gas cap issue

Ken Arms

Well-known member
Hi folks, so I have a Drake tank in my 34. The gas cap is original and I put a new cork (hand made) gasket on it, every time I fill up it leaks out, I'm careful to stop pumping too close to the top and the tank even has a flipper to trap the slosh. I tried an after market cap as well with no better luck. Help? Thanks Ken
 
Is it leaking out at the gas cap or is it leaking at the seam? Drake's tanks leak at the seam where the two pieces of the tank join each other. My 35 pickup tank leaks at the seam. I just don't fill it up over halfway.
 
Ken has that new gasket possibly caused some venting issues. I had a simillar problem with my 77 and the little vent hole was plugged with pollen/dirt ect.

As that tank might heat up in this July summer those vapors need a way out. Also check (if built in) the smaller 1/4-3/8 little neck overflow tube for blockage that also helps with venting.
 
There is always a series of stains around my hot rod tank cap, expected and accepted as constantly re-cutting the cork rings, don’t care anymore. Now it’s called patina, so save me work don’t care anymore
 
Some things to consider and check.


Do you have a vented cap? If so, its going to leak out the vent when the tank is full and gas sloshes or the car is at the wrong angle. Original 1934's had a non-vented cap, the vent was at the original fuel pickup/fuel gauge sender location. Before you switch to a non-vented cap make sure the tank is vented, Suction from a fuel pump has been known to collapse and crumple a tank.
 
Karl is correct.In fact 32-35 had a non vented cap.36-40 was vented.Here are pic of the back side of those caps.The left is 32-35 and right 36-40 that shows the vent hole.
 

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I made a bib out of an old fender cover. Cut a hole for the fill tube and use the gas cap to hold it on. You can get creative with the shape
 
Ken, I had a lot of trouble with gas leaking from the cap on my '34. I tried everything; different caps, cork gaskets, rubber gaskets- nothing worked. Then I bought a cap from Tanks Inc. about 3 years ago and it hasn't leaked since!
Their # is; 877 596 3842. (Make sure you ask for a non-vented cap). Hope this helps. Good luck, Doug.
 
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