Water pump leaking on top.. what is this?
 

1992 Sc300 Auto. Water pump is leaking on top from underneath the circled cap. I have not yet removed the cap. Just curious as to what this is (circled below) I haven't been able to really find any pictures of information about it. Any info would be appreciated.

https://cimg4.ibsrv.net/gimg/www.clu...b4aa38abd1.png

also seen in this picture

https://cimg1.ibsrv.net/gimg/www.clu...41f57fe80f.jpg

can anybody chime in?

My only thought is that it's similar to a "weep hole" on older style water pumps. My newer water pump does not have that so I can't compare personally. However, older water pumps would start leaking out of a similar opening as they'd start to fail. I can't say exactly how/why. Someone please chime in and correct me if needed. However, I would say that's more than likely the sign of a needed replacement for one reason or another.