C-3 Master cylinder Dating

[Bill Lloyd #33481]

Where is the date code on a 1972 master cylinder (509 DC)? Was it a cast in number or a tag?

Bill

[Joe L.]

Re: C-3 Master cylinder Dating

Bill-----

It was neither a cast number nor a tag. The date code, if one is present at all, is stamped into the flat machined surface surrounding the front brake line fitting. It will be very small, stamped characters in a julian date code format of four digits for sequential day of the year and last digit of the year. I've forgotten whether the year comes first or last in the series.

[John H.]

Re: C-3 Master cylinder Dating

Some (not all) 509's had a very small julian date stamped on the spotface-machined area surrounding the front fitting port (mine doesn't).

[Gary S.]

Re: C-3 Master cylinder Dating

Joe, my original MC off of my November 4th built 72 has a THREE digit julian date. As I recall, typical julian dates do not include the year do they?

Gary

[Joe L.]

Re: C-3 Master cylinder Dating

Gary-----

Some do; some don't. The original master cylinder on my 69 has 4 digits with the year. I don't recall if the "9" was first or last in the series.

[Terry M.]

Re: C-3 Master cylinder Dating

I believe, but have NO documentation to support that belief, that those master cylinders that have three numbers can be properly read by adding a leading zero. However, I have seen some master cylinders that seem to have a number that makes no sense. Ever see one with just a single number one? I have, and I have no idea how to determine that date.