Hi Dennis, 

Sounds right. 

It seems to seep so I think I need a new copper gasket. 

Thanks for this info.

10 millimeter out side diameter ?

Eric 

> On Apr 16, 2024, at 12:46 PM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> 
> On the 2.1L cooling system there was a hose connection for the oil cooler return. Some pumps have a non removable hose bib, yours has a threaded hole for either a hose bib or plug. The plug usually has a gasket or o-ring to seal it. A 10mm copper or aluminum seal ring should work well. 
> 
> Dennis
> 
> 
> -----Original Message-----
> From: Vanagon Mailing List <vanagon@gerry.vanagon.com> On Behalf Of Eric Caron
> Sent: Tuesday, April 16, 2024 9:32 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Mystery plug on Water pump.
> 
> Hi folks, 
> 
>        My water pump has a plug with a hex fitting.  It seems to be seek\ping coolant.  
> 
> Any tips on how to seal that better?  And, what that opening is for?
> 
> Eric Caron 
> 85 GL 2.3 Waterboxer