Gas pressure build up,comes out of filler

replaced fuel pump,every time I put gas in jimmy,pressure starts to build up
and leaks out of the fiiller,also was running rough,let the pressure out then was running ok until it builds up again,go figure

replaced fuel pump,every time I put gas in jimmy,pressure starts to build up
and leaks out of the fiiller,also was running rough,let the pressure out then was running ok until it builds up again,go figure

Sounds like your vent in the gas cap is plugged.

replaced fuel pump,every time I put gas in jimmy,pressure starts to build up
and leaks out of the fiiller,also was running rough,let the pressure out then was running ok until it builds up again,go figure

Welcome to AF.
What year and engine?
Inside the filler tube is a smaller hose that works as a vent for filling up.
The small hose inside the big hose is off inside or pinched.
Where did you disconnect the filler hose when replacing fuel pump?
MT

Welcome to AF.
What year and engine?
Inside the filler tube is a smaller hose that works as a vent for filling up.
The small hose inside the big hose is off inside or pinched.
Where did you disconnect the filler hose when replacing fuel pump?
MT Hey, thanks for the reply,its a 95,4.3 vortex.I disconnected the hose from the gas tank.it also has a small vent hose next to the filler hose.

If it has the outside vent hose up to the filler cap check it for kinks or being stopped up.

If it is not filling up good it is not venting good someplace.
MT