'64 PB Master Cylinder Date Coding

[James W.]

Hello,

What is the proper date coding for a 1964 Corvette? I read in the judging manual that it is suposed to be in the month, day, year format. Should the date be previous to the cars build date? The master cylinder that I'm interested in buying has the correct Delco part number of 5464264 but the numbers found on it are 189??? Is the date suppsoed to be a Junian date???

Thanks,

James West
Omaha, NE.

[Philip Whitaker Member #2024]

Re: '64 PB Master Cylinder Date Coding

James,

I believe the JM is wrong. If you search the archives you may be able to find more information on this subject. All of the dates I have seen on the castings are Julian dates. There should be a single digit under the 189 to signify the year.
The date should precede the cars build date. I'm not certain how much it can precede the cars build date, but I think the JM allows for up to six months on most dates. The M/C for the power brake cars carry the same casting number as the non-P/B master cylinders. The power brake M/C have a bleeder on the side. Be sure you buy the correct one for your application.

Phil

[Scott Butville]

Re: '64 PB Master Cylinder Date Coding

Based on the info in the archives, I looked at several before purchasing one. All had three digit Julian dates, none had the TM&JG specified format. The one I bought has 104 which I believe is either the 104th day of 1963 or 64. I have no idea how to decide which year applies. In my case, September '63 production, I'd like to think its early April '63 which would be correct. You'll see in the archives that many believe the TM&JG is not correct.

[Philip Whitaker Member #2024]

Re: '64 PB Master Cylinder Date Coding

Scott,

Doesn't your M/C have a single digit below the '104'? Mine is not original to my car but does have a number below the Julian date. It looks as though the Julian date is fastened into the mold with screws and that the slot type in the screw head may bear some signifigance as to the shift. Mine has '+ 37 -', and the numbers are raised. Then directly under that is indented ' 3 '. I take this to mean the 37th day of 1963. Most of the ones that I see on ebay appear to have a number under the Julian date. The pictures are never clear enough to tell for sure. I bought mine before I even knew that they were date coded. Probably 15 years ago. I think that it's way to early for my December 1963 built car. When and if I ever have the car judged, if I miss Top Flight by 1 or 2 points, I might consider looking for one with a closer date. Or I might skillfully apply some JB weld to make the number 2 in front of the 37. LOL

[Scott Butville]

Re: '64 PB Master Cylinder Date Coding

Philip, Without going through the archives, I think I remember the conclusion was that the number to which you are referring is the cavity number of the mold, not the year. I wonder if anyone on this board has seen one with a number other than 3 or 4. If not, I would think you are correct. Mine is out being re-sleeved so I cannot check.

[James W.]

Re: '64 PB Master Cylinder Date Coding

Phil and Scott,

The master cylinder I'm looking at has a julian date of 189 and the number 2 below Julian date. How is that read as far as a "date" is concerned? My car is a mid January 1964 build date? I've been looking for a correct PB master cylinder for long time and don't want to let another one slip away.

Thanks,

James West

[Philip Whitaker Member #2024]

Re: '64 PB Master Cylinder Date Coding

James,

If the 2 does actually indicate the year of the casting, as I believe it does, then the master cylinder you are looking at came off of a 63 passenger car with power brakes or metalic linings. According to my 1964 Chevrolet parts manual the same cylinder was used on 63 and 64 passenger cars with production P/B or metalic linings. I've only seen this casting with a 2,3, or 4 in that location. I'm not sure what 65s with drum brakes used. I do know that 63 Corvettes used an entirelly diferent M/C. According to the 1979 Chevrolet parts book the M/C for 65 and 66 Corvettes with drum brakes and no power assist both used this same cylinder. How ever, I don't believe that there are any 66 Corvettes so equipped.

[James W.]

Re: '64 PB Master Cylinder Date Coding

Phil,

Sound like I should pass on this one also. I know that the '63 Corvette used a thumb screw master cylinder cover. As for the passenger car PB master cylinder, I don't remember what they looked like. If the number 2 under the Julian date is in fact a 1962 casting date, then it would not be correct, it would work and look correct but not be judged correct for my car's build date.

Looks like I'll keep looking.

