Gasoline tank replacement?

[Astrodokk]

It's starting to reek real bad of gas and I think I need to replace the tank. Anyone know how to get one? A previous mechanic told me that the tank was loosing the top seal and not to fill it all the way, and that helped for awhile, but now the smell is too strong.

[balrgn]

Not sure how your is installed, but on my 77 the fill hose was dry rot. leaked when I filled and gave off fumes in the cabin. There is no seal. My tank is welded.

[TomW]

Originally Posted by Astrodokk

... I think I need to replace the tank. ... A previous mechanic told me that the tank was loosing the top seal ...

I seriously doubt a new tank is needed; the "top seal", which I assume is the seal between the pickup tube/gas gauge plate, can be replaced. The tank will probably have to be removed to do it, though.

Balrgn is on to something with the fill hose being bad. I would also look for other, smaller, damaged hoses present to either meet emission control standards or catch fuel from a busted fuel pump diagram.

But the kicker is to be prepared to spend some bucks to fix this problem. That fill hose pictured in balrgn's post is expensive, and your existing hose will probably have to be cut to get it off the tank. So plan on buying new hose.

If you decide to drop the tank yourself, remember that gasoline is heavy - either schedule the work for when the tank is empty or come up with a bunch of approved storage containers.

Tom

[GlenCoombe]

I'd suggest the same hose inspection. The top of the tank has often been overlooked when replacing hoses. I lost my feed hose due to rot right above the fuel pickup. Lucky for me the young mechanic's helper could reach up and install a new hose and clamp without dropping the tank. Check all your hoses before going to the trouble of dropping your tank.
Stating the obvious do what you can to reduce the amount of fuel in the tank before undertaking droping it down! Those babies are heavy when loaded and much lighter when empty.
If you do drop your tank it's always a good idea to inspect and replace the fuel sender and pickup while you've got it down.
It's unlikely you'll have a tank problem.

[eubank]

Ditto on checking the filler and other lead lines; they're commonly the first to go. Otherwise, if you don't feel confident in your fuel tank, I'd go with a fuel tank sealant. Using a sealant is pretty common practice among automotive and aircraft restorers. (Just do a Google/Yahoo search for "fuel tank sealant.")

Lynn

[overlander63]

If it really is the top seal, it is a gasket that seals the spot where the sending unit goes into the top of the tank. If that seal is bad, it can be purchased or fabricated. The only reason to replace the tank is if the top is rusted through, or the seam is leaking. If the seam is leaking, you can probably use the tank sealer mentioned above.

[bibbs]

I just had my sending unit rebuilt [gauge problem] the pickup tube was loose where it went through the flange,I sent it to 'www.tristarrradiator.com' in upstate N.Y. on monday had it back on thursday. My 32 year old tank looked brand new inside. A little off topic.But does anybody know what the voltage should be that comes from the gauge and feeds the level sensor?The guy at tri starr said it should be pulsing about 5-6 volts.I am afraid to plug it in now.As mine reads 8 steady volts.

good luck on your tank ,hope its just hoses

Doug

[TomW]

Originally Posted by bibbs

... does anybody know what the voltage should be that comes from the gauge and feeds the level sensor?The guy at tri starr said it should be pulsing about 5-6 volts.I am afraid to plug it in now.As mine reads 8 steady volts...

You did not mention the make/model of your vehicle. But on my '84 Suburban, +12 vdc is applied to one of three terminals on the fuel gauge, and the sending unit's output is tied to another terminal. The third terminal is tied to ground.

The gauge does not feed the sensor per se. The sending unit simply supplies a path to ground with a resistance based on how high the fuel level is. On my 'Burb, if the sending unit is not connected, the gauge will read "more than full".

But under no circumstances does the voltage pulse. Maybe it does nowadays but it was steady in '84.

Tom

[Astrodokk]

Thanks for all the replies. The Chevy truck dealer who did my power steering unit told me that they sealed the tank. I suppose that they never did drop it to inspect, and that he was just assuming it was the weld starting to separate. I'll take it in (to someone else) and have them look at the filler hose and other stuff mentioned above. Thanks!

[eubank]

Humm. When I sealed our old beetle tank a decade or so ago, the tank had to be removed in order for the sealant to coat the whole of the inside, including the top.

Lynn

[bibbs]

Tom,the 12v conection is for the fuel pump.The gauge voltage on its path to ground is what I ment. This is good to know that your gauge has a steady
output,mine is a 75 so I bet I'm good to go!

thanks Doug