Mercruiser Water Pump Base

[dpoff]

I am replacing my water pump on a `74 merc 165 in-line 6.
Can anyone tell me what the groove that is cut along the face of water pump base is for?
Is this to cool the oil seal?

 

[muc]

Re: Mercruiser Water Pump Base

It allows water to drain out after use. One of reasons gasket sealer isn't recommended.
Good Luck Muc