Autozen: could you please tell me more about the “bad” radiators that you have gotten from Behr in the past? What was wrong with them? (This won’t matter in my case, because the radiator is functioning properly, but I’m curious.) I am aware of the distance/field of view aspects of the infrared thermometer. This one has a distance to spot ratio of 8:1, and I *do* use it close up. There is also parallax error to deal with if the laser is used for aiming.

As far as adding more water? I’m not sure what you mean – the system is full. If you are referring to the antifreeze/water ratio, it is 40% antifreeze and 60% water, so I am not going to dilute if further. Perhaps you can elaborate further on your 300SD example. Why would you need to keep adding water unless you were losing it somehow?


Chowpit: When I fill the system, I use the upper radiator hose – I disconnect the radiator end of it and fill up the block & head this way. It is the same thing – it is the high point in the system. I can see on the service CD that the earlier diesels had a different configuration. Plus, this later system is supposed to be self-venting.

The thermo switch in the top does NOT control the auxiliary fan on this model (1984 300D California version). I know that every other MBZ I have (and had) did have a 212 switch where you mentioned. The 1979 240D wiring diagram that I just looked at has a 212 switch also. I don’t know what they were thinking at the factory when they decided to eliminate this from the system.

Thanks Guys

RTH