fuel tank vent problem

[4alaska]

my 83 m109a3 is pulling a vacuum on the fuel tank when driving and i do not know if this normal or not since this is my first (not last ) deuce . after driving about 50 or 60 miles if you stop and try to remove the fuel cap it has alot of vac pulled on the tank . is there a vent i dont see ?

 

[73m819]

should be a vent line on top of the tank along with a return line, I think the cap is vented also

 

[tm america]

Cap is non vented..the gas tank vent runs up to the firewall there is a breather cap on it pull the breather off drive it and see if that fixes it.. then you will know what you need to do to fix it

 

[Flyingvan911]

As far as I know my deuce's cap is not vented. The factory set up for the fuel tank vent is routed to the slobber tube. I can see there being a slight vacuum while driving but it sould even out at a stop. Your vent line might be plugged up. You might take it off and blow some air through it.

 

[4alaska]

thanks alot i will ck out the vent this weekend its about time for a road trip . again thanks for the info