Topic: "Early" 1967 Brake Proportioning Valve?

[CT428CJ]

This is one of the -B valves.

[RoyceP]

Yep, same kit I bought. I remembered only one line but maybe there were two needed. In any case it fit and worked fine. Obviously not concours correct!

This is one of the -B valves.

[jwc66k]

Yep, same kit I bought. I remembered only one line but maybe there were two needed. In any case it fit and worked fine. Obviously not concours correct!

This is a prime example of the perils of NOS parts. You get what Ford service used to keep a customer's car running, not always what the factory originally used. Remember, Ford was not building concourse grade cars.
Years back, a 67 "A" code Fastback I was helping a friend to restore, had his power brake booster rebuilt. On the shelf in back of the order desk were a couple of the correct cylinder style proportioning valves (for reference, Ford engineering part number C7OA-2B91-C, service part number C7OZ-2B091-B).
You might give them a call:
Power Brake Exchange
260 Phelan Ave
San Jose, Ca, 95112
408 292-1305
Jim

[196667Bob]

Although my '67 does not have disc brakes, I found this thread intriguing, and decided to do a little digging on my own. Like Jeff, I started with my 1967 only, Parts and Accessories Catalog (dated January 1967). Like Jeff, I saw that the valve had the Part Number of C7OZ-2B091-B. This raised a "red flag" to me, as no other application is shown with a C7OZ-2B091-A Part Number. This would then imply that a C7OZ-2B091-A must have preceded the "-B". My next "stop" was the 1967 Chassis Assembly Manual to see what it shows. That proved a waste of time ; I don't know about the rest of you, but mine is of such a poor quality that one can't read numbers, and some appear to be missing completely. It does appear to show the cylindrical valve, but the arrow going to it (which would go to the Engineering Number), goes to open space. The sheet is undated, with no "Revision Date(s) shown, so it may be the original "first" design ?

I then went to the 1960-68 MPC. I started with the Illustrations Section, which was more revealing than the Assembly Manual had been. I have attached copies of two page from the Illustrations Section; first is the page for 1967 Mustang Brake System, and second is for 1967 Fairlane and Falcon Brake System. Remember that the Fairlane and Mustang are both noted in the 1967 Only MPC as using Part Number.C7OZ-2B091-B.  Note that the last Revision (at least through April of 1968) to the Mustang page (page 25) is August of 1967. Yet, the last Revision to the Fairlane-Falcon page is October 1967. While the Mustang page shows only the cylindrical valve, the Fairlane-Falcon page (page 24) shows the cylindrical valve and the "Alternate" "Block-type" valve. Possibly page 25 should have been Revised in October also ?

Now, on to the 1960-68 Text Section. Here is where there is at least a little light shed on this matter. In the text section, the Part Number for the Valve is =once again shown as 
C7OZ-2B091-B (page 25, dated August 1967) ; however, there is a "Ø" symbol noted next to it. Checking the "General information Section of the Text, gives the following description ; "Ø Indicates changes and additions such as change in model application, dimension, etc.". This is a pretty good indication that another part (possibly C7OZ-2B091-A) preceded the "-B" ?

On to the OSI Catalogs. Sure enough, in the July 1967 OSI, it shows that the C7OZ-2B091-A is "NR" (not replaced). It is shown as NR as opposed to "r/b" (Replaced By) since the C7OZ-2B091-B is not a "direct" replacement.

One more "check" I decided to make ; check my May 1967 Ford List Price Book. Interesting here is that Part Number C7OZ-2B091-A is listed (for $46.05) but the "-B" is not yet listed. Unfortunately, that is the latest Price Book I have.

One final look was at the 1965-72 MPC. In the Text Section, the applications are still shown for Fairlanes, Falcons and Mustangs, but now the year applications are shown as "67/69". In the Illustrations Section, it appears that they just used the same ones as in the 1960-68 MPC, with the 1967/68 Mustang one showing the cylindrical valve back by the rear end. However, on the Illustration for the 1969/70 Mustang, it shows the cylindrical valve at the front, on the rear inner fender apron, hooked into the Brake Pressure Differential Valve.

One thing to remember ; all of the above is based on Service Parts, not Factory instaslled parts. While early issues of Service Parts may be the same, such is not guaranteed. As for time difference, my guess would be that when Ford decided to make the change from "-A" to "-B", their intent would have been at the Plants, to use up the "-A's" that they had, before moving to the "-B's". Thus, the Plants' changes could be at different times from when the Service Parts were available.

There you go ; the results of my "digging". Confusion supplied at no extra cost.

Bob

[Bob Gaines]

Although my '67 does not have disc brakes, I found this thread intriguing, and decided to do a little digging on my own. Like Jeff, I started with my 1967 only, Parts and Accessories Catalog (dated January 1967). Like Jeff, I saw that the valve had the Part Number of C7OZ-2B091-B. This raised a "red flag" to me, as no other application is shown with a C7OZ-2B091-A Part Number. This would then imply that a C7OZ-2B091-A must have preceded the "-B". My next "stop" was the 1967 Chassis Assembly Manual to see what it shows. That proved a waste of time ; I don't know about the rest of you, but mine is of such a poor quality that one can't read numbers, and some appear to be missing completely. It does appear to show the cylindrical valve, but the arrow going to it (which would go to the Engineering Number), goes to open space. The sheet is undated, with no "Revision Date(s) shown, so it may be the original "first" design ?

