Filler neck question?

[rusty ol ranger]

I dropped the tank on my B2 today and found this....

Something tells me thats not factory.

A new filler is 117 bucks so im not opposed to running this as long as it wont cause issues....like constantly shutting off a gas pump.

Input?

 

[JoshT]

That's factory or a copy of it. When you fill the tank fuel actually flows down that inside tube into the tank, the outer is the vent/breather which is supposed to help prevent the pump constantly shutting off due to fuel backing up in the filler neck. Later models went to a second tube for the vent, but earlier models had the tube within a tube.

 

[Hoosierman]

Can also help confirm this is normal for older fuel systems. I spent seven years working at a factory that produced entire gas tanks from blow molding to welding and assembly. Modern gas tanks largely do not rely on inner tubes anymore, most of the ventilation is done through other means now.

Of course, older gas tanks also didn't typically utilize slosh baffles, ROVs, or even ICVs. It largely depends on the automaker and their needs.

 

[Uncle Gump]

Looks just like the one in my Bronco II.

 

[rusty ol ranger]

Well damn ok.

Ive only dropped a handful of tanks and dont recall ever seeing that.

Granted the ones ive done were all like late 70's and back vehicles.

 

[alwaysFlOoReD]

Can also help confirm this is normal for older fuel systems. I spent seven years working at a factory that produced entire gas tanks from blow molding to welding and assembly. Modern gas tanks largely do not rely on inner tubes anymore, most of the ventilation is done through other means now.

Of course, older gas tanks also didn't typically utilize slosh baffles, ROVs, or even ICVs. It largely depends on the automaker and their needs.

What is ROV and ICV?

 

[Hoosierman]

Roll-over valve and inlet control valve (the part that connects the filler pipe to the tank). I believe ROV's have been around for some time now. You also have FLVVs which I mostly saw in Nissans. But for the life of me I can't remember what those stand for.

 

[Hoosierman]

Full Level Vent Valve. It just hit me. It prevents a gas tank level from going past a certain amount. That's how I understood it to mean in the part description...