Water pump question

[Roald]

I’m swapping mine as it has started to leak.

The new one has what appears to be a plug in the circular hole. But the one coming off doesn’t. Haven’t seen a video yet address this. Does the plug stay in?

 

[Roald]

Never mind. I am an idiot

 

[golfRdaddy]

yup.. thats just a protection cover.

 

[Roald]

So it turns out, the old is just still in the open position. And the new one is closed.
But the tolerance are pretty solid given it seals out water and it was just hard to see until I took the old one apart and saw the rotating mech in there.