[Jeff Hamlin]

Just like wheel cylinders these can be rebuilt.
Check local auto supply for overhaul kit.

If you're not comfortable doing it I'm sure you could find a local shop to handle it or...
http://www.whitepost.com/brake.html
They have been offering this service for years.

[60sstuff]

Originally Posted by Sloan66

Not to hi-jack the thread, but does anyone rebuilt the masters cylinders? I had to replace my original ( which was identical to 60sstuff) all the replacements are not even close, multiple line locations, bleeder on top, etc. The bore in mine is pitted, tried to hone it but still has small leak. Would love to put m original back on car if anyone has a source.

Rebuild kits are questionable and since mine needed sleeved I went with a known professional company that's been doing this type of service for years as mentioned above - White Post Restorations, Virginia (www.whitepost.com)
Not cheap, but your GTO is worth it!

[6t5gto]

This appears to be correct for 65 GTO at first glance, but I think its not original. Its in a car that has been in storage for 30 years and it has its original drivetrain and original paint. These are the #s on the bottom. The date is very hard to see. The car build date is 11c Baltimore. Does anyone see what the date is?

[6t5gto]

Side by side pics of mine and 60sstuff.

[dld]

looks after market .the EIS was a company that made brake parts. the car is not that original. head is wrong . we just went through that .

[6t5gto]

Yes. You are correct. I have 16 GTOs left and I mixed up the pics and paperwork with the dates.

[6t5gto]

The pic from the shop manual also looks different than the pic posted by 60sstuff. Is the shop manual picture different because its an illustration?

[RAII 4-speed]

here are 2 pictures from a 1965 shop manual...... I believe that the 1965 MC should look like these..............

[dld]

Originally Posted by 6t5gto

The pic from the shop manual also looks different than the pic posted by 60sstuff. Is the shop manual picture different because its an illustration?

If you notice the image in book shows the oil breather on the left bank. also the upper radiator hose is feeding the rad to the left side.

[RAII 4-speed]

Originally Posted by 6t5gto

This appears to be correct for 65 GTO at first glance, but I think its not original. Its in a car that has been in storage for 30 years and it has its original drivetrain and original paint. These are the #s on the bottom. The date is very hard to see. The car build date is 11c Baltimore. Does anyone see what the date is?

here one on e-bay ...... http://www.ebay.com/itm/EIS-RE40000-...-/171236035857

[6t5gto]

That is exactly the same one I posted that is in my 65. Even the brand name is the same.

[60sstuff]

Minor error in one of my above posts - the factory photo I used earlier as an example and (below) is actually from a Pontiac News Flash, Not the 66 shop manual.

It is a 66 model as noted above (LH oil fill breather cap, head bolt design) with PB being highlighted about the clearance of brake pipe to steering column shaft issues.

I used a mirror to look under my master cylinder and can not make out any clear information. This MC was rebuilt/sleeved by White Post and came back after being blasted and painted. I am third owner of this 66 so I can not vouch for it still being the exact assembly line unit.

[RAII 4-speed]

update ........
My original unrestored non power MC is casting number 5484293 with a julian date of 133 3 I assume that date is the 133 day of 1963 and it is original to my 1965 GTO built 12A (first week of December 1964). below is a picture of my MC on my car as well as another MC that I own with the same casting number and a date of 197 3 also a possible 1965 application.
6T5GTO that started this thread might possibly have the correct MC for a 1965 power brake. the one posted on the left in the first posting of this thread is casting number 5484343 with a date of 307 3. (307 day of 1963) Yes that could be used for a 1965 application. If anyone has a master parts catalog and can look up that casting number it will show the proper application as there seems to be no one with an original unrestored power brake car.
I hope this helps

THIS IS MY UNRESTORED NON POWER MC AS DISCUSSED ABOVE......



THIS IS THE EXTRA NON POWER MC THAT I HAVE ...

[6t5gto]

This is another power mc with the same part # as the 1st one I listed, but looks like a date of 66th day of 1961

[dld]

But as we have seen before. the casting # may have several part numbers after machining for end use.

[John V.]

My NON-PB late Nov. '63 built '64 GTO has a 5464293 casting, Julian date code of 268 and a 3 after the date tag. Pretty sure it has never been disturbed since the car was built, still on the firewall now.

I'm not certain that the 3 indicates the year but since it would "work" for mine, can't say for sure.

Since that no. appears to have been stamped, it may indicate an application or some other bit of info, not necessarily the year of casting.

