Good morning, being new to the forum and also to the Mercedes world, I have a question for you, I just replaced the water pump in my 1980 450sl pressure tested the cooling system to 14 psi and noticed a leak in what appears to be the heater control valve. The valve in question is located in the right hand corner of the engine compartment next to the firewall, it has heater hoses,vacumme lines and wires going to it, looks very expensive.does anyone know exactly what it is called and where can I get one. The leak is not a loose hose and appears to be coming from the valve body itself. Thanks in advance for any help. Troy