Diaphragm Assembly Set for Airmax KoiAir 2 (KA40)
The KA40 delivers more air volume than the KA20 and sees proportionally more wear on its diaphragm over time. When air output from the KA40 drops, the diaphragm is the first thing to check. This replacement assembly set includes all components needed to rebuild the diaphragm chamber and restore full air delivery capacity to the KoiAir 2 KA40, extending compressor service life by years at a fraction of replacement cost.
| Compatible With | Airmax KoiAir 2 (KA40) aerator |
|---|---|
| Kit Contents | Diaphragm assembly, all seals and replacement components |
| Replace When | Diffuser bubble output is reduced; compressor sounds more labored than normal |
| Service Interval | Every 2 to 3 years under normal continuous use |
How to Replace
Unplug the aerator and disconnect the airline before disassembly. Open the compressor housing per the KA40 service guide. Remove the old diaphragm assembly carefully, noting orientation. Inspect the housing interior for debris before installing the new assembly. Reassemble and run the aerator to confirm diffuser output returns to normal. Compare to baseline. Both diffuser sticks should bubble evenly.
Fits the Airmax KoiAir 2 KA40 aerator only. Confirm your aerator model before ordering; the KA20 and KA40 use different diaphragm assemblies.

