Hello. I spent a few hours on this "jackhammer" issue as well. I have a KitchenAid KFCS22EVMS model. In summary I used the "washer" solution approach. Simply, I used a standard rubber washer and put it in from the two "tits". I submersed the filter in a pitcher of water and waited a few minutes for the bubbles to stop. When I installed the new filter (as per instruction), I heard a release of air. I tried the water and no more jackhammer sound and the water flows nicely. What a relief!