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Old 04-18-2008, 10:28 PM
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fuel sending unit leak??

so i am in the beginning stages of restoring my fathers 57 nomad(he passed away last feb ) and i finnaly got it running.
i have just been driving around the block everyday just to get it used to running again( its been stitting around for around 20 years).
today when i was leaving for work i noticed the smell of gasoline and noticed that gas was leaking from the tank( not alot but enough to be a issue).
so after work i lifted the back end up and climbed under, after a few minutes i had realised that there was some rubbery epoxy like substance over the sending unit on the gas tank... and thats were it was leaking from.
so i took off the old rubber stuff cause it was falling off anyways. and drove the car around the block a few more times hopefully getting the gas level lower so it wont leak quite as much.
does this sound like the sending unit gasket seal is bad?
im hoping its not something worse, cause i know that to even remove the tank you need to drop the axel, leaf springs, and suspension and i dont have the resources to do that.
i was hoping that this is a easy fix i can do, it looks possible to remove the sending unit and change the gasket, but has anyone else changed the gasket without removing the gas tank?

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Old 04-21-2008, 09:35 AM
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best to pull it

leaking tanks are dangerous. someone could flip a cigarette and poof your car would be gone. I am not familiar with the 57 but some older cars used paper gaskets and others use a rubber o ring. sometimes undercoating was sprayed on tanks
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Old 04-21-2008, 01:20 PM
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All the aftermarket sending units use a rubber gasket. I think the OEM gasket was some sort of composit material. Sounds like yours may be rubber. This sending unit does not use an "O" ring. It can be changed without removing the tank, provided the fuel level in the tank is below the sending unit. If the screws are rusted in and you break one off, then you will need to drop the tank to repair the broken screw.

First remove the wiring from the unit along with the ground and tape them up. Sparks under your '57 would not be good at this time. Remove the screws, remove the sending unit, and clean the surface of the tank where the gasket goes, then clean the sending unit gasket surface and test fit the new gasket. Coat both sides of the new gasket with Aviation Permatex, available from local auto parts store. Let set for 30 min and slip over the float and up to the sending unit mounting flange, reinstall sending unit. Put a dab of permatex under each screw before installing them for good measure. Don't over-torque the screws because the gasket will squeeze out. Aviation Permatex is fuel resistant, silicon sealers are not.

Since you will have the sending unit out you may as well check it for proper operation with your fuel gauge and calibrate if necessary. If I remember correctly the gasket will only go on one way, otherwise the holes won't line up for the screws.
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Old 04-21-2008, 04:27 PM
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Sounds like someone tried to patch it from the outside rather than replacing the rubber ring. I am fairly certain the 57's used a rubber o-ring.
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