C1 cockpit gas odor!

[Don Izzo]

I have noticed a very strong odor of gas in the cockpit of my 60. I just finished a frame off with a new repro gas tank with the internal baffle installed and all new fuel lines. The vent is connected and the gas filler neck and hose are new and in place with the clamps tight. The gas filler cap is old and I have noticed that unlike my 68 their is no rubber seal under the cap. Is this correct, any ideas why the gas odor is so strong. I seem to remember back in the summer of 69 that my 62 had a similar problem. Is this just a problem I will have to live with? My brother says he doesn't have this problem with his 58 though he never puts more than 10 bucks worth of fuel in the tank.
Don

[Chuck R.]

Re: C1 cockpit gas odor!

I'm no C-1 expert, but I can't believe that the gas cap wouldn't have a gasket of some sort.

Sometimes, gaskets dry out and then when your not looking fall out and get booted (been there done that )

Just wondering in all the hub bub of changing things out it might have accidentally disappeared.

If all lines appear tight and you have no leakage around the carb, that's the place I'd start.

Chuck

[Terry D.]

Re: C1 cockpit gas odor!

I had same problem and it was the the rubber between the tank and fill tube. Got it tight and everything was fine. As for gas cap I believe they were non-vented so I believe they should have a gasket, mine does.
Terry

[Pete Ruegg]

fuel smell

mine too Don. My cap's gasket on my '62 would'nt seal properly because it was not wide enough. I also made the mistake of putting a vented cap on and it also leaked. I made another gasket that touched the inner locking section and the outer ring too. No more gas smell no matter how full the tank and how tight the turns. You can get gasket material at pritty much any auto parts store. Good luck, Pete

[Joe L.]

Re: C1 cockpit gas odor!

Don----

The fuel cap used for 1968 used a rubber gasket. However, I believe that the 53-62 caps used a fiber-type gasket (i.e. like thin cardboard). If that gasket is still present, it may need replacement. If it's not present, then it DEFINITELY needs replacement. I'd recommend making a replacement from a thin sheet of buna-N or neoprene gasket material.

[Jack H.]

Joe's right, as usual!

Original gas caps from this era were non-vented (venting mechanism moved from the cap to the tank in early '57. The cap's sub-assy components are riveted together as a 'sandwich' with two of the assy's being important to sealing.

One is a brass flex plate that forms the interference fit of the cap to the filler neck. Atop that flex plate is/was a paper/fiber gasket. If the cap's an original from the era, odds are REAL GOOD the gasket has deteriorated and the integrity of the cap's seal isn't all that solid any more.

You can cut gasket material (concentric circles) and make a slit (form a close C-shape) to lay the new gasket onto the brass flex plate as a stop gap (savvy judges will look closely at the gasket to see if they can detect a 'cut' or gasket repair/replacement) or you can take the other routes.... (1) install a replacment gas cap (either repro or generic) and take the associate judging deduction(s). (2) figure out a method to remove the original cap's rivet and properly 'restore' your cap (it's TOUGH but it CAN be done) properly.

I'd really look at the other sources of gas odor others have mentioned before concentrating on the gas cap's integral gasket though if the odor is really strong! I'd also NOT overlook the carb and forward fuel line fittings as the source of odor either. Carbs DID have fuel bowl vent stacks to allow outgas/pressure of fuel in the carb's bowl(s) during engine shutdown/thermal soak and some residual odor is just part of the 'beast' with classic cars....

[John H.]

Re: Joe's right, as usual!

None of the old caps will seal worth a damn with the aged paper/fiber gasket; buy a new non-vented replacement cap to drive with and save the ancient cap only for judging.

The fuel odor is even worse (especially if you have a leaky cap) if the drain hose is missing from the nipple in the bottom of the fuel filler door cavity (and 90%+ are); that nipple has a drain hose that goes straight down and exits through a hole in the underbody with a rubber grommet. If the drain hose is gone, any spillage/leakage from the cap drains through the nipple and then dribbles on the inside of the underbody instead, causing a big-time raw fuel odor in the cockpit.

[john pickens]

Re: Joe's right, as usual!

John how does one access that nipple and evaluate if the hose is missing?

[Doug Flaten]

Re: Joe's right, as usual!

Underneath the car there is a hole (1' or more dia?) below the fuel door. This hole should have a hose extending out of it. Shining a light up in the floorboard hole and looking down from the fuel door drain hole, you can determine if no hose is present if you see any light.

To access the drain nipple, you need to remove the gas tank cover panel and you can see if the hose is present, broken or mis-routed. It is likely to have weathered and broken off. It can be replaced without pulling the tank if you have small hands or do not mind bloodying up your hands.

It has been years, but I think you can also pull the seat to see the hose routing down to the floor, but I don't think you could access the nipple from the cockpit.

[Wayne P.]

Re: Joe's right, as usual!

I can't believe with all these responses nobody has mentioned the seal on the tank cover as being a possible part of the problem. Removing the seat will do nothing to help see the vent hose!

[Roy B.]

Re: C1 cockpit gas odor!

Place a towel around the filler neck ,drive the vett and make a hard right turn, stop to see if indeed the gas cap let gas spill out.

[Doug Flaten]

Re: Joe's right, as usual!

I don't know what you mean as far as the tank cover sealing anything. It just provides a base for the soft top to fold down onto. I don't believe it was ever intended to be an air tight seal. I guess I'll have to check my AIM to see if there was sealant used. But you do bring up a good point in that no one has mentioned the vent hose. However, he mentions that he replaced the tank vent hose.

[John H.]

Re: Joe's right, as usual!

Yup, sealer was originally used all the way around the fuel tank cover panel flange, and the resulting compartment was ventilated from below through the large holes in the underbody below the tank.

[Doug Flaten]

Re: Doug's wrong, as usual!

At least my middle daughter says I'm wrong all the time. Thanks for setting me straight. My car had no sealer, but it is anything but an unmolested car.