I’m in the process of switching my diaphragms on my P3 to the double diaphragm/double rubber gasket like it says on the link below. When I took my diaphragm caps off I only had one gasket and diaphragm. The main question I have is about the seat and seat retainer as it lists in the link below. I currently don’t have the seat or seat retainer in any of my three horns. I have the old cast p3’s so I don’t know if the seat and seat retainer is something new or if they are used to put a limit on the loudness? Are they supposed to change the sound? If anyone could tell me what they are for I would appreciate it.
http://www.airhorn-al.com/nathanairchimes/type_p_maintenance.pdf