MOST Diesel air bag systems will have a hard time fully inflating when you have your jacks extended. The reason is the ride height arms for the Air bags. So, retract the jacks first then air bags. BUT, you can accomplish BOTH by starting the engine, hitting the Jack retract and let the system retract AND air up the bags. UNLESS, you have the chrome air bag lever on your console for the air bags. If so, put the lever in fill and not exhaust. Also, IF you do NOT exhaust the air bags when setting up at campsite and you extend the Hydraulic levelors, once the jacks hit the ground, the air bag ride height arms will be tripped and after a few minutes the air bags will then exhaust. BUT, doing this will cause your RV to sit HIGHER. LESS stroke raise on the Hydraulic jacks. That is why you dump the air before leveling jacks are deployed. Doug