The MPC does you no good.

Pontiac did not service the bare body casting.

The p/n in the MPC is for the m/c ASSEMBLY, so carries a specific assembly p/n.

The body casting p/ns are not in the MPC.

RAII, I don't know what to make of that spare 5464293 of yours. The markings are almost TOO distinct. Mine appears more like your original and in particular, the boss on the bottom of your spare seems overly deep, hard to imagine that my original or yours started that distinct and wore down.

I also agree that multiple applications can be machined from a particular casting body, especially if the casting has multiple bosses (top, bottom, sides, front) to accommodate various line connections.

Looks to me that the factory ONLY machined the specific bosses for a given application, even when additional bosses were part of the casting.

Question I have is whether they used the casting seen in the News Flash pic, lacking the top boss, in '64 and/or '65. Maybe that is a new for '66 m/c casting, not used prior? Since it lacks the top boss, it surely is not the 5464343 casting.

6t5gto, casting p/n 5464343 seems to be a possibility when machined for the right side bleeder and the left side outlet pipe with no other bosses drilled.

But I sure don't know for sure if that casting was used in '64 and/or '65.

[RAII 4-speed]

Originally Posted by John V.

My NON-PB late Nov. '63 built '64 GTO has a 5464293 casting, Julian date code of 268 and a 3 after the date tag. Pretty sure it has never been disturbed since the car was built, still on the firewall now.

I'm not certain that the 3 indicates the year but since it would "work" for mine, can't say for sure.
ACTUALLY MY ORIGINAL WOULD HAVE BEEN 3 MONTHS INTO THE 1964 YEAR IF WE USE THE 3 AS THE REFERENCE YEAR, THUS MAKING MINE AWAITING INSTALL FOR 9 MONTHS, SEEMS UNLIKELY. SO I AGREE THAT THE 3 IS POSSIBLY NOT FOR THE YEAR.

Since that no. appears to have been stamped, it may indicate an application or some other bit of info, not necessarily the year of casting.
AGREE.

The MPC does you no good.

Pontiac did not service the bare body casting.

The p/n in the MPC is for the m/c ASSEMBLY, so carries a specific assembly p/n.

The body casting p/ns are not in the MPC.
I NOW UNDERSTAND.

RAII, I don't know what to make of that spare 5464293 of yours. The markings are almost TOO distinct. Mine appears more like your original and in particular, the boss on the bottom of your spare seems overly deep, hard to imagine that my original or yours started that distinct and wore down.
MY ORIGINAL IS IN AN INCREDIBLE UNRESTORED CAR AND YOU ARE RIGHT THAT MY SPARE IS VERY PRONOUNCED. I DON'T THINK OURS WORE DOWN, I THINK IT HAS TO DO WITH THE WAY IT WAS CAST OR THE WEAR IN THE CAST.

I also agree that multiple applications can be machined from a particular casting body, especially if the casting has multiple bosses (top, bottom, sides, front) to accommodate various line connections.
I THINK THAT IS ONLY ON AFTERMARKET MASTER CYLINDERS ALL ORIGINALS THAT I HAVE SEEN DO NOT HAVE ALL THE BOSSES/KNUCKLES.
IT WOULD BE INTERESTING TO SEE A DELCO LOGO WITH A CASTING NUMBER ON A MC THAT HAS ALL THE BOSSES/KNUCKLES.

Looks to me that the factory ONLY machined the specific bosses for a given application, even when additional bosses were part of the casting.

Question I have is whether they used the casting seen in the News Flash pic, lacking the top boss, in '64 and/or '65. Maybe that is a new for '66 m/c casting, not used prior? Since it lacks the top boss, it surely is not the 5464343 casting.
TRUE... AGAIN I WOULD LIKE TO SEE AN ORIGINAL 1966 WITH THE BOSSES AND DELCO CASTINGS.

6t5gto, casting p/n 5464343 seems to be a possibility when machined for the right side bleeder and the left side outlet pipe with no other bosses drilled.


But I sure don't know for sure if that casting was used in '64 and/or '65.

DOES ANYONE HAVE AN ORIGINAL 1966 THAT THEY CAN TAKE PICTURES OF SHOWING ALL SIDES AND CASTINGS?

[John V.]

RAII, if you want to see a '66, your best bet is to start a new thread in the '66-'67 forum.

[RAII 4-speed]

Originally Posted by John V.

RAII, if you want to see a '66, your best bet is to start a new thread in the '66-'67 forum.

Yes ... Thank you