I had my pump replaced last week and had no problems until Sunday.
I have a galvanized pressure tank. The pressure tank does not fill before the pump shuts off, it basically empties and then the pump comes on. I end up with air in the lines.

The pressure tank does not fill before the pump shuts off.
A pressure tank isn't designed to fill completely, (see images).
If it did your pump would run every time you flushed or drew a glass of water. What's the settings on your control box? Let me know. Tom

Do you have an automatic air valve? See the web page below.
How to restore lost air in a building water pressure tank - private pump and well system do-it-yourself repairs (http://www.inspectapedia.com/water/WaterTankAir.htm)