ddunne69, you said "I pulled the air line off of each shock, and air is coming out much more forcefully to the driver's side shock. Does this necessarily mean there is a leak in the line on the passenger side?"

Were you trying to add air when you said it was coming out the drivers side more forcefully? If so you may have a kink on the line to the pass shock slowing (or stopping) the air flow to that side. That or somekind of blockage would expain why only the pass. side is low. If they are tee'd at the back they should both always be the same pressure.