What is this leaking on my 190D?

[Highfiddleedee]

Hi
Today my 190 sprung a leak! After some investigation I discovered that this creamy coloured plastic bit is the culprit. I assume it is part of the heating plumbing, as it is high up above the engine just behind the engine bay bulkhead. Could someone tell me what it is as I imagine I will need to order a new one, assuming of course that they are not a simple DIY fix. As always your help is much appreciated.

Norman

 

[Dieselman]

Heater control valve.

 

[grober]

Vacuum operated- get a new one only £15-£20. I think the part no is A0008305784 but best to check via the chassis number at your friendly local MB dealer.