Water Pump "weep" hole

I just noticed my new 8-vane small block aluminum water pump has the weep hole plugged from the factory (unless it is some kind of insect cocoon).

IMO....the purpose of the weep hole is to allow minor seepage/weeping of coolant ftom contaminating the pump's bearings. The seal is a simple cartridge type mechanical seal....a ceramic stationary half (usually) sealed to the housing with an O-ring verses a carbon faced rotary half (usually) sealed to the shaft with and driven by an O-ring, with a small compression spring to keep the faces in contact. Minor leakage over time may occur but at the first appearance of coolant at the weep hole, is an indication the seal is on the verge of failure. Opinion....clean out the weep hole.
BOB RENTON

Has the pump been sitting on a shelf for awhile.....and not in a box or sitting on an engine? If so, I suspect a dirt dauber.

It was sitting out of the box, yes. You mean someone is taking up residence inside?

The reason for the hole is to let you know when the seal goes bad. It's located in front of the seal so when coolant gets past the seal it runs out the hole. Time for a new pump.

Yours is clogged with something. Might be corrosion.

Dibbons said:

It was sitting out of the box, yes. You mean someone is taking up residence inside?

Click to expand...

LOL! Yes. Dirt dauber/mud dauber.....I deal with those dang things all the freaking time from early spring to the late fall!! https://en.wikipedia.org/wiki/Mud_dauber
Killed five of them trying to get out of the shop just this week! They come in and do their deed and when the newbies hatch out, they try to get out of the shop. Usually, I'm in the shop pretty early in the morning and will leave the front walk through door open but the glass storm door is closed and will usually find 1 or 2 trying to get out within an hour or so but they end up dead Early in the year when the temps are still fairly low, I won't open the big doors and then I can get them. The 'newbies' will return to make more offspring and it just keeps getting worse so it's a never ending battle if any of the newbies can get out.