Keith,
Are you sure that the air leveling system is not an HWH system? Regardless, it sounds like your electric compressor for the leveling system is not working. If it was functioning properly, you would never need to air up the coach to maintain level. Many of the electric air compressors that are used in air leveling systems are not sealed to prevent failures from road water or dirt, especially the Thomson compressors used in most HWH systems. Therefore, to correct the problem, you need to either change over to a sealed compressor like a Viair or fabricate a weather proof housing for the compressor after replacement or repair.
The ride height sensors on your coach are only used for the air suspension. The air leveling system uses a sensor to determine if the coach is level and not the ride height sensors.
Gerald