Hi Stan, as the others have said, your Leveling system will use the air from the main tanks (see the diagram below from HWH). Of course these leveling systems vary somewhat from Coach to Coach, but basically they would be similar to the diagram.
The air for the air leveling comes from the main (front and rear) air tanks and is fed through the HWH "6 pack" valves, and then to the air bags. When the Coach is in auto-level mode, the air bags are "isolated" from the main air tanks, so the tanks can lose all their air pressure but the air bags will stay inflated. And on most systems, if the air bags do lose/leak air, and the tanks are empty, an electric air compressor will come on and add air to the bags (note that the electric air compressor does not fill the air tanks).
Some Coaches have an extra set of small air tanks called "ping tanks" but these are just for airbags and don't supply air for other things.