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gas smell

golfobx

Sr. Member
Joined
Oct 10, 2014
Messages
592
Loc.
Suffolk, Va
I'm wondering if anyone else is having this problem...when parked in my garage it smells terribly of gas...wondering if the gas cap is letting the vapors leak out.

secondarily, would enough vapor leak out after several days to actually drop the level of gas in the tank?

can anyone advise a better cap to seal it up better?

i got a 69 with dual tank

...i installed new tanks, and there are no leaks anywhere, so it has to be coming from the caps
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
Check the floor around your fuel selector valve for gas dripping out of the stem. Mine would need a new o-ring every couple years.
 

Whoaa

Bronco Guru
Joined
Sep 26, 2014
Messages
1,059
Yes.......No


Does the [vented] cap let vapor's escape? Yes.

Yes, of course it does. Along with the vent tubes. Gasoline has massive expansion & contraction depending on temperature. If you sealed up the fuel tank and the entire fuel system bad things would happen.

NO, vapor in a gaseous form doesn't not vent enough to subtantially effect the gas gauge.

You have a LEAK somewhere. And based on your discription that you can smell it, but haven't noticed any leaks yet, tells me that's its probably soaking into something..and/or pooling somewhere so there is open gas vapor's that you're smelling.

In a best case scenario its bothersome because you have a gas smell in your closed up garage. A little worse, and these fumes could make there way into your home if your garage is atttached to your house. And in a worst case scenario these fumes could cause a fire/explosion.
 

DJs74

Bronco Guru
Joined
Apr 1, 2014
Messages
1,135
Mine smells gassy too especially if it's full and usually it's just vapor fumes coming from the vented gas cap. To verify you have no leaks anywhere, you might try putting some cardboard down under it over night from bumper to bumper and just double check and make sure you don't see any "spots" anywhere.

DJs74
 

dave67fd

Contributor
Bronco Guru
Joined
Sep 24, 2010
Messages
2,863
Could you also be smelling maybe gas at the carb? Could be a bad carb to manifold gasket or slight percolation. Not enough to notice a small leak which might also be evaporating. Is it running well?
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,721
All of the above. But DJ's, with yours smelling worse after a fillup, if it's not the hoses at the tank, then I would suspect that the condensing tank behind the driver's left shoulder behind the panel has split a seam.
If your vapor recovery system is still intact, that's the first place I'd look.

For yours golfobx, what they all said holds true. If you have an open-element air filter then just the carburetor's bowls evaporating out of the vents can do that. Which is why they're not smog-legal in CA. Some carbs get away with it better than others, but some will always come out the vents.

If your cap is bad, it will leak.
Your '69 would not have the vapor recovery system (charcoal evap canister), but might have a leak around a filler or sending unit.
If you have two tanks, the most common spots for leaks (other than the caps) are the seams on the plastic aux tank and the fuel stock tank selector valve on the driver's floor, like mentioned.
And of course, any of the hose junctions. If the hoses are old, they can leak in the most remote locations so you can't see the leaks until they get real bad. But they still smell!

Paul
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,975
When looking for leaks, they won't always show up as wet drips. Look for clean streaks. Gasoline is a wonderful cleaner. A leak will leave a clean drool line down from it.

Could be carburetor releasing the vapors as well. I have known people to have a manual switch on the electric fuel pump so they could run the carb dry when they parked it in the garage just so they wouldn't smell it. Got interesting as they knew which house they passed on the way home to turn the pump off at so they could get into the garage and it would run out of gas about 15-20 seconds after they parked it.
 

Texas9902

Full Member
Joined
Jun 14, 2013
Messages
176
Loc.
Dallas (Lakewood)
Second on what everyone else has said, but another factor could be your garage. If it's well sealed and you shut the garage, any little fume smell is going to be magnified overnight. I had the same problem and my rig runs tip-top. However, I have an insulated door and no ventilation. It's not a problem with modern cars for a number of reasons. However, when I park my Bronco, it reminds me of the garages of my youth.
 
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