issue with our 72 C10. After we drive it and then park it in the garage, it eventually fills the garage with gas fumes. I can't find a leak anywhere.

I rebuilt the carb thinking that may be the problem but found no leaks and the gas smell remains. I can even let it sit for days in the garage and the smell comes and goes.

Anyone have any thoughts on what it could be?

[Stevo427]

Stock behind the cab fuel tank? Mines always done it.

[makamer]

Yes. the funny thing is that the cab doesn't really smell. Just seems to be in the garage.

[Stevo427]

Well for me it usually comes out from where the gas cap is. I even have a locking gas cap and sometimes while sitting at a stoplight I'll get a nice whiff of gas.

[Dunenutt]

Expansion of fuel in the tank exiting out the vented cap. Fuel in the carb bowls will fume for a while after driving, but that usually stops when it cools down.

[Gumby]

leave the door open for 20-30 mins or install some roof vents so it can breath in there.

[makamer]

I don't smell anything in the cab so I don't think that is the problem.

[Gumby]

im talking about the garage, leave th door open so it can cool down and any gas vapors leave, or put vents in the garage roof so they can leave that way.

a garage so sealed up that fumes can build in it, isn't good to begin with.

[Dunenutt]

Originally Posted by Gumby

im talking about the garage, leave th door open so it can cool down and any gas vapors leave, or put vents in the garage roof so they can leave that way.

a garage so sealed up that fumes can build in it, isn't good to begin with.

Or vents down low where the fumes collect.

[makamer]

I can leave the garage open and it airs out but after 1/2 day or so it is back. I'd rather fix the problem with the truck if I can.

[storm9c1]

Wait, '72 -- does that have the charcoal canister system? If so, can you smell gas around the area where the canister is? Or can you smell it around the cap area (even if you don't smell it in the cab)? The fumes are coming from somewhere. You need to find from where. Gas is really funny, if you garage is hot, or your truck was sitting in the sun, gasoline really starts to expand and outgas. Those fumes need to go somewhere. Most of the time, the fumes are forced out a bad gas cap or forced out the charcoal canister vent.

[GASoline71]

Is there any fuel puddled on the intake manifold? I have a '72 GMC with a vented cap on the stock behind the seat tank and have no smell of fuel whatsoever. So I really doubt it is the gas tank vent.

The smell of raw fuel can be from leaking fuel lines as well. Check under the truck where the stock lines come off the tank and goes to th steel line that runs along the frame. The stock original rubber linline that connects the tank to the steel line could be rotten. Mine was and it was leaking. I replaced it with a braided steel line. You need a flexable line for this connection. Its only about 4" to 6" long.

Gary
Posted via Mobile Device

[Gumby]

A warm many mile qjet often seeps gas out the body gaskets after a drive. Though doesn't cause a problem u notice.

[GASoline71]

That's a good point too Gumby. The Q-puke on the '79 GMC I had did that exact same thing. But I think the PO said her rebuild his carb.

Gary

[midniteblues]

Be sure too air out the garage good before flippin the lights on.

[LEEVON]

You could have a needle sticking open, the fuel line pressure could bleed into the carb when the truck is off.