I have power going in to my 40/20 pressure switch, but there is no power going out from it. Does this mean that I need to replace it?

Depends on the water pressure in the tank. Are the points of the switch closed? How do you know there is no power leaving the switch?

I assume your referring to a pressure swich on a well pump, I suggest you disconnect the power supply and inspect your terminal connections and the contact points, if the contact points are dirty you can clean them with sandpaper an that should restore function to your pressure switch.

Mad, does your switch have a reset lever on the side? If so, have you pulled that to reset your switch?

Short of that, are the points closed and in contact? If so, then you might try cleaning them as suggested above. If they are open, then your switch might be bad.