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New Black Fuel Tank Gas Cap
Fits 46-71 CJ-2A, 3A, 3B, 5

Part # 640594

New Replacement Fuel Tank Gas Cap in Black

Great reproduction black gas cap for the original under the seat mounted tanks. Non-locking.

Helpful Guides and Illustrations:
Fuel Tank Exploded View

46-49 CJ-2A
49-53 CJ-3A
53-64 CJ-3B
55-71 CJ-5

Part # Price





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My original gas cap seems to have veriacal lines/ridges. Does this one have thesame?

Willys Jeep Parts Tech:
I do believe so but will double check.

Will this cap fit the polypropylene replacement tank for a 1969 CJ5 with a V6?

Willys Jeep Parts Tech:
No it will not.

Can you tell me how this gas cap is vented?

Willys Jeep Parts Tech:
There is a check valve under the cap. You can see it in the images.

Is there a LOCKING GAS CAP that fits the under the seat tank in my 1955 CJ5 ?

Willys Jeep Parts Tech:
Sorry I dont believe a locking one is available.

Another customer asked: Is this cap vented? Yes this is a vented cap. It does have a check valve. My question is what is a check valve? Will it prevent gas dripping out of the fill spout? If not do you how to stop gas dripping out of the fill spout? Thank you

Willys Jeep Parts Tech:
If it is vented it really shouldn't drip out because it is vented.

do you know where i could get a locking gas cap for and under seat tank cj 6 please i appreciate

Willys Jeep Parts Tech:
Sorry, that is not available.

Is this the cap for fit the plastic tank #: MTS-0005 and what tie down straps are needed for tank MTS-0005? will I need an electric fuel pump for this tank?

Willys Jeep Parts Tech:
Yes, the 640594 is for that tank. Your oringal strap or A1472K is the correct strap for it. Thanks!

Will this gas cap work with the plastic reproduction under seat tanks?

Willys Jeep Parts Tech:
As long as your plastic tank takes the original caps it should no problem.

What are the dimensions of this product?

Willys Jeep Parts Tech:
Please email mike@kaiserwillys.com and we can take any exact measurements you need.

About to order a new gas cap; the black gas cap for a '61 CJ5 (Item No. 640594) is vented, correct?

Willys Jeep Parts Tech:
Yes, it is vented. Thanks

My fuel bowl will not stay full, I have a 1968 jeep with F-134 eng and fuel tank mounted under the seat. I have a new fuel tank, new fuel pump, and new fuel line, seems to be vapor locking can a faulty fuel cap cause this?

Willys Jeep Parts Tech:
The fuel bowl typically doesnt fill up all the way. But i would for sure use a vented gas cap.

The ad says the gas cap is chrome but in the photo the cap looks black, so is it chrome or black?

Willys Jeep Parts Tech:
Just a typo. Its black. It will be updated shortly. Thanks!

Can you add any pictures of one installed?

Willys Jeep Parts Tech:
See part number: Z8300 for examples of a summer top. Scroll thru photos

Is the gasket in this cap compatible with gasoline containing alcohol?

Willys Jeep Parts Tech:
Yes, that is correct.

Is this 640594 gas cap vented. I need a non-vented gas cap. I cannot get the fuel to stop leaking when on hill slanting to cap.

Willys Jeep Parts Tech:
908593 is non vented currently.

Is this the correct Gs Cap for a Willys CJ3A 1951 ? Thank you.

Willys Jeep Parts Tech:
Yes, that is correct.

I have a 71 cj5 with the small fill neck, 1.5" will this work for this model? Thanks

Willys Jeep Parts Tech:
If you are an under the seat gas tank this is the proper cap. These do not work for rear mounted tank.

I am needing the gasket that fits this cap. Do you sale them separate? Thanks

Willys Tech:
Sorry you will only find complete gas caps on this vehicle.

54 cj3b will this fit the 3 inch opening on my tank?

Willys Tech:
Yes this is proper for the CJ-3B.

Is this cap vented?

Willys Tech:
Yes this is a vented cap. It does have a check valve.

i have the cap for a 1958 jeep willys cj5. do you sell the Gasket only by itself?

Willys Tech:
I dont have just the gasket. You can make it locally out of paper gasket material.
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