Gas cap hissing. Can’t barely pump gas.

[iboughtatahoe23]

When I replaced my canister, while the lines were still disconnected, I blew air into the tank from the filler neck to clean out the lines. I just used an air nozzle and a rag to seal the filler tube. Quite a bit of charcoal came out without having to drop the tank.

Good idea man. Did you do this on a near empty tank?

 

[OR VietVet]

Mine does not do it but it did at one time, I replaced everything and is fixed. Not gonna mess around and piece by piece it. I have gotten in to the habit with all my vehicles and anyone else's I may be putting gas in, and I never stick the nozzle all the way in and I never pump it on the fastest step/click.

 

[tuckerrnr1]

Good idea man. Did you do this on a near empty tank?

No, at least half a tank or more to take up volume in the tank requiring less air.

 

[iboughtatahoe23]

No, at least half a tank or more to take up volume in the tank requiring less air.

OK, I’m going to try this as well as replacing the purge valve solenoid

 

[iboughtatahoe23]

Mine does not do it but it did at one time, I replaced everything and is fixed. Not gonna mess around and piece by piece it. I have gotten in to the habit with all my vehicles and anyone else's I may be putting gas in, and I never stick the nozzle all the way in and I never pump it on the fastest step/click.

Lesson learned. Hopefully get this taken care of

 

[newton4mark]

2014 Tahoe Lt 178k

Changed charcoal canister. And now it’s worse. Don’t know how pellets would have gotten in the lines if I took the hoses off before the canister. Any way. This thing clicks off every few dollars and hisses when I take off the cap. I have to trickle it or use a funnel.

Some youtube videos below:
1) Gas cap hiss
2) Pump clicking off

Had this same issue
Changes all three parts on the evap system and still couldn’t fill up
Dropped the tank and unhooked all the lines and blew them out with compressed air - took a ton of passes
Loaded with charcoal bits
Put it back together and good as new
Nonissue now filling up
I would bet money your lines are clogged

When I took the original canister off
A bunch of charcoal bits fell out
So they got sucked into the lines
It’s pretty common I gues
And a real pain in the ass

 

[iboughtatahoe23]

Had this same issue
Changes all three parts on the evap system and still couldn’t fill up
Dropped the tank and unhooked all the lines and blew them out with compressed air - took a ton of passes
Loaded with charcoal bits
Put it back together and good as new
Nonissue now filling up
I would bet money your lines are clogged

When I took the original canister off
A bunch of charcoal bits fell out
So they got sucked into the lines
It’s pretty common I gues
And a real pain in the ass

Do you really HAVE to drop the tank

 

[solli5pack]

Do you have a scanner? A seal and purge test will tell you exactly what's going on.