Which gas tank, with or with out vent tube support?
 

I have been looking at some gas tanks for my 1984 f250 4.9. My old one has way too much rust on the outside and inside. The sending unit is nothing but rust.

So this is what i know so far, there are two types of tanks available for this truck. They either have a support for a vent tube or not.

I need to know which gas tank to purchase. The one with the support tube or not? I still have the original plastic tube that goes inside the filler tube. this tank has s]upport tube

Also i have read somewhere that the gas goes through the small tube and that the fumes vent around the little plastic pipe. So today I hooked the filler tube back to the filler neck and poured some gas through it, and the gas came out the big hose not the bottom. I even feed some flexible weed eater string to follow where the gas pump nozle goes, and it does go into the big hose not the small plastic one.

Oh and I was wondering what the small thing on top of the tank is and if it is checkable and or replaceable? A small hose goes to it. I am pretty sure it goes to the charcoal canister however this truck has a feedback carb and so im not sure if it is the return line. Thanks for any help.

It runs into the big hose and the small line is an air return, basically without it it takes forever to fill it up. The thing you are talking about is a "rollover" valve I've also heard it called a vapor release valve. Should you roll your truck it should stop the flow of the gas, but it also is designed to slowly release the pressure in the tank when it gets hot, like in the summer time. As to if they are orderable, not sure I just ran mine.

So if I remove the tube it will take forever to fill up. What if I purchase a gas tank without the vent tube support but still use the tube inside the filler neck. Wouldn't it still work? Cause the tube would still be inserted into the tank, it just wouldn't be stationary because the lack of support. It seems to me that it would'nt really hurt it as long as that tube goes into the tank and the inner tube is still attached to the filler neck.

The reason I ask is because on ebay they have both tanks, which is made buy some company. However on Advanceautoparts the tanks are spectra premium which are suppose to resistant to rust or better protected. Last time I checked these tanks at advance does not have vent support tubes. But today it doesn't say whether it has the support tube or not.

I want to purchase the tank from Advance instead of one of those ebay companies. The description sounds better at advance on their gas tanks.

So would a tank without a vent support work with a filler neck that has the vent tube inside???????????? Also would it affect filling it up with this setup?? I dont think vibrations would hurt since that little tube is plastic and that the filler neck is not hard.

BTW this is a pure farm truck. I dont even think it would be drove a mile a day. Just short little trips, thats it.

Yeah you would pry be fine for your intended use. I will give you an example of what I am talking about. At my fire department we have a late 80's Chevy with like 30k miles on it. Its our rescue, it does not have the vent fill tube and unless you hold the nozzle just right (read as not stick it in all the way and go talk on your phone) it will fill up the filler neck, and spit gas on the side of our truck.

For your use you would be fine.

Thanks for the help. Now I need to find me a replacement tank. I thinking about going with Advances.

I would they have some screaming deals on stuff. I was big on Rock Auto, but some customer service issues have soured me on some purchases. Look online for advance auto coupons. I got a fuel pump/sender, and valve cover gaskets for $117 shipped because of coupons.

If its never going to see the road, I do this with my mud trucks and swamp buggys. I use a outboard boat tank. Strap it down and run the fuel line to it and use the quick connect for hooking to the outboard tank.

Um, some serious problems, you are going to be getting yourself into, if you do this the wrong way.

The tank with the vent on top, that the hose goes to the charoal canister, is for evaporative emissions. It is true that when the truck rolls over it keeps gas from going through the valve, but it's main purpose is to vent air to the tank, and to control the gasoline from evaporating from your tank. Thus saving you fuel and the environment at the same time.

Problems...

A: If you remove the evaporative emissions system, your truck is going to smell of gasoline, as the gas will vent to the atmosphere instead of getting trapped by the charcoal canister. On a hot day you can loose a lot of gasoline to the atmosphere.

B: if you do not change the entire system, tanks, the gas caps, the fuel fillers, etc... there is a tendencey for vapor lock, as the tank will no longer be able to vent properly, and there is a possibility of the tank actually crushing under the outside pressure.

There are two different gas caps for Evap. emissions, verses non evap. emissions, as the evap. emission cap does not vent, only in emergency, but the non-evap cap vents to atmosphere.

For what it's worth, it will cost you more money to get whatever you need to change the truck from evaporative emissions, to non-evaporative emissions. Then there is the downside that you will lose fuel to the atmosphere, instead of it being trapped in the tank. The evaporative emissions system does not harm horsepower, and it keeps fuel in your tank, so why mess with it?

If your truck has Evaporative Emissions, get the right parts for that system. Mixing and matching evaporative emissions parts with non-evaporative emissions parts is asking for trouble, and a possible crushed gas tank.

As for the fuel filler vent hose, leave it alone. Without that hose it will take forever and a day to fill it up. No use removing it.

I feel the need to post here. I am very sorry if it is bumping a very very old thread.

I spent many days researching the internet to find the answer if I wanted the "vent tube support" or not. That search lead me to be a new member of this forum, and why I registered here with my facebook account.

Great forum, great people, great KNOWLEDGEABLE people. Pretty rare on the net, but here it exists.


"Vent tube support" refers to this:

vent tubes are inside the filler neck tube.
vent tube is a "giant plastic straw" that allows easier filling of gas tank
without the "giant plastic straw"

this should not ever be confused with the tank vent piping that is a press fit into the top of the tank.
tank vent piping runs to the evaporative emissions canister inside the hood region of the car.
tank vent piping carries evaporative fuel vapours to a carbon canister to help control the evaporating vapors of the fuel tank, and recover them into the engine as extra fuel.



some tanks move this "giant plastic straw" outside the filler neck.
ford f-150 1980?-1986- 1993 have this straw inside the filler neck.

the 1987 to 1993 tank (i only know and can talk about the 19 gallon midship tank and the 16 gallon midship tank) does not have a vent tube support inside filler neck
ford decided it was not needed and they were right

the vent tube is a 2 inch smaller diameter pipe welded into the inside of the filler tube at the tank
it only supports the vent tube "giant plastic straw"
it is not needed, if you want to have it ok, but it is not needed if you are given the option to choose.

few examples
of same tank with and without internal "vent support" for the tank's filler neck




Notice the price differences, the older style with the tank vent support usually costs somewhat more.

LAST AND MOST IMPORTANT. ALWAYS BE CAREFUL THAT THE LOCK RING FOR THE FUEL SENDER ASSEMBLY IS THE SAME. IN THE EXAMPLES I POSTED THEY ARE THE SAME. AND ONLY THE EXAMPLES I POSTED, I CHECKED THE MANUFACTURES WEBSITE TO CONFIRM THE SAME LOCK RINGS BEFORE I POSTED.

in this case you can see all 4 of them use the same spectra lock ring: "Kit: LO04 (Included)"
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spectra does not allow direct linking to tanks, but each of those is tied to an automobile that has one of the 4 posted links on amazon.


dorman catalog image for the 1996 to 1987 ford f-150/f-250 16 gallon sidemount tanks exact same except the little pipe support that is not needed
http://www.dormanproducts.com/catalo...4FuelTanks.pdf
http://i61.tinypic.com/5xv01t.jpg

Sure is a old thread, here's a new thread about the filler pipes if you didn't find it. It explains the differences between the years and how the 87 and up are better than the 80 to 86 fillers.

https://www.ford-trucks.com/forums/1...-85-hoses.html