Fuel Filler Check Ball?

[1project2many]

Years ago when I first converted my truck to EFI I just built a fixture with a float/sender, pump , supply, and return lines and dropped it in the stock tank in a new hole. That was my first EFI retrofit and I didn't realize how much the fuel would heat up and build vapor in the tank and cab. Now it's time to fix it. I'm hoping to install one of the fuel filler valves that prevents the tank from being filled up too far. But I've been in a fleet repair shop for so long I just don't get to see many different vehicles any more. Anyone know of a valve that installs inline with the filler hose (not vent)? Or does anyone have one they removed from a tank or filler they want to get rid of? Or maybe someone's had a tank/filler apart and can give me an application with the valve in the filler neck?

Here's an S10 version in another member's truck which I believe is in the tank, not the neck.

[mknittle]

I have never seen one. but i would bet it is to keep gas from spilling in case of a rollover.I wuoldn't bother messing with it.
Big brother protecting you!

[mr48chev]

One thing I've figured out over the years is to know approximately how much gas your truck is going to take and don't be tempted to add more after the pump cuts off.

Such as: Lets see I just drove 250 miles and the truck gets 18 mpg so it should take right at 13.8 gallons to fill it. If it cuts off at 13 it's full. That leaves a bit of room for expansion.

My big tank in the front of the bed in my 71 is bad to give off fumes if I fill it too full and the filler neck with the vented cap is right at the front left corner of the bed.

[BlueJeep]

Originally Posted by 1project2many

Or maybe someone's had a tank/filler apart and can give me an application with the valve in the filler neck?

Here's an S10 version in another member's truck which I believe is in the tank, not the neck.

That's of my project, and that ball is in the neck, not the tank. I believe it's to keep gas from leaking out the cap when it's full and you go around corners, but not 100% sure on that. I left it in when I modified my filler.

[mknittle]

Still looks like a PITA to me.

[oldcouple]

I have one I took off that has a flapper inside the top to keep it from sloshing out.

[1project2many]

I'm going to add a vapor purge line to the top of the vent hose at the filler neck. The valve is going to help keep the tank from being overfilled. When the fuel level gets high enough the ball "closes" the filler tube and the fill valve on the pump is supposed to click off. The ball will also help keep large amounts of fuel from sloshing up the fill pipe if the tank is near full and you go around a corner. Liquid fuel is not supposed to go through the vapor lines or bad things happen. Yes it's a little more complicated but it's going to require the least amount of modification to the existing system in the long run.

One thing I've figured out over the years is to know approximately how much gas your truck is going to take and don't be tempted to add more after the pump cuts off.

Right now the pump cuts off when fuel is at the end of the nozzle, about 5" from the top of the neck. I usually only fill it until I can hear fuel gurgling in the neck which is a bit lower.

That's of my project, and that ball is in the neck, not the tank.

Thanks. That helps. It was really hard to tell from the picture. Now I know I don't have to cut up a tank to get one.

I have one I took off that has a flapper inside the top to keep it from sloshing out.

Thanks. So far, it looks like the flapper type is mainly for fuel slosh but the ball type does the automatic shutoff as well.

[mknittle]

Then in that case when the ball stops the flow the pump overflows the neck and fuel spills.

[1project2many]

You'd think that would happen but it doesn't. The ball lifts up, pressure in the neck increases, and the trigger in the pump releases. Any fuel pushed into the tank after that can still overcome the ball and get to the tank. That's how people are able to keep adding fuel to a newer car after the pump first shuts off. Now if the fill nozzle is messed up the system doesn't work right but that would happen on any vehicle.