Taking it apart shouldn't be that hard. Get some silicon grease, and
grease things up good -- seals, and threads. That should do the trick.
Be prepared to replace some seals, even though it is only 4 years old.
I had a new (2 years!) Delta act up on me. Put in a new seal set, and
used silicon grease to lube it. No problems now, either with leakage
or rough operation.