'97 E300D

I replaced the shutoff valve(& its o-ring) to fix a fuel leak. At the same time I replaced the main spin-on filter and pre-filter(& its o-ring) and most of the o-rings on the snap-on fuel fittings.

Now I have an air leak that I can not locate. The bubbles are worse in the morning. The car starts and runs fine.

Three questions: 1) if car performs well, then can I ignore the leak?

2) If I ignore leak will I damage something in the long run?

3) I used the same size o-rings for all snap-on fittings but the drawings of the system I've seen indicate maybe different o-rings are used. Are all o-rings for the snap-on fuel fittings the same size?

__________________
Neil
1997 E300D - naturally aspirated
280,000 miles (as of November 2015)