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Ken Arms 05-11-2026 07:56 PM

gas cap leak
 

could use some suggestions as to stop my gas cap from spilling when full. I have tried a new gasket on original cap, tried a new cap as well. Car has a new drake tank with a spring loaded flipper. (34 ford). Ken

TJ 05-12-2026 09:32 AM

Re: gas cap leak
 

A regular cap or a locking cap?

19Fordy 05-12-2026 09:35 AM

Re: gas cap leak
 

Can you post photos of the cap you are using?

Also, try a double gasket.

Kube 05-12-2026 09:47 AM

Re: gas cap leak
 

Quote:

Originally Posted by Ken Arms (Post 2451185)
could use some suggestions as to stop my gas cap from spilling when full. I have tried a new gasket on original cap, tried a new cap as well. Car has a new drake tank with a spring loaded flipper. (34 ford). Ken

My guess? Overfilling the tank.
The design of the filler tube is not the greatest and often enough, when the tank is very full, the fuel will get past the gasket.
How about next time you put gasoline in the tank, stop at half or so and see if that cures the issue.

34fordy 05-12-2026 11:29 AM

Re: gas cap leak
 

I thought my improvement was perfect until I looked today. Back to the drawing board. lol

325w 05-12-2026 09:04 PM

Re: gas cap leak
 

I use red rubber from the Ace hardware. Cut to fit. They last for a year are so.

Karl Wescott 05-12-2026 11:11 PM

Re: gas cap leak
 

1933-34 originally used a NON-vented cap which sealed the fill neck opening. Locking gas caps by their nature are vented and will spill fuel. Confusion abounds about the replacement caps in part due to Ford in the "Green Bible" back interchanging the later vented cap to 1932.


The Drake tank should be vented on the top (usually in the pickup tube area). With a non vented cap and a non vented tank and a strong fuel pump you can make a 12 gallon tank into a 2 gallon tank (Our family did it on a '68 Plymouth wagon).


My guess is the wrong cap.

vincent 05-13-2026 04:19 AM

Re: gas cap leak
 

I had a (non - working) lockable cap on my 34, spilling fuel when doing fast right turns with a full tank. I replaced the lock with a container attached to the cap that allows to breath enough but would need several clockwise laps with a full tank before the little container is filled with fuel and will spit through the breathing hole. If anyone is interested I can take a pic.

TJ 05-13-2026 11:22 AM

Re: gas cap leak
 

I've had good luck using the caps from Napa Auto Parts. They are stainless with a rubber gasket. The only drawback is they have a flat spot on the top and you have to remove the decal on the flat spot. Never had one leak.

Ken Arms 05-13-2026 12:50 PM

Re: gas cap leak
 

thanks everyone, I just ordered a new cap from bob drake, its advertised as a vented cap with neoprene gasket and no leaks. I will provide feed back if it works. Ken

The Art Doctor 05-13-2026 01:42 PM

Re: gas cap leak
 

Mine does the same. My tank is new Drake too and needs a vented cap due to a modern sending unit. Been trying to figure out where its coming from and I think it is between the seal and the top flat part of the neck as its slightly wet there when I take the cap off. There is always a small puddle between the slosh valve and the opening so I know the slosh valve is not terribly effective but probably it would be worse if it were not there. The cap is very tight on and off so I can imagine adding more gasket thickness would not help, possibly a fresh one as you are doing would be the trick. I'll wait and see how yours turns out.

34fordy 05-13-2026 02:25 PM

Re: gas cap leak
 

Quote:

Originally Posted by Ken Arms (Post 2451371)
thanks everyone, I just ordered a new cap from bob drake, its advertised as a vented cap with neoprene gasket and no leaks. I will provide feed back if it works. Ken

I didn't have any luck but maybe this is "New and Improved" so be sure to let us know Ken!

petehoovie 05-13-2026 03:12 PM

Re: gas cap leak
 

Quote:

Originally Posted by Ken Arms (Post 2451371)
thanks everyone, I just ordered a new cap from bob drake, its advertised as a vented cap with neoprene gasket and no leaks. I will provide feed back if it works. Ken

https://bobdrake.com/cdn/shop/produc...g?v=1612286276

https://bobdrake.com/cdn/shop/produc...g?v=1772580460

1934 05-14-2026 04:48 AM

Re: gas cap leak
 

I had the problem of leaking gas whenever I filled up. I tried everything, different caps, gaskets, etc. Finally solved the problem with a cap from Tanks Inc. No more leaks!
Doug.

JimG 05-14-2026 03:21 PM

Re: gas cap leak
 

I also got a cap from Tanks for my 34 a few years ago. Doesn't leak no matter how full I fill it.

34fordy 05-14-2026 04:07 PM

Re: gas cap leak
 

Quote:

Originally Posted by JimG (Post 2451524)
I also got a cap from Tanks for my 34 a few years ago. Doesn't leak no matter how full I fill it.

Could you provide the part number please. When I went on their website I didn't see the appropriate part. Possibly you could post a picture?

petehoovie 05-14-2026 06:07 PM

Re: gas cap leak
 

Quote:

Originally Posted by 34fordy (Post 2451546)
Could you provide the part number please. When I went on their website I didn't see the appropriate part. Possibly you could post a picture?

See > https://www.tanksinc.com/index.cfm/p...prod/prd91.htm

Only $15.95
Part # TC-32PV

Description:
1932-48 Ford Chrome Fuel Cap for 2-19/32" Neck- Vented
https://www.tanksinc.com/cartimages/...02002031549450


TC-32 Back Side of Cap - Non Vented
https://www.tanksinc.com/cartimages/...01909301535260


TC-32PV Back side of cap. Pressure vented.
https://www.tanksinc.com/cartimages/...01909301535260


TC Back side of cap. Vacuum relief.
https://www.tanksinc.com/cartimages/...01909301535260

34fordy 05-14-2026 07:51 PM

Re: gas cap leak
 

Thanx Pete. Don't know why I could not find it. Kinda what I figured that it would need a little reed valve or something similar. Really a reasonable price!

34fordy 05-18-2026 06:27 PM

Re: gas cap leak
 

[QUOTE=petehoovie;2451565]See > https://www.tanksinc.com/index.cfm/p...prod/prd91.htm

Only $15.95
Part # TC-32PV


TC-32PV Back side of cap. Pressure vented.
https://www.tanksinc.com/cartimages/...01909301535260

I ordered and received this nice cap today. I put my mouth on the blue (check-valve) and found that I had to lightly suck to open the vent. I am wondering if this negative pressure affects the fuel pump discharge pressure or the pumps ability to bring fuel to the pump. I would think that the pump pressure would not be affected.

The Art Doctor 05-28-2026 10:08 AM

Re: gas cap leak
 

I think that it would be great. I just ordered two, thanks for sharing.


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