TR2/3/3A gas leak on a TR3

[Jerry]

I filled up our TR3A, perhaps a little too much gas. I was following my wife on our way to a car show and the TR3 was leaking gas out of the overflow tube on the gas tank. Has anyone tried just pluging that tupe up?

 

[PeterK]

I think if you plug up the overflow, then it would overflow out the cap on to your rear deck, boot, rear seat area.

 

[Banjo]

Yup. that's also a vent. if you plug it up, it may create a vacuume situation eventually causing a fuel dilivery problem. likewise the vapors need a place to expand. Like Peter said, thay have to go somewhere, like all over your rear deck, or interior, or push fuel past the float needles and cause flooding.
Modern cars have the charcoal canister at the end of that vent hose. (And if you overfill them, all that fuel saturates the charcoal and renders it usless)
In short, don't plug it. Just be a bit more reserved about filling up.

 

[donbmw]

The original tank that was in my 59 TR3 had a baffle that would not let gas come out. When I replaced the tank with a new one it would come out the vent when turning left and when starting out. There was a thread that talked about this and that the fuel cap could be vent. My replacement cap has a small hole for venting. I did block the overflow on the tank and have not had any problems doing this. This has been over two years ago.

Don

 

[TR3driver]

Plugged mine many years ago; never had a problem since.

No baffle that I found on any of my original tanks ... a baffle wouldn't help anyway since the 'overflow' is open all the time and the fuel would simply rise on the overflow side of the baffle until it ran out the overflow.

In my case there were two incidents that led me to plug it; first was having a gas station attendant (remember those ?) repeatedly 'top up' the tank while standing in a spreading pool of gasoline running all over the ground. Second was looking at the ground where I made a hard left turn, and finding a trail of evaporating gasoline ... doesn't take much of a turn to force fuel out the overflow with a full tank !

The cap has a vent hole in it (at least all the TR2-3A ones I've looked at do), and since it is much higher, the filler neck can act as an expansion chamber. Of course, it is possible to overfill until the expanding fuel runs out over the trunk lid; but in some 30 years I never had that problem.