The Secoh EL80 being the most common septic air pump of the Secoh brand is also one the easiest to rebuild. Like all diaphragm pumps in septic, you will want to check for red dust in the aerator If there is buy a new one. Thes kit works on all Secoh 80 models.
The rebuild kit has everything you need:
4 Shims for magnet alignment
2 Chamber block