Capless Gas Overflow

mada2885 · February 21, 2019

I did a quick search but didn't find anything really similar.

I have a 2018 Sierra I got a couple months ago. This is my first experience with a capless fuel system as my previous truck was a 2015 Sierra. Twice so far I've had substantial overflow when fueling up at two different gas stations. I'm very careful when filling up and I fully insert the nozzle and pump only to the first click indicating it's full. That's where the problem seems to be. At that click gas spills out and then down the side of my truck. I've had to thoroughly wash and wax the area twice now and it's becoming pretty annoying. Not to mention I don't want any paint damage.

Does anyone have any thoughts as to why this might be happening? Am I doing something wrong? Thanks.

aero10 · February 21, 2019

Were the overflow incidences at the same pump? If you're putting the nozzle in all the way, it's going to be the nozzle's fault if it overflows on/prior to the first click. I have a 17 with 35k and don't think I've ever had an overfill.

mada2885 · February 21, 2019

6 minutes ago, aero10 said:

Were the overflow incidences at the same pump? If you're putting the nozzle in all the way, it's going to be the nozzle's fault if it overflows on/prior to the first click. I have a 17 with 35k and don't think I've ever had an overfill.

Thanks for the reply. They were at different gas stations.

JimCost2014 · February 21, 2019

5 minutes ago, mada2885 said:

Thanks for the reply. They were at different gas stations.

Welcome to the site. Others have mentioned to put the nozzle in all the way, and then "back it out" a half inch or so, and it stops happening.

Neb15 · February 21, 2019

I had spills with the capless system on my first few fills too. The nozzle has to be just so as others mentioned. I also leave it for an extra 30 or so seconds after filling before removing. It seemed to me to be fuel in the hose that spills out upon removing rather then over filling.

rgoldwing · January 23, 2021

I have a 2019 Sierra 1500. I have the same issue with gas spewing out when filling. If I am lucky enough to be able to hear the tank filling, I can stop it from happening. If filling at slow speed, it helps but still spews some fuel. Maddening.