2008 Yukon gas tank issue.

[Fless]

It (overfilling) has to happen only once in the past to get fuel in the canister. Or are you saying that the tank has NOT been filled since changing the canister? It's not clear to me.

 

[iamdub]

I have a 2012 Denali that started having the problem of fuel pump clicking off every few seconds. I replaced the EVAP canister and the solenoid valve. When I disconnected the vapor line going between the tank and canister I saw carbon pellets fall out of the line. I used a vacuum to try and suck them out. Put it all back together and no change the pump still shuts off. I assume there is carbon in the line clogging it. Can the line be cleared without dropping the tank?

Maybe, but likely not. There are hard lines attached to the tank. Some run out of one area, along the outside, then back into the tank. Then there's the EVAP purge line from the intake manifold that comes off the frame to the tank. Really, I think you should just one-and-done it. There are too many lines everywhere and a few with inaccessible ends on top of the tank. If you're set up to get underneath it to try to clean the lines, you may as well go all the way and drop the tank. Do it right or do it twice, ya know?

Also, do NOT use high pressure to try to shotgun the pellets out of the pipes. You'll make things worse. Use light puffs or a vacuum. When putting the tank back in, remember to route that large vent hose OVER the cross member. You'll see the one I'm talking about when you drop the tank cuz it'll be on top of the cross member and you'll see it being pulled as you lower the tank.

 

[testdepth]

After using a vacuum and a leaf blower I was able to get the carbon out of the vapor line. The leaf blower hooked to the fill tube and the vent line on the canister disconnected. I verified the line is clear and plenty of air blowing out and no more charcoal. I ran a borescope down the fill tube all the way to the stainless mesh in the tube and saw a pile of carbon in there along with what looked like leaves. I ran 3/8 poly tubing down to the mesh and sucked the crap out. I then ran back up to the gas station and had no problem filling the tank. What a PITA! Thank you for all your help and advice.