Kitchen sink sprayer leaks down the hose to under the sink

take the old one to home depot and have them find a replacement

Maybe just loose or needs a O ring.

should be able to just push hose up from under sink and thread sprayer head back on

Delta comes with a limited lifetime warranty. call them to get free parts. I believe you will need to check several things. Remove the spray head from the sprayer hose, point the hose into the sink drain and turn the faucet on. If it no longer makes the banging noise, replace the spray head. You need to look for a leaking spray hose under the sink also. If the faucet is making noise, replace the ball and cam assembly under the faucet handle. One other thing that I have run into is that the shut-off valves under the sink can also go bad and cause banging and vibration.

If it's from the fitting where the sprayer head is attached to the hose check to see if there is a rubber washer. If the leak is not from the lack of a washer or damaged washer. Uninstall and take back for a replacement. There is nothing wrong with what you did. It should not be leaking.

Disconnect hose from sprayer unscrew nut on sprayer head remove washers and you will see a small c shaped clip get that apart then remove hose and thread it back on under sink and feed it back up through sink and reconnect to sprayer

Remove spray head then faucet tighten connection on the spray hose

although it is possible that the spray head has gone bad, it is more likely that the diverter mechanism inside the kitchen faucet needs replaced. When this part is defective, it allows full pressure from the faucet to go to sprayer head even though the sprayer is not triggered. The sprayer is not designed to handle full pressure when it is not spraying.

It may also be a missing weight on the sprayer hose, or that the sprayer hose is obstructed. Open up the cabinet under the sink and look a half-loop of the sprayer hose that should be hanging down from the underside of the faucet. It must be able to descend without obstruction as you return the sprayer to the body of the faucet. If it is resting on a box of dishwashing soap or otherwise obstructed, then it doesn't have it's full weight to counterbalance the weight of the sprayer head. Capice? It needs the weight of the hose to 'weight it down'. Also, there should be a donut-shaped weight around the hose that should be able to freely slide to tha lowest position of the half-loop as the sprayer is extended and returned. Make sure that's working too.