Correct master cyl for J50 brakes ?

[Ron Hambrecht]

I am trying to get my hands on a correct master cylinder for my 67 with J50 power brakes. I am looking at one that the owner insists is for manual disc brakes, but has the same part # (5455509). Is this possible ? The judging guide has 5455509 listed as the correct master for J50 power brakes, but apparently there is another power brake option (J56 or J58) ?

Can anybody educate me on the correct master cyl. for J50 power brakes ?

[Michael H.]

Re: Correct master cyl for J50 brakes ?

Ron,

There's been quite a bit of discussion on this subject lately on this board. It's probably a bit confusing but the story is, the #5455509 is the correct master cyl for all installations, both standard AND J50 power brakes, but not J56 HEAVY DUTY brakes. They are the same part number and are identical in every way.

The only application that requires different master cyl would be for cars equipped with the rare J56 heavy duty brake option.

Michael

[Ron Hambrecht]

Re: Correct master cyl for J50 brakes ?

Thanks Mike, that clears it up. Surprisingly this runs contrary to the info Hans provided in The Restorer, where he states that all power brake applications used 5480346, and ONLY manual brakes used 5455509. But no mention was made of the Heavy Duty Brake application.

[Michael H.]

Re: Correct master cyl for J50 brakes ?

I believe the confusion all started because the application list states "All, except J56" which includes power brakes. So, the assumption is/was, anything with power brakes requires a different part number master cyl.

I'll try to dig out and post the page from an old printing of the parts book so everyone can see the exact listing/description. It probably is a little confusing.

[Michael H.]

Scan of 67 Parts Book

This is the listing in a 1969 printing of the parts book for the 67 master cylinder. Note that it states 67 (exc. H.D. J56 Brakes), which means all other 67's use this unit, including those with power brakes. Also note that it all gets even more confusing when you look at the application for 68 and 69.

[Michael H.]

Scan of 67 Parts Book

Totally different part number for all 67's WITH J56 heavy duty brakes.

[Ron Hambrecht]

Re: Scan of 67 Parts Book

Thanks again Mike. I know this was confusing for many people.

[Joe L.]

Re: Correct master cyl for J50 brakes ?

Ron-----

As Michael has described, the 1" cylinder casting #5455509 was used for standard and J-50 power brakes for 1967. The '346' 1-1/8" cylinder was used for J-56 only.

What generates most of the confusion in this regard is the fact that this usage was unique to 1967. Although exactly the same master cylinders were used for 1968-76, the applications changed. For 1968-76, the 5455509 was used ONLY for standard brakes. Also, for 68-76, the '346' was used for BOTH J-50 and J-56 PB applications. Some folks think that the 68-76 applications also applied to 1967. 1967 was NOT totally the same, though. The difference relates to 1967 with J-50 only, though.

[Ron Hambrecht]

Re: Correct master cyl for J50 brakes ?

Joe/Mike:

Is it true that the #5509's for 1967 usage had no date codes on them ? I was told that this was the case only on the 67 #5509's

[Michael H.]

John Hinckley Would Know........

...if the 67 master cyl was the only one that wasn't dated. I'm not sure but I've heard that this the case. In fact, I think that same question was asked here not long ago and I believe it was John that answered it.

[John H.]

Re: John Hinckley Would Know........

Some 509's were dated (tiny julian stamp on the front outlet spotface), and some weren't; I've seen a photo somewhere of a dated one, but have never seen one personally. Every one I've ever had was not dated.

[Dick W.]

Re: John Hinckley Would Know........

Date code usage was sporadic on the 68-72's also

[Patrick H.]

Re: John Hinckley Would Know........

Try and tell that to the judges who take off the point for no date.

PH

[Brian M.]

Re: John Hinckley Would Know........

How about a date after the car build date? Remember the date is not judged.

[Harmon C.]

Re: John Hinckley Would Know........

Patrick

I have allways found a date after cleaning the spotface of rust on any I have owned. The numbers are small and some may be rusted to a point you can't read the numbers.At one time we only looked for the date on Bowtie judging but if the manual says date I think no date is a deduction.

Lyle