[QUOTE=Oldblue;826846]Never heard of a weep hole in the tank just on the water pump

Anyone have any intel on this hole? It looks like it’s possibly there to prevent coolant from reaching up the filler neck

 

Maybe pan back a bit, give some context to where it is on the reservoir.

 

How about to hold the hose from flopping around.

 

 

nope. That’s a slot in this case.

 

For some other vehicle that uses it?

 

it’s pretty small. And the hole goes straight into the tank, not out the back side. I’m not aware of any other vehicle that uses this tank. I’ve checked since fitment websites and come up with nothing.

 

Well, then it is a weep hole. Air needs somewhere to go when the fluid goes in and the lid could become air tight under some circumstances.
The only time fluid would get that high is in a boil over. It should stay in the bottom few inches of the bottle.

 

I think what the OP was trying to ask way back when (not that it matters to them now, but might for folks brought to the thread via search engine) was if the cooling system is pressurized, why is there a small hole near the top of the recovery tank… and what is it’s purpose?

I think we’ve probably narrowed it down to being an overflow/air outlet/inlet. But being that it’s so important to burp the cooling system to remove air for the proper flow of coolant… I think the OP was confused as to why the recovery tank (being part of the cooling system) wouldn’t also need to be under pressure.

 

Cooling system IS pressurized, the recovery tanks are not..