Fuel System: Gasoline Smell in Garage when Engine Shut Off

[51StoodyCoupe20]

I have a recently acquired 51 Studebaker Champion Coupe. The car has a six cylinder original engine. The previous owner did quite a restore on the car. One item being an electric fuel pump, which works great....but when I put the car in the garage, I still smell a gasoline odor that lingers. No drips anywhere. I keep my garage door open to make sure that there is air circulation. The only think I noticed is when I open the door to the gas tank, the pipe sits back inside several inches, which I've never seen before. When he delivered it to me two weeks ago, he overfilled the tank with gas and it was dripping for the first day until I burned the excess gas off. The smell makes me nervous. By overfilling, could the extra gas be lingering elsewhere? Any ideas would be appreciated. Thanks.

[RadioRoy]

If the rubber hose that connects the filler pipe to the gas tank is leaking, you will get these symptoms. It's not hard to replace if you get the "official" hose from one of the many Studebaker vendors. If you buy the stiff, universal-fit hose from a general parts store, you will have a devil of a time replacing it. That's what I had to do to two cars before the correct reproduction hoses were made.

You should buy the official shop manual and the body parts catalog and chassis parts catalog. They show pictures of almost everything and give the part numbers. Then, when you patronize the official Studebaker parts vendors, you will get the correct parts. Don't even start with NAPA or Rock auto until you have checked with the Studebaker vendors who know Studebakers and are more likely to know what you need.

http://www.studebakervendors.com/

It sounds like the "restoration" was more cosmetic than it was mechanical.

The funny thing about our hobby is that you can put paint and chrome on a barely running car and it will sell. On the other hand if you have a car that is absolutely top notch operation wise, but looks shabby, no one will buy it.

[nvonada]

Is it a strong smell? Keep in mind it is an open vented fuel system and the carb bowl will evaporate down of over time. I get "wiffs" of gas, especially when I park the hot car in the garage and close the door right away. Before emissions controls nobody cared about evaporative emissions.

[jclary]

Regarding the gas odor, check the fuel line from the tank to the carburetor inlet. Since it has an electric pump installed, there will be several connections/fittings added and probably a gas filter. Depending on the type of pump installed, there may also be a pressure regulator (I'm not certain of this since I have never installed an electric pump on a vintage car). Our carbureted cars do not use much pressure and I have read where some installations use a pressure regulator. The important thing is to be certain that all connections are secure and not weeping fuel.

In addition, there are two other potential problems I can think of where a leak can occur. If the mechanical pump is still plumbed up and gas is flowing through the old pump, a leaking failed diaphragm in the old pump can leak fuel out of the tiny breather hole in the fuel pump housing and also into your oil supply in the engine. Both, not good.

The other potentially overlooked item is where the original steel line has rusted where it runs through the factory clamps attached to the chassis. Before I restored my 1948 Champion, I smelled gasoline around the car but could see no obvious leak. When I removed the factory clamps, I discovered that years of accumulated road grime and water exposure had set up a witch's brew of rust and corrosion. When I pulled off the clamps, what was left of the original fuel line crumbled away. I was stunned to discover that the car had been running with gas flowing through a tunnel of fossilized rust and corrosion.

Our old cars do have certain smells that are part of their charm...but too much raw unspent fuel is not one of them. I hope yours is either just you becoming familiar with it, or a problem you can diagnose and an easy fix.

[51StoodyCoupe20]

Thank you to all for your great feedback. Will definitely look into each suggestion.

[j.byrd]

I have through the years, replaced every single piece of the fuel system on one of our cars, but still get a slight smell of gas at times. Keeps my wife from not having anything to fuss about, ha ! I think some of the vented gas caps are just "doing their job" sometimes.. BUT, be sure and check everything the guys have suggested !

[gjamesk]

Another place to check is the fuel level sender in the top of the tank. There is an access plate in the trunk floor. I had a hard time getting mine sealed properly, especially with a full tank.

[airmanjwt]

I had similar problem. Gas cap wasn't venting properly. Drilled a small hole in it. Even though the cap was new and said to be vented. Fixed.

[altair]

The fuel line has been running for years with a vacuum as mechanical pumps create a vacuum, now the same line is under pressure and now the slightest pin hole will weep and never drip. Get under and inspect the fuel line for any evidence moisture (fuel). My fuel line was full of pin holes but didn't leak the fuel pump just couldn't suck the fuel. If I would have installed an electric pump there would have been fuel every where. I replaced the line, no smell and the mechanical pump works just fine.

[SScopelli]

"...he overfilled the tank with gas and it was dripping for the first day until I burned the excess gas off. "

Did you ever figure out where it was dripping from?

It should not be dripping..

Unless you have an open flame water heater in your garage, the vapor smell is not real an issue, but wet gas dripping from your car to the floor is.

[Georger]

Check to see if the parts book show if the washers for the fuel tank sending unit, going into the tank, require compressible copper sealing washers. And if your unit has them. It might be a good idea to put new ones if so. I think that they are not to be reused. Yes, I have had leaks from that area, and cured the problem.

George Rohrbach

[obermotor]

Are Stude gas caps supposed to be vented? I bought a replacement cap for my '48 Commander, which is not vented. When I open the gas cap I get a big whoosh sound, and occasionally a little gas splashing out. I also now have a problem with a slight drip from the fittings going into the fuel pump when I shut the engine down.. Should I drill a small vent hole, as someone suggested?

[RadioRoy]

The gas cap is supposed to be vented.

More detailed answer in the other thread.