Coolant leak - can someone tell me what this is?

[RichardTaylor]

We have a small coolant leak on our Yanmar 29hp, and I beleive I have found the source. Below is a picture of a "piece of plastic" in the coolant to calorifier hose which is wet. I have tightened the hose clips but feel it is the "piece of plastic" which is the problem?

Can anyone tell me what this "piece of plastic" is and what it's purpose is?

Many thanks
Richard

 

[Giblets]

Looks like a tap of some description or maybe even an air vent. Is it possible that the plastic has been damaged by over enthusiastic tightening of the jubilee clips?

If an air vent then it is possible there may be a washer under the knurled knob that has failed.

 

[VicS]

Looks like a tap of some description. Is it possible that the plastic has been damaged by over enthusiastic tightening of the jubilee clips?

I think its an air vent. used to vent air from the system when filling. A clue is that it says "keep tight" on it.

I assume we are more or less looking down on it and that it is in a high spot in the system.

The hose clips may have been overtightened leading to leaks due to distortion or even damage to the ends where the hoses are fitted

 

[Hadenough]

A clue is that it says "keep tight" on it.

"Eyes like a burglars dog" as me dad used to say!

 

[VicS]

"Eyes like a burglars dog" as me dad used to say!

Not sure what the rest of it says "antifreeze coolant" maybe

 

[RichardTaylor]

That would make sense, I had cropped the picture so below is the actual location (high up) in the coolant circuit.