I read in my manual that my 1981 300d has a capacity of 11 liters of coolant. today when i flushed and replaced it would only take 4 quarts or about 4 liters if i'm correct. I don't understand why. I also changed the thermostat.

Earlier today I finished replaceing a radiator that was cracked. While i was at it i replaced the thermostat. Since the trans fluid leaked out when i changed the radiator i just changed the trans filter. It's all back together with flush and water in it. Trans fluid replaced. I only ran it for a minute so far and the thermostat gage hasn't moved. My son, whose car it is, said something about the thermoustat gage not working. Can either of you for see a problem that would cause the thermostat not to register.

I'm pretty sure the stat went in correctly but i'll check. A minute or 2 after i started it a second time to run the flush through the stat began to jump back and forth eratically. After 10 minutes of idle, while flushing, the water was only warm when I drained it out the drain cock. On the second fill, with just water it ran 10 min, again the with the heater on max, the stat fluctuated at around the 120 mark. When i drained it the water was not verry hot. At least not when it dripped on my hand.
I got what i think were very good directions from the diesel giant. Well it will have to sit until i can get back to it next wed. Thanks. If you have any further guidance please, if you have time let me know.

I just read that there is a venting screw on the stat housing. Is that used to assist in draining or for removing traped air when refilling. I hear that there are also ?sending wires? that could have become disconnected. Does anyone know what they do or where they are so i can check this out.

I surely thought it would much more simple than this. RAY M