Topic: 1966 Master Cylinder date code???

[Morsel]

I know there's a running thread about this, but wondering how I read the date code on this one. This is said to be an original 66 GT/ master cylinder and looking to purchase one for my car and want to know how to read this date or if this is a service part or something? I haven't seen this single digit "2", I've seen R2.

Thanks,

Jason

[J_Speegle]

The date in your picture is at the bottom where the cap lock engages with the main body

In your case it appears to read 154.

Using the Julian (you can find a chart for non-leap year date decoding in the Date Code article in the Library) it indicates that the 154th day was June 3rd if that was a non-leap year  If it was then the date would be June 4th

cane you check to see if the fitting openings have the seat or not. Guessing that they might not be there indicating the year that the master cylinder was made and in turn helping you determine if it would be correct for your car

[Morsel]

Well, if this is June 66, it's too late for my car since my car has a build date of February 10th. Also, since this is using the Julian system, how do we know what the year is when looking at master cylinders, is there another number I can see to tell. Obviously I'm in search of one and want to know at a glance if it would work for my car...

Anyway, here are more pictures of the item in question that the seller sent me, hope this answers your question about the inlet Jeff.

Thanks as always,

Jason

[evantugby]

Well, if this is June 66, it's too late for my car since my car has a build date of February 10th. Also, since this is using the Julian system, how do we know what the year is when looking at master cylinders, is there another number I can see to tell. Obviously I'm in search of one and want to know at a glance if it would work for my car...

Anyway, here are more pictures of the item in question that the seller sent me, hope this answers your question about the inlet Jeff.

Thanks as always,

Jason

This master cylinder looks just like the one I have with a "200" date code which equates to 19 July.  My kar was built Oct 23 1965 so the master cylinder you are thinking about buying might be from 1965.  The stamped number also is the same, except I have an "R5" at the end, which perhaps someone can shed a light on.

You can also see the ink mark of 1065.  Not to hijack your thread but since we're on the subject of master cylinders, hoping someone can confirm if master cylinder's were ink marked with a number on the bottomside.  What color would it have been?

[J_Speegle]

Well, if this is June 66, it's too late for my car since my car has a build date of February 10th. Also, since this is using the Julian system, how do we know what the year is when looking at master cylinders, is there another number I can see to tell. Obviously I'm in search of one and want to know at a glance if it would work for my car...

I think I posted in the other thread a picture of the attachment hole for the master cylinders that did not need the adapter. Yours looks like the earlier version that needed the adapter so that would suggest IMHO that the it was June 1964  and likely too early for your application for the date and because the need for the adapter

Later non-adapter master cylinder. Can you see the difference?

See the raised seat for the end of the brake line?

[Morsel]

I think I posted in the other thread a picture of the attachment hole for the master cylinders that did not need the adapter. Yours looks like the earlier version that needed the adapter so that would suggest IMHO that the it was June 1964  and likely too early for your application for the date and because the need for the adapter

Later non-adapter master cylinder. Can you see the difference?

See the raised seat for the end of the brake line?

Yes, this makes perfect sense and explains a lot. I also saw on the other thread that some actually had a different date code setup instead of the Julian, a 66 master cylinder with 4-6 that you posted... well at least I know what to look for now, helps out a lot...


Well let the search continue then:)

Thanks as always Jeff.

Jason