Good morning

I hope someone can help with an annoying problem.
I have a Yanmar 1GM10 inboard on my small sailing boat. It runs really well.
Recently I had it serviced, oil changed etc. including replacing the
impeller.

It has had a salt water leak for many years before I owned the boat. I have
only owned the vessel for 2 years.

The salt water is coming through the impeller housing, and dripping from the
designed hole between the impeller and the engine. I sense this is where
the engine shaft goes through to drive the impeller. It is not coming
from a gasket - that would be too easy! I did not see what the seal is like
where the shaft enters the area of the impeller. Is there a replaceable
seal there? Will it need a new impeller housing? I hope not. No gaskets
are leaking at all. He put on a new gasket when he replaced the impeller.

I would appreciate any information you may have in this regard.

Many thanks