I have installed 3 different dishwashers during the 35 plus years at our existing home. With all three installations, I never replaced the waste hose or the air gap. I only replaced the air gap cover from chrome to white.
About 6 months ago I noticed water puddling outside our kitchen sink. Initially I thought, either, my wife, Efiwym, or I, was overzealous when washing something in the sink. Well, it happened again and again, until I finally put two and two together, and it wasn’t four. It was water leaking from the air gap.
I am not going to bore you with the purpose of an air gap for a dishwasher, you have access to Google®. But it is needed if you have a dishwasher. I started looking on the world wide web for the reason why an air gap leaks water. The air gap is connected to the dishwasher waste line and diverts the water to the garbage disposal. So, all this water was waste from the dishwasher. Yuck! Most posts indicated that an air gap would be leaking because the hose to the garbage disposal was blocked.
Taking a suggestion from a YouTube® video, I took a coaxial cable and pushed it through the tube in the air gap. As I pushed the cable down, the end of the cable peaked out of the inside of the garbage disposal. A couple pushes and pulls of the cable, I was confident I cleared the clog.
I put the cap for the air gap back on. As I put the cap in place, I noticed the air gap was brittle and a piece broke off that held one side of the cap in place. Nonetheless, I ran a rinse on the dishwasher to test the air gap fix. You could hear the gurgling of the water as it went through the air gap and then I saw the water spilling out inside the garbage disposal. Success! I put the air gap cover back on and I was done.