67 68 Master Cylinder Date Codes

[Dan M.]

My original DC master cylinder is long gone. In trying to replace it with a correct casting MC, I also want to get the date code right if possible.

A fellow member here has one for sale. I am not clear on the date coding and reserached it in the prior forum posts with limited success. It appears 67 DC m.cylinders were not coded, but 68's were.

What was the date coding key for 67 68 DC master cylinders? It appears to be a letter followed by one or two numbers. Is the letter the month (A=Jan, B=Feb, etc) and the number the day of the month or is the year one of the two numbers? Please help.

[Joe L.]

Re: 67 68 Master Cylinder Date Codes

My original DC master cylinder is long gone. In trying to replace it with a correct casting MC, I also want to get the date code right if possible.

A fellow member here has one for sale. I am not clear on the date coding and reserached it in the prior forum posts with limited success. It appears 67 DC m.cylinders were not coded, but 68's were.

What was the date coding key for 67 68 DC master cylinders? It appears to be a letter followed by one or two numbers. Is the letter the month (A=Jan, B=Feb, etc) and the number the day of the month or is the year one of the two numbers? Please help.

Dan------


I believe the consensus is that 1967 master cylinders were not date-coded. 1969 master cylinders were date-coded with a julian series in which the first digit represented the last digit of the year and the following 3 digits represented the consecutive day of the year (e.g. "9059"= February 28, 1969).

Julian date coding was common for Delco-Moraine manufactured parts. I don't see why 1968 would have used a different system, but I suppose it's possible it did. Some 1968 owner will need to confirm.

[Daniel S.]

Re: 67 68 Master Cylinder Date Codes

Per the Judging Guide..The front brake line fitting surface of your '68 master cylinder should be stamped with a date code. The code is a Julian Date.

[Brian W.]

Re: 67 68 Master Cylinder Date Codes

My early (dec) master cylinder, no date code.

[Brian W.]

Re: 67 68 Master Cylinder Date Codes

I forgot to mention early 68.

[Dan M.]

Re: 67 68 Master Cylinder Date Codes

So I have a correct non-power m/c in hand but it has a 3 digit date code. All numbers, no letters. Any idea how to decipher this date code?

Number is 218.

[Terry M.]

Re: 67 68 Master Cylinder Date Codes

I was going to stay out of this, but now that you have posted that date Dan I will tell y'all my story.

The original master cylinder on my 1970 (I know it is the original one because I bought the car new) has a single number 1 stamped for the date.

Many years ago, when we still had real swap meets, I saw a vendor selling one with that date stamp at the McLean County Fair Grounds (now you know how long ago that was) for $400 with the sign "RARE" on it. I didn't bother to ask him what he thought made it rare because I didn't think it would be a fruitful conversation. Other master cylinder cores were selling for $20 to $25 at the time.

And now you know why I don't judge dates on the master cylinders. Until we know a lot more about these things than we have found out in the last 30 years, I am out of that race.

[Grant W.]

Re: 67 68 Master Cylinder Date Codes

So I have a correct non-power m/c in hand but it has a 3 digit date code. All numbers, no letters. Any idea how to decipher this date code?

Number is 218.

Hi Dan
I think it is 21st day of 1968. I have others are 1338, 958 etc.

Hope this helps.
Grant

[Dan M.]

Re: 67 68 Master Cylinder Date Codes

Thanks Grant. It does.