I recently changed the water filter in my KitchenAid Surperba KSRS251 Side-by-side. It is 10-1/2 years old. Immediately after changing the filter, I realized the water dispenser in the freezer door malfunctioned. I don’t know it was purely coincidence??
When I remove a glass from the dispenser, the tab that depresses to start the water flow does not return to the off position by itself and the water continues to flow. When I pull it forward by hand to the off position, the water still continues to flow for maybe 4 seconds before it finally stops. :mad: Is there anything I can check and / or fix myself before calling a repairman?
Remove the dispenser front panel and inspect the parts inside. Post the results.
The model number you posted is incomplete. Verify and repost it please.
Gene.
After my posting, I found this posting and reply. I tried flushing my water dispenser for maybe 2 gallons and it completely fixed the problem! 
"It might be something is hooked up wrong, but first I would make sure you got all the air out of the system. If there is any air in the water bottle (the part that stores the water in the fridge) then the water coming in compresses the air and after you have released the switch the compressed air continues to push water out.
Try flushing it out by getting at least three gallons of water out of the dispenser. Try to make sure all the air is out"
Read more: http://forum.appliancepartspros.com/refrigerator-freezer-repair/111458-water-dispenser-doesnt-shut-off-quickly.html#ixzz23k9TEapC
http://forum.appliancepartspros.com
— Begin quote from maroondawg67;762985
…When I remove a glass from the dispenser, the tab that depresses to start the water flow does not return to the off position by itself and the water continues to flow…
— End quote
The problem as you described it in your first post has nothing to do with air in the system.
Gene.