I have a 1969 Cutlass.

I bought a repro non-vented gas cap.

Shorty the ethanol gas destroyed the rubber seal inside the gas cap.

Tried some gasket material but does not have enough "cush" to seal.


Does anyone know of a flat O-Ring , rubber? neroprene, or ??? type of material??? brand name and part??? that can hold up to the ethanol gas, and have enough thickness, and "cush" to seal it???

Thoughts???

 

That is weird. My car has the factory original cap and it hasn't had any issues with fuel causing deterioration. I guess that means the seal on the originals is made of a different material than your aftermarket one.

Did you buy the gas cap from an auto parts store or from a repro parts seller? I would expect an auto parts store cap to be tested against today's fuel blends.

 

Got it from Year One, even if they offer to replace it, I would not trust it. The rubber gasket just melted... Looking for a replacement that will hold up long term..

 

Go to O'Reilly's . Ask for a Stant #10646 gas cap
Problem solved .

 

Agreed. My understanding is the real aftermarket (and not the restoration market) has to manufacture parts that met OEM standards.

 

If you are married to the Year None cap, buy the Stant and reuse that gasket.

 

not able to locate an original cap? I have several, including some old stant replacements.

 

Here is what I did:

1. The Stant fuel cap identified earlier in this thread is for a wagon. Stant Fuel Cap #10632 is correct for 1969 Cutlass non-wagons like a 2 Door hardtop.

2. I bought Stant 10632 from Pepboys locally for $4.08 including tax.

3. Drilled out center rivet and removed the seal.

4. To make sure, I got some gasoline and put it into a baby food jar, and put the stant seal submerged in the gasoline over night. Next day, I took it out. I tried to fit it into the stant cap body and the diameter grew by maybe a 1/32" at the most, and the thickness I could not tell very much swelling. AT least it did not turn into a paste like the repro seal did.

5. I cut the inside of the seal so it would just fit the inside of the repro gas cap with correct premium fuel markings.

6. Did a slosh quick acceleration test with a full gas tank, and it seems to be holding the gasoline in now. Time will tell but so far so good.

Thanks for the help folks!!

Fred