The Studeblogger

Monday, February 20, 2012

Lark Deodorant: or, how to get rid of that fuel smell

If you own an old car, it's virtually guaranteed that you will spend time, effort and money trying to track down some problem that should be easy to fix, but which somehow eludes you in the same way in which common sense eludes politicians. This is the story of one such quest - now solved!

Almost since the first day I've owned Barney, there's been the smell of gasoline in the passenger compartment. I don't mean a little whiff - I mean "Hello sir, can I fill 'er up?"-level odor. It was bad enough to require driving with the windows open and vent wings, too, in order to keep the air clear. In chasing this problem, I'd been systematic - replacing the two soft sections of fuel line between the tank and carb, replacing every gasket, hose and tube between the filler neck and the tank inlet (see this post for details), and checking the seal for the fuel gauge sending level for leaks. Nothing worked... it smelled as strong as ever.

Finally, I got a break. I was browsing through Barney's Chassis Parts Manual last weekend (yeah, I read parts manuals for relaxation... ya wanna make something of it?), and noticed something I'd never seen before in the parts diagram for the '62-'63 fuel tank: a UFO (Unidentified Fixable Object).

Look at the diagram above. See the long, bendy tube coming off the filler neck and running to the left? That's the fuel tank vent tube. Studebaker used an non-venting gas cap on later Larks, so this tube was used as a fuel tank vent. It clips to the rear valence panel inside the trunk, wraps around the left taillight assembly, and finally exits through the trunk floor. Well, see the itty bitty part circled in red on the diagram? That's a grommet. It's purpose is to go on the end of the vent tube and seal its exit through the floor pan.

I had never, ever seen this part callout before! And of course, the original one was long gone, so there was no visual evidence that anything was supposed to be there when I inspected the trunk.

So I went down to my local Ace hardware and got an appropriate-sized grommet from the bins (1/4" I.D., 3/8" O.D.), slid it over the end of the vent tube and pressed it into place in the floor.

Woo hoo! That did the job. After a week, I went out and opened up the car at noon - typically when the smell was strongest, after having sat for a while in the sun. No smell! I drove the car around for about 2 hours that afternoon, just to make sure, and the problem is gone.

So, big thanks to a .45-cent part for making my car pleasant to drive again :)

While I was at it, I fixed one more fuel-related problem. A few weeks back, I moved the car onto the street and parked it nose-up (I live on a pretty steep hill). When I came back, a wet spot under the back bumper and a slow, steady drip told the tale: the fuel cap seal was about as loose as a sailor on Friday night.

The factory fuel cap uses a partial-face seal. In the photo at right, you can see it just around the center stamping - that dark brown circle. This is a fiber gasket attached to a steel backing ring; it's only as big as the end of the fuel filler itself and seals to the rolled edge of the filler pipe. I guess that after 49 years, this seal has gotten a bit softer than it was, originally.

The fix for this is actually pretty easy: just add more gasket material. I went down to my neighborhood NAPA and got a roll of 3/32 Fel-Pro cork gasket material. I used aluminum foil to trace the size the gasket needed to be, then cut a circle out of the cork and slipped it around the center of the cap.

Now the cap fits nice and snug, and there's no way any gas is getting past that seal. It ought to help with my fuel economy, too, since the gas formerly used to lubricate the asphalt will now be going into the carb!

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  • Great post. This gives me the idea to fix mine a bit. I pulled the cap off the Commander the night I bought it and noticed that the seal looked a bit worn. I can grab some cork material out of our scrap pile here at work to give me that extra little bit of seal. I am pretty sure we have some mil-spec 3/32" back there.

    By Blogger Sean Reddy, at 12:40 PM  

  • thanks so much for the diagram. Awesome blogger, I just started mine, yours is the bomb.

    By Blogger Francesca Steele, at 10:21 AM  

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