Quote:


6. the MA article states that all MCs up through 74 were painted black. I believe that is NOT TRUE.


Actually the article says that "a few NOS examples from the early '70's have been observed with the dark gray phosphate coating". In addition the photograph on page 85 shows an NOS example that is phospate gray coating.
Based on the NOS samples I had at the time I wrote the article, I was not certain, but I have since come to the opinion that phospate gray is correct for most of the new master cylinders introduced for the '71 model year. That is not always true though, every manual disc brake master cylinder for '71 up I ever saw was painted black.
I continue to study master cylinders and on rare occasion have come up with something that contridicts what I wrote. I pass this info on when I find it. For example I wrote in the article that late '60's drum brake master cylinders were natural cast iron finish. After the article came out I found some master cylinders off of original cars and some early date coded NOS examples that were ecoated black, so I now believe that is correct for that master cylinder. That goes against what some want to believe, but the evidence is strong that the black ecoating is correct.
Just to confuse the issue further on the early '70's master cylinders, here are a couple NOS'71 up disc brake master cylinders that are black. The top one is painted black, the lower one is ecoated black prior to machining during manufacture, with a gold plated cap. Both have late '70's date codes.
You can see that based on studying NOS samples you find contridictory information!!

4512278-black71upmcs.jpg (35 downloads)