350 SDL Coolant Replacement Question?
 

I want to replace the radiator/engine coolant in my 1991 350 SDL and have a couple of questions:

1.What is the proper Mercedes type of anti-freeze to get?

2 .How much anti-freeze do I need?

3. Where exactly are the drain plugs that I need to use? Is it the blue plug under the radiator, are there block drains too? If so where are they?

4. Should I "back-flush" the system? If so what do I need for this?


Thank you.

Yes, there is the drain (blue) plug in the radiator, plus there should be a block drain on the engine too.

For antifreez, you have two choices, either MB coolant from the dealer, or Zerex G-05 (My choice). These are the only two certified for use in MB diesels. Don't cheap out on this, broken radiator parts are what you get from other stuff, and it just isn't worth it to shave $30 (if that) every 150,000 miles.......

Don't forget distilled or deionized water.