Date Dode on Master Cylinder - Julian or Calendar Date??

[Clark E.]

Sorry for dragging out this discussion. Recent threads indicate the casting date on the "date tag" is a Julian date. One thread referred to an article in the Spring 1991 NCRS Restorer that quotes the the guy who produced these tags at the Tonawanda foundry who wrote the first # was the month, the second and possibly third # was the date of the month and the fourth # was the year which could explain why some members are only able to find three #'s and some none at all. Date tags were "not an exact science or a high priority in the foundry". Corvette Stainless Steel Brakes uses a Julian date they will cast for an additional $50. I just want to get it right the first time. Thanks...Clark

[Edward J.]

Re: Date Dode on Master Cylinder - Julian or Calendar Date??

Clark, I believe that the date codes where hand stamped onto the front fitting of the master cylinder and was very small. and is a Julian date code.

[Alan S.]

Re: Date Dode on Master Cylinder - Julian or Calendar Date??

Hi Clark,
The master cylinder on my mid-January 1971 built 71 with standard brakes has a stamp reading 0338. It looks as though the 4 digits could have been stamped by just holding the 4 dies in hand since they don't line up.
Regards,
Alan

[Clark E.]

Re: Date Dode on Master Cylinder - Julian or Calendar Date??

Hi again Alan and thanks Edward... Guess I should have been more specific. I understand there are potentially two dates on the master cylinder we're discussing. One is the "machining date" of the cylinder that appears to be a stamped series of numbers (Julian) just above the front line fitting as you have pointed out. The second is the "casting date" that appears just to the left of the rear bleeder and just below the upside down "mold code" (D-1 to 11) on what the Restorer article referred to as the "date tab". The tab has a screw head on each side (supposedly the type of screw denotes the shift at the plant) and was part of the casting mold. The numbers were changed daily. The article indicated the numbers represented the month, day and year (today would be 1082). This does not appear to be a Julian date.

There isn't a reference to the "casting date" in the JM and it only mentions (page 75) a date code stamped on the front line fitting surface of late '72's. Is it safe to assume the date(s) aren't judged?...Clark

[Edward J.]

Re: Date Dode on Master Cylinder - Julian or Calendar Date??

Clark, I think the date on the front fitting is a judged item, If it can be seen or read. along with the casting part no. I believe the judges have enough to do just trying to read the date and along with other items, there is only so many hours to do these tasks. Alan maybe able to add to this as he is a seasoned judge.

[Chris H.]

Re: Date Dode on Master Cylinder - Julian or Calendar Date??

Clark, attached is a photo of my 69's master cylinder Julian date. Hard to see but it's "3038", 303rd day of 008 (5).jpg1968, which is appropriate for my car, #10255. Chris

[Alan S.]

Re: Date Dode on Master Cylinder - Julian or Calendar Date??

Hi Clark,
I just read the article in the RESTORER.
Now I'm confused. For my car's master cylinder... 1 (January), 4 (Fourth day), are good, but then a '9'?? I'd expect to see a '1'. It is the master that was in the car when it left St.Louis.
So???
Regards,
Alan

[Edward J.]

Re: Date Dode on Master Cylinder - Julian or Calendar Date??

Alan, maybe that was the casting date it was made, who knows how many where made at a time back when they were casted. As the master cylinders maybe be the same from 68/73 with the exception of power and Non Power part no.s ?

[Clark E.]

Re: Date Dode on Master Cylinder - Julian or Calendar Date??

Thanks Alan..."Confusion" loves company. Edward's point is well taken. Who knows if your cylinder's batch sat in the Tonawanda Foundry behind a stack of pallets for over a year. Also, the guy who was the foundry pattern maker in the Restorer article freely admitted he wasn't always focused on accuracy (something about being 22 and more concerned with girls). After re-reading the article, the first digit was a letter (not a number) denoting the month so your "1" may actually be an "L" for December. Isn't this fun?? Best...Clark

[Alan S.]

Re: Date Dode on Master Cylinder - Julian or Calendar Date??

Hi Clark,
You're right! I need to tighten up on my 'reading for comprehension' skills. Missed the letter/month point completely.
Regards,
Alan

[Clark E.]

Re: Date Dode on Master Cylinder - Julian or Calendar Date??

Hi Alan...Glad I could finally "contribute" something to the cause. You and the Forum have been invaluable to my restoration efforts. Best Regards...Clark