955 water pump housing and front engine gear assemblies

The weep hole in the water pump is there to tell you the seal is leaking.
Water in the front case/timing gears didn't come from the water pump.
Go easy on that water pump housing, they are unique to the 955 and are hard to find replacements.
I don't know what plug you are referring to by the injection pump. Block drain? Oil level ??

The seal is leaking, referring to the seal between in the inner water pump housing and block? Does the weep hole go through the inner pump housing toward the block? Is that where it drains to tell you there is a leak? There is a small plug, flat head screw head on the front gear cover, right hand side. When removed you can see the gear for the fuel pump.

The weep hole indicates there is leakage past the impeller shaft seal coming from the water side past the seal and out the external weep hole. Nothing to do with the block. Not a source for water in the timing gears.

The weep hole I'm referring to is in the back side housing that's bolted to the block and fuel filter housing, and oil cooler. It's not on the housing that holds the impeller, and shaft.

Is that something you can get a picture of? I'm not aware of any other weep hole besides the one for the water pump.

Next time I'm down in the country, I'll take pictures.

Thought I would add a comment here. Recently found water in the oil of our D5 3306. Figured we had bad liner seals but when we removed the oil sump there was coolant running out of the front gear case.. Turned out the weep hole on the water pump was plugged and coolant was being forced into the gear case. I know the 3306 and 3304 are basically the same engine except for number of cylinders. Not sure about any variations in the 955 though.
I am not aware of another weep hole on the back side of water pump. Curious to see pictures.

Hello
Looking at comments so far, is this 955 serial number 12A------
Therefore powered by Caterpillar D315 engine.
If so then the water pump is belt driven and this hole could be
a vent when filling cooling system.
Best regards

Yes it's a 12A, the weep hole I'm referring to is on the back half of water pump housing. I pulled the outer housing off that had the water pump and shaft, impeller assembly. The back half still attached to block, just below the circular impression where the impeller would fit, I noticed a small hole leaking water. I was able to spray some brake cleaners up in the hole with the tube that comes with the can. I flushed it out, but curios as to where it might lead, or if there's a crack.