Ok, When I was a Younger Man, and I Had A Full head of hair. Girls would........Oh Never Mind! LOL My Father Lived about 90 miles Away So I knew there was a Slim to None Chance that he would Come and Fix My "Thumper" So he Basically Told me How to Fix it. My Dad had a Weird Sense of Humor so I Cautiously Listened and Wrote down the Parts I Needed and instructions. Half Expecting that when I was done the Whole Sink would Come off the Wall and the Sprayer Hose Wrap around My Leg and Jettison me To a Nearby Outer Space Satellite! So basically What I installed a thing Called a "Ballast" it is Made of Copper and it is around 1-1/2" around and 8" Long and Shaped like a Hot Dog, and one end is Rounded and Closed, while the Other is Tapered down to Around 3/4" and Opened.. At the The opened end, a "T" is Soldered on and the "T" goes in your Copper Pipe Supply, as Close to the Sink Screw on Supply Lines as Possible, but not Past Them. Then you Sweat the Ballast(S) on to the Copper Pipe(Hot) and I Also put one on the (Cold) as Well. Make Sure that the Ballast(S) are in a UP (Vertical) position or they wont Work. The Reason is ,these Ballasts Create a Little Pressure ,just enough to Push the Water through at a Constant Rate. Well after I Installed them, it took me a Couple of hours I Cautiously turned the Main Supply back on and Went back in the House, turned on the Water and "WOOSH" (nope Im still Here) The Water not only Seemed to Come out More Smoothly, There was no more "Thump" Hope this Works for You!