Step 5 · Reassemble and Test After Cleaning
Once everything has been cleaned and the hose is reconnected, reassemble the air gap on top of the sink. Place the plastic cap back on, followed by the decorative cover (screw or snap it back into place). To test your work, run your dishwasher on a 'Rinse' or 'Drain' cycle. This will force water through the system. Watch the air gap closely to ensure no water leaks from the top. Also, check under the sink to make sure the hose connection you worked on is dry and not leaking.