Fuel tank leaking...

[usafdarkhorse]

I bought a 76 280Z this past weekend, great car, great mechanically, has a few little electrical issues, but yesterday I was working on the car and I noticed a small puddle about 6" in diameter under the back right side of the car.:mad:

I bent down and looked up under the car and noticed the right side of the fuel tank was wet and drips were coming from the drain plug ( although this may not be the source of the leak). Any ideas on what to do next?

I'm thinking about taking it off and refurbishing it, but I want to make sure it would be a better decision than out and out replacing it ( because finding another fuel tank might be difficult and expensive).

It's a great car ( perfect dash and seats), but it just has a few issues to resolve to make it perfectly reliable. This was just an annoying setback.

[BRE-240Z]

Was the fuel originating at the drain plug, or is that just where it was dripping from? I'm guessing if the whole side of the tank is wet, it's coming from somewhere else, right? Just dripping from the plug because that's the lowest point on the tank?

A few members have had some success in sealing tanks, even ones with small pinholes, but you will probably want to drop the tank and evaluate it before you decide what to do. Either way, be very careful...working with a fuel tank can be dangerous business.

[usafdarkhorse]

What do you suggest would be the smartest way to take the thing off safely?

The drips were coming from the plug, but I can't really tell you if that's where it is originating from. I think it's probably corroded and needs a good refurbishing anyway.

[BRE-240Z]

What do you suggest would be the smartest way to take the thing off safely?

Unscrew the drain plug, and let the fuel run out into another container. Then you'll be able to remove or 'drop' the tank and see exactly where the problem originates.

There is a lot of information on this site about how to drop a Z's fuel tank, so using the search tool will give you a lot of info on how to do this safely and easily. Having a gunked-up or rusted out fuel tank is a very common issue with Z cars.

[280~Master]

Not trying to be rude but do a search and you will find what you need to do this job right. POR 15 the darn thing and be done. Mine had pin holes and now they are gone.

[EScanlon]

In order to save you a bunch of hazzle with a big pan of gasoline, use a plain old syphon hose to drain out the tank into a gas can as much as possible. That way you'll only be dealing with at most one or two gallons of liquid, maybe less.

Then after putting a pan beneath the drain hole, remove the plug. Allow it to drain as much as it will and then jostle the car to drain any that may still drain out. Replace the plug and then follow the suggestions on most of the fuel tank removal posts on the site (they're numerous and all of them explain what to do, no need to re-post everything here).

The POR method has worked for me and others. It is truly a much cheaper proposition than the other processes available and in some instances the ONLY way to go since replacement tanks are .... unobtainable.

Biggest problem you may encounter is that the 280 tanks had a screen filter inside the tank, that may be a major problem that will not allow you to POR the tank. But that's been covered on another post as well, even with pictures.

2¢

E

[Nissanman]

....and it might be as simple as a new washer on the drain plug:devious:

[Walter Moore]

Another method to partially drain the tank before taking out the plug is to use the electric fuel pump to pump all the fuel that it can into another gas can.

I have done that on other fuel injected cars. You have to somehow jumper on the pump with the engine off and the fuel line disconnected up near the engine. Just be sure you shut that pump off as soon as the fuel stops flowing to prevent damage to the pump.

[EScanlon]

....and it might be as simple as a new washer on the drain plug:devious:

.....so very true!!!

I'd still worry about the threaded plug not having sealed it, but that compression washer is there for a purpose.

E

[usafdarkhorse]

Another method to partially drain the tank before taking out the plug is to use the electric fuel pump to pump all the fuel that it can into another gas can.

I have done that on other fuel injected cars. You have to somehow jumper on the pump with the engine off and the fuel line disconnected up near the engine. Just be sure you shut that pump off as soon as the fuel stops flowing to prevent damage to the pump.

sounds risky haha

alright, I've searched for methods on taking the tank off ( by recommendation ), but to no avail. Can anyone find these mystery plans on the correct ( or maybe just best ) way to take off the fuel tank? I seem to be unable to find it. :stupid:

Once I have it off, I'll inspect it for the washer and plug but I might just have the tank coated anyway as a precaution.

[EScanlon]

Here's the tech article on doing the POR 15 inside the tank. It's written by Dogma420 and it is quite thorough:

http://www.classiczcars.com/forums/showthread.php?t=19034

The fuel tank is pretty much straight forward, although I couldn't find one of the various procedural posts on it. If you're mechanically inclined, the hardest part is disconnecting the fuel filler hose and that is accessible through the panel in the right hand wheel well.

Have you bought the Haynes or another manual on the car? They'll explain all the steps much clearer than a re-write by one of us here. Then again, someone may have already taken the time and written it up. Anyone?

HTH

E

[EScanlon]

Here's the best compact explanation on dropping the tank I've found:

http://www.classiczcars.com/forums/showthread.php?t=5876

E