PC, the slot is to let the drips out! What has happened is the shaft seal
on your pump has failed, and needs to be replaced. it isn't a difficult job, and if you source the replacement seal from a normal bearing supply house it will only cost a couple of bucks. From yanmar
, a lot more!
I could describe the process, but maineSail has in his very good website done it with pictures and good advice. Go and have a look, and if you have further questions, come on back.
Oh... there have been many discussions about this sort of problem right here on CF, so a quick search would benefit you as well. Use the "custom Google
search" feature under the general search tab at the top of the page...