65-66 non-power brake master cylinder; repro vs. original

[Gary B.]

Can anyone tell me if the current repro non-power brake master cylinder for '65-'66 is detectably different from original or NOS examples?

Thanks,

Gary

[Wayne M.]

Re: 65-66 non-power brake master cylinder; repro vs. original

Can anyone tell me if the current repro non-power brake master cylinder for '65-'66 is detectably different from original or NOS examples? Gary

Gary -- can't answer your question, but as I see it's been 7 hours and no one else has responded, can I put a related question to you ?

I have two '65's. To my chagrin, I discovered about 10 years ago, when reading my '65 TIM&JG that one of my two was not factory correct (see attached thumbnail, taken with mirror, then flipped digitally so the cast number 618967 reads correctly).

Other car has the casting # 2225032 in same location, and is correct per TIM&JG.

My question: is the 618967 an early service unit (prior to 1980 when I bought the car) ? I haven't compared both side by side, but they appear identical otherwise.

[William C.]

Re: 65-66 non-power brake master cylinder; repro vs. original

I believe the originals have a casting date on the bottom of the casting should a judge decide to use a mirror in that area.

[Gary B.]

Aftermarket/Generic vs. repro vs. NOS vs. original

Wayne,

It turns out I must have 3 master cylinders; one almost certainly an aftermarket or generic (on the car) that does not have the correct casting number on the bottom; one repro (that I temporarily can't locate in my badly organized inventory) that from memory has the correct casting number on the bottom; and one NOS that I know has the correct casting number on the bottom and what looks like "R6", which may or may not be a date code.

Gary

[Gary B.]

Date code?

Wayne,

The other embossed info on my NOS cylinder looks like a "145" that appears on the underside where one of the bails (sp?) sits. Maybe this means the 145th day of the year?

Gary

[Rob M.]

Re: 65-66 non-power brake master cylinder; repro vs. original

HI Gary,

I replaced the MC on my '66 with a reproduction a couple of years ago. I don't remember the reproduction MC having the Julian date on it. It did have the correct casting number however and did pass judging. The MC that I took off the car and have kept does have a Julian date on it (I don't remember the number off the top of my head). Hope this helps.

Rob

[Gary B.]

Julian date

Rob,

So the 145 under the bail on my NOS example is the 145th day of some year?

Gary

[Wayne M.]

Re: Julian date

Rob,

So the 145 under the bail on my NOS example is the 145th day of some year?

Gary

I would say so. Here's some further info from my two.

The Julian dates are on the outboard bail indent; on the one I show in the pic above (with the non-approved cast #) has '183'. The date on my other is '050'. IMO, that symbol is a 'flying' "P" superimposed over a second character. Perhaps it is a Bendix trademark. I know there has been RESTORER articles on this stuff. but can't locate. The "R" and a single digit that follows is probably the mold #.

The '65-8 P&A30 Gr 4.650 shows the '65-6 master cyl as GM # 3866446, with descriptive (Bendix 618690...).

[Rob M.]

Re: 65-66 non-power brake master cylinder; repro vs. original

Gary,

I can't promise that to be the case, however that is what I learned from other members when I was researching master cylinders a couple of years ago. Someone with more expertise might verify for us. What I do know is that the MC that came off the car (and I have no reason to believe it wasn't original) had 3 stampings on it - the casting number, a letter/number combo (like R6 or R5) and what I believe is a julian date. I think the julian date on mine was in the high 200's. I don't have access to it right now, so I can't be certain.

I would be happy to email you a picture of mine when I get home from our holiday vacation. Let me know.

Rob

[Gary B.]

65-66 non-power brake master cylinder

Rob,

I don't think a photo is needed, but thanks for the offer. My NOS example sounds like it will work perfectly for me based on the 145 julian date for my July car.

Thanks,

Gary

[Bob J.]

Re: Julian date

The "R" and a single digit that follows is probably the mold #.

If the "D" on later master cylinders is the Danville.IL. foundry does anybody know which foundry the "R" represents? Bob

[Gary B.]

D for Danville; R for ???

Bob,

I couldn't find anything in the archives on the R letter.

Gary

[Peter J.]

Re: 65-66 non-power brake master cylinder; repro vs. original

Gary,
I have a 149 for a late june car, so I think you are right 145 should work for a july build car.