fuel tank sender unit question

[busycoupe]

I don't usually fill my gas tank to the tippy-top, but I did yesterday.  Last night I noticed a strong smell of gasoline in the garage.  When I investigated I found that gas was seeping out around the tank sender unit.  Actually, it appeared to be seeping out around several of the screws that hold the unit in.  When I took out the screws I dicovered that they had thin metal washers under them.  A few of the washers were cracked.  The metal is very soft, almost like lead.  Not having any of these washers, I replaced the cracked ones with washers I cut from cardboard.  Here is my question:  Are the soft metal washers supposed to be there?  Is it OK to replace them with fiber washers?  The gasket between the sender and the tank is either cork or fiber.  My parts book lists a washer for these screws, but only gives a number code and does not say what kind of washer it is.

Dave

[hendo0601]

I would imagine they are made from copper as it is soft and conforms to irregular surfaces to allow better sealing. I would think that over time the fiber or cork gasket material would absorb liquid and cause the gasket material to deteriorate thus causing leaking. I would try to replace it with rubber if possible and maybe some thread sealer on the screws for added insurance.

[busycoupe]

Rubber is a good idea, perhaps an auto parts store will have some small rubber washers or rubber gasket material. The metal washers I took out were not copper, they were a very thin, soft, silvery metal.

[Merle Coggins]

They were likely aluminum washers serving the same purpose as a copper washer. Rubber washers would probably seal good, but will you be able to get the screws tight enough without completely deforming the rubber? I'd stick with aluminum or copper washers if possible.

 

Merle

[Old Ray]

 On a previous build I had the same problem, gas seeping out from underneath the screw heads, cut some washers / gaskets from a roll of soft copper plumber’s strap, no more leak.  

[busycoupe]

Thanks to everyone for the help. I'll look for some copper washers.

[busycoupe]

Just to follow up, I did find #8 copper washers.  I first went to 3 of the local auto parts stores that I thought had pretty comprehensive inventories and was surprised that they only had  copper washers for oil drain plugs and fuel injectors.  The third place directed me to Ace Hardware.  Our local Ace store has an impressive variety of small hardware and had what I was looking for.   I also replaced the old fiber gasket around the sender unit with one I cut from cork.  Now it doesn't seep gas anymore. 

Thanks to all for the good advice.

Dave