Question about draining radiator
 

Folks, I just got my AC fixed after being without all summer down here in toasty Houston, TX. I'd like to flush out my radiator tomorrow, and was wondering if there was any kind of priming or bleeding in the coolant system in my 1983 300D? I distinctly remember on my old 1979 240D I had to bleed the coolant system by unscrewing a bolt until antifreeze came out. Is there anything like that on the 300D, or can I just empty out the radiator, flush it gently with water, then fill it back up again? Thanks so much in advance for your help!

You will have to burp the system by doing the following...

1)Park the car pointed uphill or put it on ramps

2) fill the block by removing the hose from the top of the radiator and filling it with water until it overflows then reattach it.

3) Fill the expansion tank and start the car. Get it up to normal temperature

4) Turn the defroster on

5) Rev the engine to about 3000RPM a few times the air should come out of the system.


If you are going to flush the system make sure you drain the engine block via the block drain. Do some searches on Citric Acid Flush to see comprehensive instructions.

Good luck!

Thanks so much, folks, for the help and advice. I did replace the antifreeze and added a bottle of water wetter to boot.
A word of warning: I replaced my leaking overflow tank as well, and the new one had a hole that my other one did not! The counter clerk at the MB dealership gave it to me, and I had the foresight to compare it to the one on the car, as something didn't look right. I brought the new one back in to the parts dept. and began telling the clerks that I thought that the one they had sold me was for a different year. The other parts clerk assured me that it was for the W123s, but that the other clerk had failed to give me a little kit to plug up the extra hole. Once we got that in ( a little work) we were good to go. Thanks so much again for your help and advice!