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I should probably clarify: My current master cylinder leaks and i want upgrade to front discs soon. Now my question: Can i use this master cylinder with my drums until i swap over to discs in a few months? I don't plan to keep it with drums. I know that doesn't make sense.
But i think i will just buy a cheap 4 wheel drum cylinder for 30$ as a temporary solution until i convert to discs.
You can buy a 67 drum/drum master at O'reillys for very little. Use it till you are ready to convert. Throw the drum/drum master in the junk, put on a front disc/rear drum master--If manual brakes- The MC 36440 will work great.
If you buy a 36440 now with drum/drum, you will need to put in a 10# residual for the front drums.
 

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The 67 does NOT use a "proportioning valve" period. That round valve found at the rear on 67 and at the distribution block on 68 up is a 3 PSI residual valve. It was bench tested as well being this became a contested fact with a few because many gave it the label proportioning valve. I'm not confused about function or form. I was speaking from the 67-70 vehicles view point.
Being the master he posted is a dual-bowl unit, which I know many with 65-6 cars changed for safety reasons.
 

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My dad told me many years ago--
You can lead a horse to water, but you can't make him drink.
 

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The drum/drum cars didn't use a use a proportioning valve. Every disc/ drum car from 65-69 used an inline proportioning valve, until it was incorporated into the combo valve in 70.
The shop manual calls it a proportioning valve, and a brake pressure control valve. It's function is to proportion brake pressure.
 

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The drum/drum cars didn't use a use a proportioning valve. Every disc/ drum car from 65-69 used an inline proportioning valve, until it was incorporated into the combo valve in 70.
The shop manual calls it a proportioning valve, and a brake pressure control valve. It's function is to proportion brake pressure.
The same "residual valve" was used 67-70. They were relocated in 69 from the rear of the car at the junction for the line/rubber junction. The service manual does NOT call them a proportioning valve until 69. It's incorporated into the block assembly starting in 1969.
When you apply pressure it does NOT alter the pressure in. It does hold pressure post. That makes it a residual valve.
Not opinion, fact. I do not mean to be offensive, but this was debated until it was bench tested.
Dan at Chock is a great guy. We've done business and I recommend him highly. I am just stating the fact of function of the valve that is inline for the rear brakes. He's correct about the metering valve in the master cylinder as well on dual systems.
 

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You can ignore bench testing and Ford engineering information as well. It has nothing to do with brake balance. Period.
Sorry, but C7OZ-2B091-B was supplied to Ford by Wagner as a "brake pressure control valve," just as C5ZZ-
2B091-B was supplied to Ford by Kelsey-Hayes (#74155) as a brake pressure reducing valve for 65/66 cars.
We refer to such devices as brake proportioning valves in our common automotive lingo. Such valves can be
plumbed anywhere in line to the rear brakes and consequently some '67 proportioning valves can be found
all the way back by the rear axle. In contrast, a residual check valve is only found at the master cylinder port
or immediately after the outlet port, because if the residual valve is plumbed farther back, its effectiveness
in operation is reduced the farther rearward it is in the brake circuit.

ex-Global West GM
1991-1995


773593
773602
773603
 

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On page 2-9 of the 67 manual, it's called a proportioning valve. It doesn't need another RPV, it's already got one in the M/C.
The guy that supplies the rebuild kits to all the retailers, calls it a proportioning valve.
 

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On page 2-9 of the 67 manual, it's called a proportioning valve. It doesn't need another RPV, it's already got one in the M/C.
The guy that supplies the rebuild kits to all the retailers, calls it a proportioning valve.
We can call it a proportioning valve all day long. It doesn't function as one. It doesn't control brake bias.
The disc brake master only has the valve for the disc/front brakes, as Choco even agrees. The Drum/Drum does have the residual valve front and rear. There are no valves for the rear in a Disc/drum vehicle except in-line residual valve at the rear of the vehicle.(67)
I have rebuilt several 67 disc brake masters and residual valves over the last 40 years. ( Cougars and Mustangs, Thunderbird) You'll note this when you pull the brass flair out of the master during a complete rebuild. ( Not the hone and replace the piston kit)
The 65-66 Mustang in it's stock form is single master. It's a completely different animal.
 

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You sir, do not know what you're talking about.
Just because you believe something to be true does not make it true.

ex-Global West GM
1991-1995

773624
 
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This little do-dad, that you'll find at the rear of a '67 and adjacent to the distribution block on a '68-69 is a brake PROPORTIONING VALVE. It reduces the pressure to the rear brakes to prevent them from prematurely locking up causing a loss of control.
773625
 

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Got to be somewhat understanding. I get labels mixed up, get confused, think, discern, confused as well. WE all do that. So to mislabel is common human thing.
All is well.

Dag gone--I get so confused at times I can't find my ass with both hands!
 

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This little do-dad, that you'll find at the rear of a '67 and adjacent to the distribution block on a '68-69 is a brake PROPORTIONING VALVE. It reduces the pressure to the rear brakes to prevent them from prematurely locking up causing a loss of control.
View attachment 773625
This little do-dad, that you'll find at the rear of a '67 and adjacent to the distribution block on a '68-69 is a brake PROPORTIONING VALVE. It reduces the pressure to the rear brakes to prevent them from prematurely locking up causing a loss of control.
View attachment 773625
Once again, you've never bench tested the valve. This SAME valve is used in 1967 as well. IT DOES NOT LIMIT PRESSURE. IT WAS BENCH TESTED TO PROVE THIS. IT HOLDS PRESSURE TO THE REAR SHOES.
You can make up, claim, read from a catalog. Now I'm done. Talk about hard-headed and passing along misinformation.
 

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Page 2-13 of the 67 shop manual, Fords description of the function of the P/V. This is Fords understanding of its function.
But, I'm gunna guess that your testing will prove FORD wrong.
773702


And I'm out.
 

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Page 2-13 of the 67 shop manual, Fords description of the function of the P/V. This is Fords understanding of its function.
But, I'm gunna guess that your testing will prove FORD wrong.
View attachment 773702

And I'm out.
[/QUOTE
I have all the service manuals through 67. I'm not some shade tree hack.
The master cylinder pressure is the same at the master and post the residual valve.
That means it doesn't regulate any pressure going in or through. It does maintain pressure post the valve with NO pressure being applied to the pedal.
If it functioned as above I would agree. The 67 and later 68 systems are different. I would assume the block DOES actually function as a proportioning valve in the late 68-70 vehicles.
I am not against exchanging ideas.
My explanation of function for 67 isn't theory, it was tested with actual pressure gauges.
Hostility and insinuating one lacks intellect will get you bit quickly.
 
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