2012 Tahoe/Fuel filler-neck flap

[KidWgn]

Seems silly, but I cannot for the life of me find any information. Does the filler-neck opening have a flapper in it? If it’s supposed to, mine does not, which would explain why I can’t use the locking function on a gas pump after replacing everything else.

 

[B-train]

Year make and model will be helpful. If you have 2015 and newer, then it is capless fill and there is a spring loaded flap that shuts when you remove the gas nozzle.

We don't have those crummy pumps here in the midwest, so I can speak for how ro make them work for filling up.

 

[KidWgn]

Year make and model will be helpful. If you have 2015 and newer, then it is capless fill and there is a spring loaded flap that shuts when you remove the gas nozzle.

We don't have those crummy pumps here in the midwest, so I can speak for how ro make them work for filling up.

12 Tahoe. I figured GMT900 was a given since I posted in the year specific sub-forum gaha

I’m in the Midwest…STL, MO to be exact. What do you mean “those crummy pumps”?

 

[Geotrash]

Seems silly, but I cannot for the life of me find any information. Does the filler-neck opening have a flapper in it? If it’s supposed to, mine does not, which would explain why I can’t use the locking function on a gas pump after replacing everything else.

There is no flapper on the GMT900 filler neck. If you're having trouble with getting the lock on the pump to stay engaged, then I suspect a problem in the fuel tank vent and vapor recovery system. When you say that you replaced everything else, what does that mean in terms of parts, exactly?

 

[Fless]

12 Tahoe. I figured GMT900 was a given since I posted in the year specific sub-forum gaha

You might be surprised how many threads are mistakenly started in the wrong year forum; not necessarily a problem but it happens. Best to add some vehicle info to your signature so it's clearly, well, clear.

 

[B-train]

12 Tahoe. I figured GMT900 was a given since I posted in the year specific sub-forum gaha

I’m in the Midwest…STL, MO to be exact. What do you mean “those crummy pumps”?

I was thinking you had those weird scrunchy ones that have to lock in the down position before they fill. I hate those, they always seem to be a PITA

 

[petethepug]

I was picturing the soft rubber like flap that some vehicles have over the cap that unfolds over the door to the tank. Essentially a protective cover for the lower half of the opening from the pump handle. And .. this isn’t regarding the metal spring loaded flap some vehicles have that’s visible when the cap is off right? The one attached to the inside of the metal filler neck because that doesn’t cause the pump to click off.

If your pump is clicking off (there should be a sticky on this) when filling it’s related to one of these three things …

* The carbon canister full of charcoal pellets.
* Vapor canister purge valve.
* Vapor canister vent valve solenoid and it’s accompanying harness needed due to design change.

Replace them as a trio ASAP or all those little charcoal pellets will get into the fuel system and also gift you with replacing …

* fuel pump
* fuel pump (gauge) sending unit.
* Fuel tank cleaned and lines blown out of pellets.
* A large labor bill for dropping the fuel tank.
* A large parts bill because if you’ve been warned that if you do not get an OEM fuel pump ($250-300). You’ll be replacing it again, 1 day after the Cheap pumps warranty expires. Pay now or pay even more later.

If you wait, you’ll get to do both scenarios. If your lucky it’ll only be the 1st set of parts. At least now you can shop rock auto to get them in your hands for the replacement. Seriously big bills occur if you let this go because if the parts aren’t available locally, the only option is to get them from a dealer or OEM from the part store. I had to spend $5h on my fuel pump & sender because COVID ate the supply line up.

 

[KidWgn]

There is no flapper on the GMT900 filler neck. If you're having trouble with getting the lock on the pump to stay engaged, then I suspect a problem in the fuel tank vent and vapor recovery system. When you say that you replaced everything else, what does that mean in terms of parts, exactly?

Purge Valve Solenoid
Vapor Canister
Vapor Canister solenoid

I was picturing the soft rubber like flap that some vehicles have over the cap that unfolds over the door to the tank. Essentially a protective cover for the lower half of the opening from the pump handle. And .. this isn’t regarding the metal spring loaded flap some vehicles have that’s visible when the cap is off right? The one attached to the inside of the metal filler neck because that doesn’t cause the pump to click off.

If your pump is clicking off (there should be a sticky on this) when filling it’s related to one of these three things …

* The carbon canister full of charcoal pellets.
* Vapor canister purge valve.
* Vapor canister vent valve solenoid and it’s accompanying harness needed due to design change.

Replace them as a trio ASAP or all those little charcoal pellets will get into the fuel system and also gift you with replacing …

* fuel pump
* fuel pump (gauge) sending unit.
* Fuel tank cleaned and lines blown out of pellets.
* A large labor bill for dropping the fuel tank.
* A large parts bill because if you’ve been warned that if you do not get an OEM fuel pump ($250-300). You’ll be replacing it again, 1 day after the Cheap pumps warranty expires. Pay now or pay even more later.

If you wait, you’ll get to do both scenarios. If your lucky it’ll only be the 1st set of parts. At least now you can shop rock auto to get them in your hands for the replacement. Seriously big bills occur if you let this go because if the parts aren’t available locally, the only option is to get them from a dealer or OEM from the part store. I had to spend $5h on my fuel pump & sender because COVID ate the supply line up.

The metal spring loaded flap is exactly what I was referring to. I found a thread from a different vehicle forum where someone's had broken off and dropped down the filler neck, causing liquid fuel to back up in the neck.

I've already replaced those three items. I did not, however, replace the harness. Why would the harness need to be replaced?

I've already succumbed to the notion that I'll be dropping the tank come summer, and will end up putting a larger pump in it anyway for future performance modifications. *sigh*

When I dropped the original charcoal canister, I didn't hear any loose pellets shaking around in there. After replacing the 2 easy items, with no results, I went ahead and replaced the canister anyway, hoping to solve the problem.

I'm at a loss here, folks. Guess I'm dropping the tank.

 

[petethepug]

That vent valve solenoid harness connector is mentioned because GM changed the harness connector style. They actually sell the shorty adapter harness to make it plug n play.

On my truck all the above stuff was replaced, in that order, then all the injectors and o2 sensors. At almost 170k clicks all the parts were pretty much replaced without diagnostics. No matter what you replace at this milage it’s considered regular maintenance.

Like you’re doing, the replacement parts can be upgraded for just a few dollars more.

 

[Geotrash]

Purge Valve Solenoid
Vapor Canister
Vapor Canister solenoid

The metal spring loaded flap is exactly what I was referring to. I found a thread from a different vehicle forum where someone's had broken off and dropped down the filler neck, causing liquid fuel to back up in the neck.

I've already replaced those three items. I did not, however, replace the harness. Why would the harness need to be replaced?

I've already succumbed to the notion that I'll be dropping the tank come summer, and will end up putting a larger pump in it anyway for future performance modifications. *sigh*

When I dropped the original charcoal canister, I didn't hear any loose pellets shaking around in there. After replacing the 2 easy items, with no results, I went ahead and replaced the canister anyway, hoping to solve the problem.

I'm at a loss here, folks. Guess I'm dropping the tank.

Were you experiencing the slow fuel fill before you replaced the canister and the other components or did you do it proactively? If the former, I would wager that even though you didn't have pellets falling out of the canister that you still have an obstruction in one of the lines and they will need a good blowing out. Some folks here have had success without dropping the tank.

FWIW, my 2012 still has the pump click off a few times during most tank fills, even though I replaced my canister last year as preventative maintenance.