Steve,
You have not harmed your cooling with the vinegar flush. Vinegar is a fairly weak solution of acetic acid(4-5 percent).Acids have no effect on fats(grease).To do a good job of cleaning your cooling system, you need to use a degreaser first, followed by a citric acid flush. The degreaser removes the oils and grease deposits allowing the acid to do its job.I did my 1982 300D-turbo last summer, and I can say the stuff does a good job. You can get the citric acid from your local super market. Look in the home canning srction. Or get it from your local MB dealer.Part No.000 989 10 25. The degreaser No.is 001 986 21 71.
Bill Lewallen Lexington,Ky.