James West

[Scott Butville]

Re: '64 PB Master Cylinder Date Coding

Philip,

Not that GM was ever entirely logical, but it would sure seem strange that your info says they had this part available for '63, it was obviously OK for Corvette use since they used it for '64 and yet they chose to make a separate master cylinder for the '63 Corvette. I worked for GM back then and they usually didn't miss those kind of cost savings opportunities. I'm hoping an experienced '64 judge chimes in here somewhere.

[Philip Whitaker Member #2024]

Re: '64 PB Master Cylinder Date Coding

James,

I have an inexpensive parts interchange manual. I looked up the application for the Moraine 7/8 inch bore M/C and it shows 1964 Chevelles and 1965 Corvairs using the same casting. I don't no if it is a fact, but I checked ebay and there is a 62 Corvair M/C that looks like the 63 Corvette M/C. You might start watching Corvair M/Cs on ebay. If it should work out that the castings and dates are those that you are looking for, you'll probably be able to buy it much cheaper than ones listed as a Corvette M/Cs. A trip to the local auto salvage may be what you need. I think that I'll go find all I can gather from the Corvairs and then list them on ebay as Corvette M/C. I should make a killing. LOL

Maybe Joe Lucia can shed more light on other applications. He seems to be the most knowledgable person in the hobby when it comes to identifying GM parts and thier applications. Perhaps if you post the subject line as 'Attn. Joe Lucia' he will help you out.

[James W.]

Re: '64 PB Master Cylinder Date Coding

The master cylinder I'm looking at is on Ebay and advertised as correct for a '64 Corvette. I started asking the seller questions regarding the date codes and what I've told you is the info he supplied to me. So have we decided this master sylinder is in fact NOT correct for a '64 Corvette? It has the correct Delco/Moraine part number but doesn't seem to have the right dates. The price is already over $100. I guess if I'm goig to spend that much money, I'd rather have a correctly "dated" PB master cylinder.

Regards,

James West
Omaha, NE.

[John C.]

Re: '64 PB Master Cylinder Date Coding

One more example:
My 1964 PB equipped coupe has a "37" date with a "3" below it. This would decode as a Feb. 6, 1963 cast MC on a Corvette with a build date of June 22, '64! Just a bit more than 6 months!

[Scott Butville]

Re: '64 PB Master Cylinder Date Coding

James, I paid $102 for mine and it needed to be resleeved. The one you are looking at is the only other one that I have seen on e-bay in the last year with the correct casting number. I called some of the major dealers (Paragon for example) and was quoted $150 for a part needing resleeving. Just like the 2818 carb (as opposed to 2818-1) these things ain't cheap. If you're heading for judging (I am) and have an aftermarket MC with no originality credit (I do) it still might make sense to grab it.

[James W.]

Re: '64 PB Master Cylinder Date Coding

Scott,

Thanks for the info.

James West

[Philip Whitaker Member #2024]

Re: '64 PB Master Cylinder Date Coding

James,

The casting number that you are refering to (5464264) is just that. A casting number. It is not a Chevrolet or Moraine part number. This casting was used to build a variety of different M/Cs for different applications. These final assemblies were given part numbers. It would be impossible to look at a used M/C and tell what it's original part number was. However, I'm fairly certain that if you find a M/C with the correct 'casting number' and the date code that you desire, I think that it will work for you and the judges should be happy.

The seller on ebay is being truthful when he says the 'casting number' is correct for a 64 Corvette. However, given the date code, I don't believe that it left GM on a Corvette.

I don't think you'll have that difficult of a time finding one with the date in the window that you're looking for. The date on mine is probably too early to have left GM on a Corvette. And I paid around $100 for it 15 years ago when I didn't know any better and thought that these M/Cs were rare as hen's teeth. I had to send it out to be sleeved. That's pretty much to be expected with these old castings. I see them on ebay all the time. Like I said, search ebay under 'Corvair master cylinder' or 'Chevrolet master cylinder'. Then query the seller as to the casting numbers and date codes. Corvair stuff just doesn't fetch the big bucks that Corvette stuff does. So if a person has a Chevrolet part that will fit a Corvette, naturally it gets listed as a Corvette part to attract the high bids.