69 Skylark gas tank vent leak

[dinknut]

My recently purchased 69 Skylark leaks gas from the vent tube....When I researched this I found that the 69 tank should have 2 vents...Is this correct ? Do i have the wrong tank ( a 70 maybe )....My other question is where do the vent tubes go ? Do I need gas tank vent valves to stop the leaks ? Any info is greatly appreciated .

[bobc455]

I also have a '69, and it has always perplexed me.

You need a vent for a few reasons:
1) When gas is pumped out of the cold ground into the hot atmosphere, it needs to expand (and you don't want to overpressurize your tank)
2) When fuel is removed (i.e. pumped to the engine), you don't want to create a huge vacuum, causing the tank to collapse.

Therefore the tank NEEDS a vent, and you can't use a 1-way check valve or anything.

What I've done is connect my vent tube to a small hose that travels vertically about 3" up, then into the largest fuel filter I can find (which essentially acts as an overflow reservoir when the gas expands). That way the tank can "breathe" but the extra fuel filter will hold [i[]some[/i] of the gas before it pours out onto the driveway.

The fuel filter I used was from a mid-80's crown victoria. It can hold about 2 pints of fuel. The top of the filter has a vacuum cap with the tiniest possible hole that I could drill into it, so it will restrict (but not prevent) air/gas from entering & leaving the tank.

Anyone with a better solution, I'd love to hear it...

-Bob C.

[68gscali]

on my 69 skylark the original vents went to a charcoal can under the hood.i took the can and mounted it in the trunk then just ran hoses to it.seems to work.