Have 2008 HR Navigator with PowerGear Air/Hydraulic leveling system. After auto leveling, it is supposed to monitor levelness of coach and adjust periodically. In the manual it states that if the coach air tank pressure drops below a certain point that an aux air compressor kicks in and raises the pressure so the auto leveling system will continue to auto level. Does anyone know where that addition compressor is? Thxs as always for the help.