fuel tank leak?

[wilson_wwsc]

Hi, I don't know if this is the correct subform, but I have a question about my 1973 240z's fuel system. When I fill up the tank full, it leaks. Not sure where it is coming from; hoping you guys and your infinite Z knowledge could help me figure it out. Also trying to find a fuel flap. I think black dragon has the cheapest price.

Thanks!

[1 Bravo 6]

G'Day Wilson,

Do a search mate, the problems of fuel tanks leaking has been covered many times in the past.

Rick.

[yoshi_w]

I had this happen to me at a gas station. Not fun and I thought it was the gas tank too. It turned out to just be the fuel line so I would check that first if I were you.

[Powderkeg]

Wilson,

As Bravo mentioned: search. There are several threads regarding tank problems.

The most common problems seem to be: a bad fuel fuel filler hose or worn fuel hoses. You could also have a pinhole leak in the tank. Obviously it's hard to diagnose without more details.

My tank (a 76) leaked like a sieve when I filled up directly underneath the filler mouth. The filler hose (from the filler neck to the tank) had pinholes in them.

In all likelihood you're going to have to drop the tank and replace the offending hose. Of course while you have the tank out you'll want to replace all the hoses, possible coat the tank with POR-15 or equivalent, add a Fram G-3 fuel filter at the gas tank discharge line, check out the condition of the hard lines, paint the tank and underneath... you know... the usual excesses of a relatively simple repair!

Most of the hoses are still available for the 73. You don't need factory hoses (Except for the fuel filler hose) as these can be had at most auto supply stores. The one problem child hose is the long factory 5/8" has with the 180 degree bend. You can get an adapter made by getting section of 1/2 inch stainless steel tubing bent by a good machine shop or muffler shop.

Also make sure to get FUEL rated hoses and not heater hoses.

Download a factory service manual and the articles here on this site and you should be set.

Good luck

Dave Ruiz

[5thhorsemann]

Check the hoses going to the vapor tank, they are a pita to replace, and that was the problem on my 73.

[FastWoman]

Also check the fuel/air separator. Mine had a crack in a solder joint on one of the nipples. It wasn't enough to smell, but it was enough to wrinkle up the black paint on the thing.