Slow coolant leak at radiator drain plug

[nyutonka]

Hi guys,

I seem to have a slow coolant leak at the radiator drain plug. It's slowly dripping down on the whole radiator, but the leak itself seems only to be directly at the drain plug.
Do you think replacing the drain plug could solve this issue, or should I prepare myself for a more thorough investigation?

 

[lfhoward]

You could try some of that Teflon plumbers tape on the drain plug to make sure it seals.

From what I’ve read over the years about Liberty radiators, they tend to leak at the upper corners. If not the drain plug, see if a leak is just ending up there by gravity.

 

[turblediesel]

If that's on top it's an air bleed or fill hole. I think there's an o-ring that seals whether it's a bleed or drain, or fill. Should thread out without much turning which opens the valve. Pull out more and turn and it should come out completely somehow. Clean it up and maybe replace the o-ring.

I'm basing this on rusty memory and somebody else's post.

Alternative darker scenario is a bad headgasket overpressurizing the cooling system. With a cold engine open the pressure cap on the coolant tank and close it. Run the engine for a minute or two and shut it off. Open the pressure cap and listen for a release of pressure... bad news if it burps. It's a CRD thing.

 

[turblediesel]

UPDATE

I looked at mine. It's just an air bleed used when changing coolant. It only turns 180° to open completely and the o-ring is easily accessible.