1957 Fuel leak at fuel filler neck and tank

57txtbird
Last seen
Joined
Dec 22, 2022
Thunderbird Year
1957
Hey all newbie here with a 57 312 D code, I have searched but if I missed please share the link. Recently filled up full with fuel and parked in the garage after. Noticed a strong fuel smell and started inspecting, found the neck was wet at the connection to the tank. Looks like it’s rolling back and eating up the under coating as well. I am wondering is this common and fixable and is the neck or the tank the problem. Or both possibly. All help is appreciated as I try and keep the bird alive. Thanks 282ED8C9-31B8-4CBB-AAC8-71EFD8452E0C.jpeg
 

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There is a rubber O ring that goes on the filler neck. Could be bad. The filler neck just pulls out of the tank. O rings are available.

Make sure the fuel is not from filling the tank (spillage) before trying to replace the O ring.
 
There is a rubber O ring that goes on the filler neck. Could be bad. The filler neck just pulls out of the tank. O rings are available.

Make sure the fuel is not from filling the tank (spillage) before trying to replace the O ring.
Awesome, that makes perfect sense. I will definitely do some further investigating first but I have a feeling you nailed it.
 
I had this happen to me this last summer. I filled up with fuel and parked in the garage. We had a couple really hot days and going into the garage I smelt fuel. I took the filler cap off and the fuel was all the way to the top and was leaking out of the vent hole in the filler cap. Just maybe your car was overfilled? Maybe your car is low in the back and the fuel is leaking out of the filler cap vent. You said that you just filled up.
 
I had this happen to me this last summer. I filled up with fuel and parked in the garage. We had a couple really hot days and going into the garage I smelt fuel. I took the filler cap off and the fuel was all the way to the top and was leaking out of the vent hole in the filler cap. Just maybe your car was overfilled? Maybe your car is low in the back and the fuel is leaking out of the filler cap vent. You said that you just filled up.
I already replaced the seal and it seems to be fine now (one that came out was worn out and flat) but I noticed the angle of the filler neck was bad and determined the tank is to high. After some research I found there is supposed to be 12 pads between the tank and trunk floor. My suspicion is that they are missing I have ordered them and will lower the tank to see if they are in fact there and if not will add then see if the fill neck angle is better. I did also have a sneaking suspicion about it being over filled. I’m thinking no more then 3/4 tank from now on, incase it is sitting low or something.
 
I already replaced the seal and it seems to be fine now (one that came out was worn out and flat) but I noticed the angle of the filler neck was bad and determined the tank is to high. After some research I found there is supposed to be 12 pads between the tank and trunk floor. My suspicion is that they are missing I have ordered them and will lower the tank to see if they are in fact there and if not will add then see if the fill neck angle is better. I did also have a sneaking suspicion about it being over filled. I’m thinking no more then 3/4 tank from now on, incase it is sitting low or something.
The only thing I can ad is to make sure you lube up the gasket well. I hadn't filled my tank for a long time and discovered a leak at the fuel sensor. The gasket crimped when I installed it many years ago. I installed it dry and it didn't seat properly. The '57 has an easy access cover in the trunk so it was a quick repair.
 
Hey all newbie here with a 57 312 D code, I have searched but if I missed please share the link. Recently filled up full with fuel and parked in the garage after. Noticed a strong fuel smell and started inspecting, found the neck was wet at the connection to the tank. Looks like it’s rolling back and eating up the under coating as well. I am wondering is this common and fixable and is the neck or the tank the problem. Or both possibly. All help is appreciated as I try and keep the bird alive. Thanks View attachment 25712I used to take care of a 56 and a 57 t-bird. A few yrs back the 56 I was riding in just quit running. I looked at the gas filter bowl and it was full of black rubber. The ethanol in the gas literally ate the old style rubber and sent it through the system! I ended up having to boil out the gas tank and replaced the rubber tank hose. Also, on the 57, I noticed a high gas smell when checking the oil level. Apparently, the gas ate the diaphragm in the fuel pump that allowed gas into the engine. I rebuilt the fuel pump and that took care of the problem. It sure cleaned out any sludge in the upper end!
 
The fuel tank is leaking where the filler pipe enters the tank. This happened before and I replaced the O-ring on the filler pipe. Its only been a few years since I previously replaced the O-ring. I have only used premium non-ethanol gas in it, so don’t think alcohol ate the O-ring. I suspect vibration loosened it up. I’m looking for a more permanent solution. I’m thinking one possibility might be to remove the tank and have the filler pipe welded directly to the tank. I believe I can mark the filler pipe location so that it would be correctly oriented for re-installation. If someone has a different permanent solution, it would be greatly appreciated.
Drip at Filler Tube.jpg
 
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I had the same problem putting a new tank in my 57 E. The new O ring was round and kept rolling up the filler neck instead of seating in the groove in the tank opening. I looked at the old one and it was flat. I lightly ground a flat surface on the new O ring and it slid right into place and hasn't leaked for years.
 

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