Hi all,
Having a problem with the gas cap on my 74. The gas cap is almost new and in really good shape. However, I must have gone through 3 or 4 gas cap gaskets in a couple of months.
I have been using rubber gaskets that I sourced from a vendor here in the world.
The rubber gasket appears to be the correct size, but after removing and reinstalling the gas cap a few times it bunches up and stretches and gets all messed up. A couple of times it ripped and once almost fell inside the gas tank while removing the gas cap.
I think that the original gasket was made of cork material.
Is the rubber gasket the problem? Should I make or by a cork gasket? or is the spring action inside the gas cap maybe too strong?
Anybody else having this issue?
Thanks,
Bill.

.....Did you talk to the Vendor?

Rather not go there.

Bill,

The original gaskets as I recall were a stiffer pinkish/reddish rubber material &/or in cork because of the compression & torque problems which you've been experiencing. So a soft & pliable silicone or other soft rubber would do as you say - it's just the wrong material for the application.

I'd try to see if you can find a same size gasket which is that hard rubber (or cork) & try that. If you find one oversized on outside diameter &/or undersized on the inner diameter, then you can cut them to size if you have a patter gasket to go from.

Good Luck!
Tom
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Hi Tom T,
Thanks for the information. I was thinking of going to one of the auto stores and buy some cork gasket material and make my own.
Bill.

Let us know what solution you come up with. I am having similar issues with a replacement gasket - probably from the same source as you!

- Tony

Maybe a little lube on the gasket and fuel filler face. Let it slide instead of catch.
I used my ‘71 as a semi daily driver for the past couple of years and no issues with replacement rubber gaskets.

Mark's replacement gasket is a good one, but the real problem is that the reproduction gas caps clip on too tight for the cork gasket, and even Mark's. 356 Devotion makes the cap and they are investigating recasting so it clips on with less pressure If you compare used factory with the reproduction you can see the difference

The gasket attaches to a floating piece that should rotate. So when you lock the cap the gasket should stay stuck to the filler. DR914s explanation makes sense.

I just hand cut one our of 1/16" thick Neoprene. Works fine an gas doesn't hurt it.

Dave

The factory caps make it very difficult to install a factory like seal. Its a fiberous "paper" gasket.
This is why we made a rubber version.
We were able to determine that there was a mixup on the material and we had got the organic rubber used on some of these. Fortunately we have been able to identify when this occurred and will be sending out new gaskets ro all affected by the recall on these.

Our apologies, yo should see these showing up next week.
Sincerely
Mark Whitesell

Maybe this cork-rubber stuff could work? Says "Oil, Coolant, Gasoline".
1/16" https://www.autozone.com/sealants-glues-adh...sheet/67679_0_0
1/8" https://www.autozone.com/sealants-glues-adh...equestid=577100

We stamp ours, and can make from any material. The reason we chose rubber was the prongs on the cap can't be stretched over without breaking the gasket. If you find a better material let me know.

I think the original gasket on my -6 was made of leather. I did replace it with Mikey’s in my original cap and it does seem to work well and not bunch up in the original cap.

Hi guys I have an update on the gas cap gasket problem.
I purchase some gasket material from Auto Zone that was recommended by NeunEinVier on his post.
Cut the gasket and installed it on the cap. Removed the cap and put it back on several times with no issues. Let's see if it lasts.
By the way, my cap is an original part; not aftermarket.
Thank you all for the help.
Bill.

Awesome did you use the 1/16" or 1/8" thickness?

Will you be making cork versions?

Hi NeunEinVier,
I used the 1/16 material. I compared it to the original gasket material that I had from the gas cap, and it was very close.
The real test will be when I drive a bit with full tank and none of the fuel spills out during hard turns

We have sourced a slightly thicker gasket material that is made specifically for gas. Its more expensive but have tested it and fit is good.
Will be recalling all from the last 6 months and sending out.
Mark