Leaky fuel cap

[Stroker Coupe]

Whenever I fill the fuel tank in my 34 it sloshes out when I go around a corner or up a hill until the fuel level gets down quite a bit. I've replaced the cap and still have the same problem and can't see anything wrong with the filler neck or cap. Is this just a characteristic of 34s or am i missing something? This is very annoying, not to mention dangerous, so any advice would be appreciated. Thanks.

 

[Brian]

Dunno, but I've always had the same problem with my 35. I have now fitted a spring loaded 'flap' into the filler neck in an attempt to stem some of this leakage. And a 35 filler neck is a bit longer than a 34, so I think it's part of the legacy of owning an old Ford. Brian

 

[Lawrie]

I had the same problem on my 33 sedan ,but not on my 34 3w,
I looked at the filler neck but it seemed OK tried another cap ,same.
I took the tank out and put some fuel in and turned it up side down ,the fuel hosed out ,
On closer inspection ,it came out of the cap,which was vented , I got the cap from the 34 ,no leaks,and not vented,so I got another cap from the USA and now have the leak fixed.
Look closely at your cap.
Lawrie

 

[Bruce Lancaster]

Right, '32-35 caps are unvented and need to be so because they are so close to fuel level. The vent on these years is at the gauge sender...that probably leaks like crazy, so don't look under there!
'32-48 caps interchange and most available ones are vented...I think even Ford sold the vented cap to replace the '32-5 ones.
If you have a vented cap that looks good, most types can be unvented with some solder. If it leaks from gasket area replace or shim gasket, study top of pipe for dents or scratches.

 

[JM 35 Sedan]

Whenever I fill the fuel tank in my 34 it sloshes out when I go around a corner or up a hill until the fuel level gets down quite a bit. I've replaced the cap and still have the same problem and can't see anything wrong with the filler neck or cap. Is this just a characteristic of 34s or am i missing something? This is very annoying, not to mention dangerous, so any advice would be appreciated. Thanks.

__________________________________________________________________

Al Casteen, aka Hamtown Al showed us some sort of plastic filler cap that he buys at one of the after market auto chain stores and modifies it so that it will go into the filler neck and then gets permanently trapped in place under the gas cap. During gas fill up the pump nozzle fits through this little plastic filler cap allowing gas to flow in but will close when nozzle is removed. The regular cap is then put in place and wallah no more gas spewing out of filler neck during take off or when making sharp turns. If you send him a PM, I'm sure he will fill you in on exactly where to get this piece and how to modify it to fit into the gas tank neck. JM

 

[33cabriolet]

The cap can't have a vent or it will leak when turning right.the sealing surface of the filler neck has to be flat,if it is not too beatup it can be filed to get it flat,Mine was so damaged that I had to cut it off and braze the sealing surface and turn it down to get it to seal.It gets annoying someone coming up pointing at the filler neck.

 

[Uncle Bob]

__________________________________________________________________

Al Casteen, aka Hamtown Al showed us some sort of plastic filler cap that he buys at one of the after market auto chain stores and modifies it so that it will go into the filler neck and then gets permanently trapped in place under the gas cap. During gas fill up the pump nozzle fits through this little plastic filler cap allowing gas to flow in but will close when nozzle is removed. The regular cap is then put in place and wallah no more gas spewing out of filler neck during take off or when making sharp turns. If you send him a PM, I'm sure he will fill you in on exactly where to get this piece and how to modify it to fit into the gas tank neck. JM

Here's a link to Al's personal website and his article on the cap ; http://www.36fords.com/Gastip.html