Does the fuel cap cover lock? It is teed off the passenger door lock, so it should not lock.
The common area for the air line to break is in the corrugated tube at the top of the hatch on the passenger side or the similar hose at the bottom of the passenger door.
It can be fixed in these areas using a larger hose over the yellow hose. Do not use PVC hose use urethane hose as PVC cracks after time.
If it is a hose you might hear a hissing sound.