air in fuel system

[BIGREDGLASS]

i changed my secondary fuel filter recently (as well as main filter). I had my wife turn the key on for a second to fill the bowl up before putting the filter in. i noticed a lot of air bubbles coming up in the fuel during and after the filling up process. it filled up really fast but after she turned the switch off it had bubbles coming up for prob 7 to 12 seconds. is this normal at all? the truck is running rough cold. just wondered if this could be related. a tech has my truck right now to look for the problem, but i just thought of this. thanks

[bismic]

Sounds like the primary filter cap may be cracked, have a bad o-ring, etc.

[BIGREDGLASS]

i put new o ring on it when i changed filter but i had a time getting it tightened down. had to put a lot of force on it to get it to tighten that last 5 or 6 turns. also had a hard time getting it off. i think ill take the cap off and check threads on it and reinspect it or cracks.