Welcome to the site !!
Sorry for late reply , I just noticed this post
From what I see on the parts fiche , it is all one unit ... I have not had any incidents like that with my 20 , as I don't trail ride it , I have a X for that , so no help there , it looks to be a $80 water pump cover with the fittings as a unit , so they are not expecting anyone to take it apart or service it , I am thinking replacement is the only permanent option .... what you could try for now to get you by till you can get a new one , is try to tap the fitting in with a rubber or plastic mallet , to make sure it is as seated as possible , and seal it with a equal part epoxy , I am assuming there is some kind of O-Ring or something that "seals" it down inside , so with the epoxy , it should completely seal the area around the pipe to the cover , I would also scuff up the surface of the pipe right where it goes into the cover to promote adhesion , and use a putty knife or something to force the epoxy down into the gap ...... This will at least buy you some time so you can order a new one , because with shipping the way it is for OEM stuff , it could be a bit , at least this way you can ride till it arrives ....