Date code for original '64 master cylinder mystery

[Garry B.]

I have located a master cylinder for my '64 with PS and it has the part number cast in the bottom and the 7/8 at the front of the unit, but there doesn't appear to be a date. Did all of them come with dates? Were there service units available later on that would have been configured this way? Thanks.

[Garry B.]

Re: Date code for original '64 master cylinder mystery

With Don Hooper's help I believe we have solved the mystery. Thanks Don.

[Leif A.]

Re: Date code for original '64 master cylinder mystery

Do you mind sharing the resolution with the rest of us?

[Garry B.]

Re: Date code for original '64 master cylinder mystery

Leif, I was looking for the date location near the 7/8 mark at the front of the unit based on this text from the JM version 6,

Any thoughts on how to determine the date on this one? Leif, I hope that answers your question.
Garry

[Edward J.]

Re: Date code for original '64 master cylinder mystery

Garry, the number 307 is 307th day of 64.

[Patrick C.]

Re: Date code for original '64 master cylinder mystery

How do we tell it is the 307th day of 64? Would there be some other difference for the 307th day of ‘63?

[Garry B.]

Re: Date code for original '64 master cylinder mystery

Patrick, that's my question as well. Another thought is if you use the Julian Calendar and put in 3 0 7 you get November 3th, in 1963 or November 4th in 1964, but I couldn't tell you if that is what it is either. Again, how do you know what year?

One thing that is clear is what text is in the 6th edition of the JM is grossly incorrect based on what we are finding.

[Patrick C.]

Re: Date code for original '64 master cylinder mystery

My ‘64 was judged three weeks ago and no deducts on the master cylinder. I will dig up the pictures later tonight and post them. Mine is a January 64 build date.

[Patrick C.]

Re: Date code for original '64 master cylinder mystery



Im not sure this is helpful. Looks like mine has a date of 255 with a 3 underneath. Sorry this is the best picture I could find. Still not sure how you tell if its manufactured in 1963 or 1964.

[Edward J.]

Re: Date code for original '64 master cylinder mystery

Guys, its my understanding that the Julian date is used without a year, that's how the JM reads. unlike 63 master cylinder does use a year.

[Garry B.]

Re: Date code for original '64 master cylinder mystery

Ed, I think you are right. They must have changed the JM since the fifth edition because it reads, "The casting date is in a MDDY format (Example:B 18 4= Feb. 18, 1964)". I know this is an older version of the JM, but thought for sure after five iterations of the JM this would have been caught and correct. This is what started my inquiry in the first place. I have checked mine and the part number is there but I can't read the date. It was restored at one time and the casting is just too tough to see. Thanks for the pic Patrick.

[Alan D.]

Re: Date code for original '64 master cylinder mystery

My original is dated 337 with a "4" under neath it. It is a J65 power system, been through all the numbers of each wheel all good. Did find one wheel cylinder which (I knew) got replaced. Owner car since Aug 67.
May not help but can be used as a baseline. sorry about poor photo's

[Garry B.]

Re: Date code for original '64 master cylinder mystery

Patrick, amazingly I was able to stand on my head and read my master cylinder and it was manufactured the same 255th day as yours. There is a number under it which I believe is a 3, but can't really see it well enough to be sure.