Yes, I know about cleaning without removing. But for $239 shipped I decided just to replace it and be done with it. It's had a good, long life. Some folks had the experience of cleaning it only to have it act up again within a few weeks.

Even though it looks like a pretty straightforward job, there doesn't seem to be much room to work in that little area. Any tips, suggestions? This is helpful: http://www.pelicanparts.com/techarticles/Mercedes-Benz/19-WATER-Cleaning_Heater_Control_Valve/19-WATER-Cleaning_Heater_Control_Valve.htm

I can clamp the hoses and assume I won't lose too much coolant from the housing.

__________________
14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 159k miles
06 E320 CDI "Rutherford", Black on Tan, 179k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 145k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 77k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife