Could someone please me tell what this does:


This connects to one of the two vent lines that comes out of the gas tank. Looks like it might be some sort of check valve or aerator. I'm wondering if it's necessary for a TBI to carb converted Camaro (which is what I'm working on) and could be removed and then the line coming out of the tank capped off. I don't see why not. All the carbed cars I have ever worked on that used a charcoal canister just use one vent line running straight from the tank to the canister. I hope I don't need it because I'm missing one of the hard lines that's part of the line to or from it.

 

It's the vent valve. I wouldn't particularly want to be without it.

 

Why do you need two vents for the gas tank, and one that has this valve attached to it? Maybe it served some purpose when this car was fuel injected, but for a basic carburetor set-up it seems to me one vent line for the gas tank is enough. I've never worked on a carbed car that had such a contraption.

 

That one is a check valve. Its purpose is to let in air to replace the gas that's being drawn out. So yeah, you kinda need it.

Hard lines are eeeeeezzzzy. Just pick up a stick of brake line down at the corner parts store and bend & flare it as required.

 

It's the forever dangling dingus of death, omit it at your own peril ........

seriously

 

It's the UFO valve. It sends out a signal to alert the aliens when you are driving on an isolated road out in the middle of nowhere at night.
Then they beam you up and give you an **** probe.

 

[robert stack]Cavity searches for all...[/robert stack]

 

All you would need to do to do that air exchange would be to switch to a vented gas cap or use a rollover vent valve. I'm sure all this device is there for is to control emissions.

I always hate trying to make fuel or brake lines when I don't have anything to copy or don't know how it's supposed to look.

 

The car has a rollover vent valve.

A vented gas cap defeats the emissions function of that valve. It's a check valve: allows air in but not out.

So yeah, you can "do without" it by way of various hacks and workarounds; but it was put there for a reason, to make the system do what it's supposed to do in the way it's supposed to do it.

There's plenty of photos on this site of those lines. Search for "vent valve" or "UFO valve" and go through the posts that come up.

 

The only picture I could find is one of the valve installed in the bracket with the nipple that sticks thru the bracket left open. Is this how it's supposed to be?

 

Yup, that's it. It just kinda clips in there.