Coolant leak from joint on top of thermostat

[digiboy]

Hi all,

Just found that I'm loosing coolant, a fair amount was under the vehicle after returning from a couple of days away.

(It's a TD4 commercial on a 52 plate)

After removing the sump guard and following the trail back, it's coming from what I think must be the thermostat housing.

In particular the joint between the metal pipe that goes round the back of the engine and then connects via a rubber hose to the header tank, which is bolted by one stud to a plastic housing on top of the water pump.

In my Haynes manual it shows a unit that looks nothing like the one I have (what a surprise) but does indicate that there is an 'O' ring in there, which is logical if it's metal to plastic.

Before I scrape what is left of the skin on my knuckles off - can anyone tell me if I have to replace the whole of the thermostat to cure it or maybe the 'O' ring just fails? Can't find my Landy CD at the mo.

Phil.