Can You Identify The Leak?

[Ian]

This was received from member Paul Kelly. He has a 1995 4WD diesel Bongo.

I finally got around to changing the timing belt on the van thanks for getting the parts to me. I am looking for a bit of information that you might be able to help me with. While I was under the van changing the belt I found a leak on the right hand side under the engine. I’m not sure what the unit is and if there is an o ring or gasket causing the leak. I was hoping you might have seen or heard of this problem before. I have attached a photo with a screw driver pointing to where the leak is.
I would be very grateful if you can help me with this.
Do I need to replace the unit, replace an o-ring/gasket or re-seal it?
I don’t want to remove the unit until I have some idea of the fix, as I know bleeding the cooling system is a chore.

[teenmal]

Is it Water Oil or Whisky ?