Hello, I'm Cam. Please include all the details about your issue so I can accurately advise you. I cannot see your vehicle so please be detailed.
Yes this is almost always dirt or ice in the vent valve. On your truck it is under the fuel filler area.
THey get dirt in there and that plugs the canister infront of the tank .
Cam i took hose off of canister and blew air back threw it . do you think this will work? Sorry it was big hose.
Should i blow threw small lines too? I could feel air coming out at vend valve.
Ok i will do that.