Master cylinder out of 6s1604

[Cjc6566]

Hey guys, I am no where near as versed as the experts and in the old forum I would just search this topic but in the new world post melt down I will put out to the group attached are pictures of the master cylinder I just pulled out of my car... is this original? And if so or not how do I tell ?  And finally to make this an efficient post is this worth rebuilding?

Thank you for the replies.

Cory C 6s1604

[Bob Gaines]

Hey guys, I am no where near as versed as the experts and in the old forum I would just search this topic but in the new world post melt down I will put out to the group attached are pictures of the master cylinder I just pulled out of my car... is this original? And if so or not how do I tell ?  And finally to make this an efficient post is this worth rebuilding?

Thank you for the replies.

Cory C 6s1604

That is original Bendix master cylinder. It has the Bendix trademark and the correct ID numbers. It is the early type that used a brass adaptor between the pipe thread in the master and the flare thread of the brake lines.

[98SVT - was 06GT]

The concours guys can tell you if the casting numbers are right for your car. There was a place that would bore them out and insert a stainless sleeve in case yours is pitted. The stainless bores (calipers, wheel cylinders, master cylinder) are great for cars that don't see a lot of use since the moisture in the system seems to seek the low spot and corrode causing leaks. Stainless lines are also good and you can spray them zinc color so they look stock.

[Bob Gaines]

The concours guys can tell you if the casting numbers are right for your car. There was a place that would bore them out and insert a stainless sleeve in case yours is pitted. The stainless bores (calipers, wheel cylinders, master cylinder) are great for cars that don't see a lot of use since the moisture in the system seems to seek the low spot and corrode causing leaks. Stainless lines are also good and you can spray them zinc color so they look stock.

The picture Master is a concours correct version if your 66 car used the adapter . The master evolved to not need the adapter in later 66 production.  Stainless lines will not make much of a difference compared to regular terne steel lines unless you are comparing 50 years done the road . Stainless because it is harder then stock lines has a tendency to leak because the flare will not slightly deform to conform to the mating surface when tightened like the original type terne steel. Forget painting to make more original .  Don't waste your time because you are trading one non original look for another. If you use conventional fluid you must change no more then every two or three years. Conventional eats paint when it leaks. If you use Dot 5 silicone the moisture will not build up in the lines like they do with conventional fluid .Many restorers use the silicone because it will not absorb water like the conventional because it will not eat paint and you can install it and forget it for a decade. It gives a slightly softer pedal when you are driving on the track so if you are doing that you have to decide. You will not notice any difference with a pleasure driven car.   

[J_Speegle]

Hey guys, I am no where near as versed as the experts and in the old forum I would just search this topic but in the new world post melt down I will put out to the group attached are pictures of the master cylinder I just pulled out of my car... is this original? And if so or not how do I tell ?  And finally to make this an efficient post is this worth rebuilding?

Cory can't tell from the picture. What is the date code on the bottom?  Its kind of in the shadows.

[Cjc6566]

Thanks for the quick replies- added one more picture with date code...  this new forum works great as far as adding attachments which was something I struggled with before..

Looks like I have a weekend project cleaning and rebuilding it-

Cheers

Cory C

[J_Speegle]

Cory - Looked through all my pictures and notes and have to offer that I can't find any thing supporting that this is the original one for your car. Nor  the correct style (with fittings) for a car in the 1600's.

Right now I've have examples of no-fitting disc brake master cylinders starting on San Jose built cars starting in the 6R127 range. Ford VIN since survey would include both disc brake Mustangs and Shelbys since there was no difference on the line between the two at San Jose in this detail.  Way, before your car was likely built. Believe 6S1203's is a no-fitting version also but that is just one of many I have records of.  Survey has produced a pretty hard line indicating the change over so the data appears to confirm that range but have started a survey on our site to get more data along with date codes from the master cylinders to back up matching car and unit.

Just thought I should share historical data and info to the discussion

[TLea]

Cory - Looked through all my pictures and notes and have to offer that I can't find any thing supporting that this is the original one for your car. Nor  the correct style (with fittings) for a car in the 1600's.

Right now I've have examples of no-fitting disc brake master cylinders starting on San Jose built cars starting in the 6R127 range.  Way, before your car was likely built. Believe 6S1203's is a no-fitting version also but that is just one of many I have records of.

Just thought I should share historical data and info to the discussion

+1. Seems very late for brass fitting style

[Bob Gaines]

Cory - Looked through all my pictures and notes and have to offer that I can't find any thing supporting that this is the original one for your car. Nor  the correct style (with fittings) for a car in the 1600's.

Right now I've have examples of no-fitting disc brake master cylinders starting on San Jose built cars starting in the 6R127 range.  Way, before your car was likely built. Believe 6S1203's is a no-fitting version also but that is just one of many I have records of.

Just thought I should share historical data and info to the discussion

I too am skeptical that a car with your VIN came with the adapter also. It would more likely be the evolved version that didn't need the adapter IMO. That is why I phrased my response ( if your 66 car used the adapter) to address only the originality aspect of the master itself and not whether it was original to your car or not.

[J_Speegle]

Just to be clear since my posting of 6R127 was likely confusing to some and some may have assumed it was a typo. So to be clear. Currently I am using, as we often do, Ford VINs to compare and organize findings since this is a Ford detail not a Shelby one. This allows me to include more data points (Mustangs built at San Jose in this example) which should make the findings more accurate and correct. Since they were built side by side, parts provided by the same vendors and installed by the same workers it's the best practice IMHO

So to be clear - currently the change over point I see indicated is around cars with Ford VINs starting with 127xxx. Since cars were not assembled/finished in sequential order the range is likely a few thousand one direction or another. Plus they (the workers supplying the bins or shelves) likely didn't wait until the bin was empty of all master cylinders before they refilled it.  So you might have had a few stragglers. If the bin held individual cylinders then there may have been no stragglers. 

Hope this helps explain better my earlier post - that I went back and added to.

[Cjc6566]

Thanks all- it won't change my weekend plans to clean and rebuild the master cylinder but it will be a new post under items wanted as I search for the correct replacement!  Feel free to PM me if you know a direction of a correct replacement.

Best Regards,

Cory

[Bob Gaines]

Thanks all- it won't change my weekend plans to clean and rebuild the master cylinder but it will be a new post under items wanted as I search for the correct replacement!  Feel free to PM me if you know a direction of a correct replacement.

Best Regards,

Cory

Cory, you will be glad to know that the later style without the need for a adapter is the easiest to find . If you find a core it will more likely be the later design then the earlier. They sell on ebay frequently.