What purpose of this part

[olegk]

Hi,
Can someone tell me what is this? I have no idea what purpose of it. But definitely this is only place the water can come into lower unit. Did pressure test with the hole blocked - no bubbles.
Can I block it permanently?

Picture for drive shaft seal housing underneath of water pump

 

[Joe Reeves]

Re: What purpose of this part

That is a pressure vent that would allow gearcase pressure to escape. Obviously it is faulty. I'd suggest that you seal it thoroughly with something like JB Weld or replace that bearing/seal housing.