The 98-02 water inlet P/N 16032-50070, is no longer sold. The leaking cap bolt on to it, with hose nipple, never was sold separately.
Replacement is the Newer water inlet is P/N 16032-50110. www.partsouq.com is excellent diagrams, P/N and pictures. This first number is original P/N. Click on it and scroll for update. USA P/N something will update again.
You can use FIPG 1282B, see if seals.
Make a gaskets
Or update waster inlet.