About 10 years ago, I replaced the air compressor blower on my septic tank after the old compressor stopped working. It took many phone calls to finally a business that would sell a new compressor to me [public]. Most told me that they only sold to plumbers and not the general public.
A few days ago, I walked by my A/C unit and noticed that the septic tank air compressor was making a little noise. I disconnected the hose going to the septic tank and found that it was not blowing any air.
Back 10 years ago, after buying a new compressor for ~ $ 275 I took the old unit apart to see if I could tell what was wrong with it. The "inside" pump is very simple. It is just 2 rubber diaphragms that vibrate back and forth. The rubber diaphragms had torn, causing the pump to not work.
This time, I looked online but could not find anyone that sold parts. A phone call to the manufacture and I found out that parts are sold through distributors. Another phone call and 5 minutes later I had a "repair kit" on order for $ 77.
The parts came in 3 days later and in 30 minutes I had the septic tank air compressor back in service.
Doing this myself vs. calling a plumber probably saved $ 300 - 400.
First pic. is the old torn diaphragms. Second pic. is after I put in the new diaphragms.
I hope this information can help another SC.