I have a 2011 Chevy tahoe I have taken to dealership already for the gas tank not filling but shutting off.A new canister was installed did not help

[Geotrash]

I have never heard of that. The vent valve is replaceable, it’s not in the tank. Strange.

I think he may be talking about a different model of Cadillac than an Escalade. If so, then it may be a different type of design, but I also agree with your point that there should be no reason to replace the gas tank. I have never seen a design where the fuel and vapor management apparatus were inseparable from the tank itself. That would indeed be a stupid design for serviceability.

 

[OR VietVet]

Well it comes up on my dash "Tighten gas cap"

In the NBS rigs it does not say that and I had no idea that the NNBS spells it out for you like that. Sorry for my comment. If that message ever tells you to bet on one football or another, please let me know.

 

[09_4WD_YUKON]

I have never heard of that. The vent valve is replaceable, it’s not in the tank. Strange. I do know there is no such thing on the NBS- I’ve had my tank out.

Could be a ploy to sell a $800 gas tank!!

 

[09_4WD_YUKON]

In the NBS rigs it does not say that and I had no idea that the NNBS spells it out for you like that. Sorry for my comment. If that message ever tells you to bet on one football or another, please let me know.

It's all good. Sometimes I think these things are too "smart." I spent over $800 just fixing my driver's seat, ended up replacing the wiring harness in it and that thing had more wires than my 86 C-10!!!

 

[zbad55]

I have never heard of that. The vent valve is replaceable, it’s not in the tank. Strange. I do know there is no such thing on the NBS- I’ve had my tank out.

Inside of these tanks as well as all new fuel tanks we have inside the tank a valve that is called an FLVV (Fill Limit Vent Valve). During a refueling event this valve pushes the vapor thru the 5/8 line to the vapor canister. As the valve rises this will determine the shut off point of the fuel. If this valve fails it will not allow the vapor to pass thru, so you will get a nozzle shut off. These don;t fail very often but they are not serviceable and require a new fuel tank. Hope this helps,

 

[OR VietVet]

Inside of these tanks as well as all new fuel tanks we have inside the tank a valve that is called an FLVV (Fill Limit Vent Valve). During a refueling event this valve pushes the vapor thru the 5/8 line to the vapor canister. As the valve rises this will determine the shut off point of the fuel. If this valve fails it will not allow the vapor to pass thru, so you will get a nozzle shut off. These don;t fail very often but they are not serviceable and require a new fuel tank. Hope this helps,

"These tanks" meaning 2007 and newer or are you saying the NBS tanks have the same valve?

 

[Rocket Man]

Inside of these tanks as well as all new fuel tanks we have inside the tank a valve that is called an FLVV (Fill Limit Vent Valve). During a refueling event this valve pushes the vapor thru the 5/8 line to the vapor canister. As the valve rises this will determine the shut off point of the fuel. If this valve fails it will not allow the vapor to pass thru, so you will get a nozzle shut off. These don;t fail very often but they are not serviceable and require a new fuel tank. Hope this helps,

Never heard of that, thanks. Now I’m off reading up on these valves but I can’t find much info on these in our vehicles. Do you have experience with a FLVV in one of our trucks?

 

[zbad55]

Here is a picture of what we use at GM, I have a lot of experience with these as I am a fuel system lead designer at GM, for full size trucks and SUV's working in advance development. The fuel tank in question is mounted on the rear of the fuel tank and is welded internal to the fuel tank. That is why it is not able to be serviced. We have been using these style valves since the GMT900 program. Hope this helps,

 

[OR VietVet]

So my NBS is safe from thise potential problem, thanks.

 

[Rocket Man]

Here is a picture of what we use at GM, I have a lot of experience with these as I am a fuel system lead designer at GM, for full size trucks and SUV's working in advance development. The fuel tank in question is mounted on the rear of the fuel tank and is welded internal to the fuel tank. That is why it is not able to be serviced. We have been using these style valves since the GMT900 program. Hope this helps,

View attachment 385426

Now we have someone to blame for the evap system!