[macojoe]

The vent is not as important but I would change also!! If that were to go bad it can mess things up bad! My boat when i got it the PO said tank was no good, after removing the floor cover and cleaning out the tank it was still messed up? After further research the vent cover was rotted to a big clump of white crap, so not working. after that It has always worked great!
So yes replace all while your in there and cross that off the list!