Guys, in my project, an early 67 c code convertible, i am switching from factory drum/drum to power disc/drum. My pedal and booster are factory pieces (albeit the pedal is a 68 factory disc version). I am using the Granada set-up in the front because I already owned it from another 67 project. I will eventually go the original Kelsey-Hayes type, but for the moment, it is the brand new Granada kit.

My question is this--can I safely and legitimately plumb the factory 67 external proportioning valve into the original distribution block?
Sure. The only drawback is an extra hole in the distribution block that must be plugged.

I know that the early 67 disc cars had this external valve located on the rear axle housing.
Not exactly, it was actually mounted on the floor of the car, a couple inches from the rear brake hose bracket.

I assume that these cars had the standard distribution block installed at the MC like the drum cars.
The disc brake distribution block was mounted on the fender apron, below the LH hood hinge, and it was physically different.

I envision plumbing it in a form that tracks the 68 version, which used the external valve plumbed to the block. However, it is clear that the 68 block is engineered differently from the standard drum/drum block.
The 68-69 distribution block was entirely different from the 67, and included provision for redirecting brake fluid.

EDIT: I just realized for the first time that the axle mount is inline on this setup and there is no place to plumb the external valve on the block.
There never was. It was simply spliced in-line in the steel line going to the rear brakes.

I guess that you could fabricate a way to mount it at the block area but it would have to be inline on the rear line.
Exactly. It just hung there near the block. Ford did it that way after 2/1/67.

I guess the safer and easier route is to get the 68 factory prop valve and do a direct bolt in using the 68 front lines?
All 67-69 disc brake Mustangs used the same proportioning valve. To use the 68 lines, you'll need the unique 68-69 distribution block.

I have searched for an answer on this, but not finding much. I know that I could go with the less expensive adjustable valve, but i don't want to custom fabricate on brakes any more than absolutely necessary. And it seems like my idea could be reasonable solution using the 68 factory disc hard lines--looks like it would be a plug and play, if the fittings are the same size, at least.
To use the 68-69 distribution block, you'd need to find and buy one, hoping it would be in good condition, or rebuild it. Definitely not plug and play. Or you could simply buy a new 67-69 proportioning valve and install that.

The adjustables start at about $35, while the OEM repro runs $70.

 

As David pointed out, it's just an inline valve. It doesn't have to have anything to do with the distribution block. In '68/'69 they simply attached it in the same general area, as the block, but still is completely separate. So you can add it up front, in the rear or under the car, no difference. I might suggest the best way to is buy an adjustable proportioning valve so you can adjust bias as you desire.

 

Thanks Pete and David. I guess that I outsmarted myself on this one. I picked up the front 68 disc lines thinking that I would buy the repo 68 prop valve from NPD and that it would all just fit without having to customize. It sounds like I over Frankenstein-ed my set up unintentionally. Sounds like I need to go back with the 67 front lines (different size fittings I am guessing?) and install the factory style inline valve (or aftermarket adjustable version) in the rear brake line between the distribution block and the rear brakes?

 

What i think you want to do is what I did with my May 10th late built 67 GT.
You wanna set it up like the '68 style where prop valve is mounted up front but for a '67.
If you do the research like I did, NPD sells 3 diff brake line kits just for '67. They call it "early style", "late style" then "VERY late style". The very late style will give you all the proper lines. It's what I did. See my pic.
https://www.npdlink.com/store/products/mustang_brake_line_set_front_disc_carbon-103999-2794.html

 

The 1968/1969 block had 7 ports vs 5 on the 1967. The two additional ports allow the PV to be mounted to the block. Hydraulically the PV is inline between the MC and the rear wheel cylinders on both 67 and 68/69 - the later block/bracket just allowed Ford a convenient way of mounting the PV near the block where it was easier to service.

1967 disc brake distribution block (note that the PV is mounted at the rear of the car but inline with the port that goes to the rear brakes - lower left in pic):

1968/1969 disc brake distribution block:

Paul

 

Quite interesting. My factory PB front disc 1967 PV looks exactly like the 1968/69 setup. Gonna have to look at my car's build date.


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