The message . com
from "mjbarnard" contains these words:

Not quite sure what 'tightly' means. It appears a close fit - but the
cone definitely feeds very easily over the bolt.

FWIW the cones on mine are quite a tight fit on the thread. If the leak
is down the thread rather than round the outside of the cones then
silicone sealant on the thread should give an effective seal.

--
Roger Chapman