@Den Hewitt wrote:
There is no seal. The hole is to take the split pin for the castellated nut “D” in the attached photo.
There is an article of Water Pump refurbishment in Vol 10 1985/86 Issue 4 Sep of Floating Power available to members only on the TOC website
Thanks Den. Unfortunately the file for that issue seems to be damaged as I get an error message when I try to open it. Other issues are working for me.