Most coaches with air brakes and suspensions have an air hose connection in the engine compartment, or nearby. Ours has one there and one in the generator compartment up front. I expect you could run a hose to connect to that. But I would be concerned that doing so might compromise the air brake system if the hose is damaged.
If it was me, I'd probably rig some way to monitor the car's suspension pressure while driving, and stop to re-air if it gets low.
2008 King Aire 4562, Spartan K3(GT) w/ Cummins ISX, Motosat HD-SL5 w/ SWM-8, Multiswitch, HR34 Genie
2014 Jeep Grand Cherokee Overland 5.7L V8 Hemi w/ Blue Ox Aventa LX Tow Bar and baseplate, SMI Air Force One brake