I then went to the 1960-68 MPC. I started with the Illustrations Section, which was more revealing than the Assembly Manual had been. I have attached copies of two page from the Illustrations Section; first is the page for 1967 Mustang Brake System, and second is for 1967 Fairlane and Falcon Brake System. Remember that the Fairlane and Mustang are both noted in the 1967 Only MPC as using Part Number.C7OZ-2B091-B.  Note that the last Revision (at least through April of 1968) to the Mustang page (page 25) is August of 1967. Yet, the last Revision to the Fairlane-Falcon page is October 1967. While the Mustang page shows only the cylindrical valve, the Fairlane-Falcon page (page 24) shows the cylindrical valve and the "Alternate" "Block-type" valve. Possibly page 25 should have been Revised in October also ?

Now, on to the 1960-68 Text Section. Here is where there is at least a little light shed on this matter. In the text section, the Part Number for the Valve is =once again shown as 
C7OZ-2B091-B (page 25, dated August 1967) ; however, there is a "Ø" symbol noted next to it. Checking the "General information Section of the Text, gives the following description ; "Ø Indicates changes and additions such as change in model application, dimension, etc.". This is a pretty good indication that another part (possibly C7OZ-2B091-A) preceded the "-B" ?

On to the OSI Catalogs. Sure enough, in the July 1967 OSI, it shows that the C7OZ-2B091-A is "NR" (not replaced). It is shown as NR as opposed to "r/b" (Replaced By) since the C7OZ-2B091-B is not a "direct" replacement.

One more "check" I decided to make ; check my May 1967 Ford List Price Book. Interesting here is that Part Number C7OZ-2B091-A is listed (for $46.95) but the "-B" is not yet listed. Unfortunately, that is the latest Price Book I have.

One final look was at the 1965-72 MPC. In the Text Section, the applications are still shown for Fairlanes, Falcons and Mustangs, but now the year applications are shown as "67/69". In the Illustrations Section, it appears that they just used the same ones as in the 1960-68 MPC, with the 1967/68 Mustang one showing the cylindrical valve back by the rear end. However, on the Illustration for the 1969/70 Mustang, it shows the cylindrical valve at the front, on the rear inner fender apron, hooked into the Brake Pressure Differential Valve.

One thing to remember ; all of the above is based on Service Parts, not Factory instaslled parts. While early issues of Service Parts may be the same, such is not guaranteed. As for time difference, my guess would be that when Ford decided to make the change from "-A" to "-B", their intent would have been at the Plants, to use up the "-A's" that they had, before moving to the "-B's". Thus, the Plants' changes could be at different times from when the Service Parts were available.

There you go ; the results of my "digging". Confusion supplied at no extra cost.

Bob

FYI the cylinder on the 69/70 is the brake proportioning valve although similar in appearance to the 67/68 one it has a C9 engineering number stamped on it. It is plumbed next to the distribution block.  I believe what we are calling a proportiong valve is the same as Brake Pressure Differential Valve.

[jwc66k]

I saw that the valve had the Part Number of C7OZ-2B091-B. This raised a "red flag" to me, as no other application is shown with a C7OZ-2B091-A Part Number. This would then imply that a C7OZ-2B091-A must have preceded the "-B".

Bob,
The Ford part numbering system changed dash numbers, in this case the -A and the -B you referenced, when a design change was made OR when a different supplier made the identical part. Without the backup documentation, you would need sample parts.

My next "stop" was the 1967 Chassis Assembly Manual to see what it shows. That proved a waste of time; I don't know about the rest of you, but mine is of such a poor quality that one can't read numbers, and some appear to be missing completely.

Don't blame the messenger. Osborn Reproductions did the best the could with what Ford provided.
All the Mustang Chassis Assembly Manuals did not include the full Ford assembly line part number in all applications, and the drawings were sloppy as well. The lack of a full part number had to have been a decision by Ford purchasing and the assembly line people. They most likely used a printout, computers in industry were just coming into being.
Jim

[196667Bob]

See what I meant about confusion ? What we commonly call the "Proportioning Valve" is designated by Ford as "Front Disc Brake Pressure Control Valve" and what we commonly call the "Distribution Block" is designated by Ford as the "Brake Pressure Differential Valve".

As far as the "C9", I'll be the first to say that I don't know much about 1969 details. I was just passing on what is shown in the 1965-72 MPC. Obviously they either made a mistake noting the 69 as the same part number, or by 1975, the C9 was "NR" and replaced by the C7.

Bob

[krelboyne]

C7 and C9 brake proportioning valves appear identical.

[1967 eight barrel]

Those are not original to any 67. The residual valve should be under the floor at the rear of the vehicle. It simply holds 2LB of fluid pressure. We had this discussion elsewhere and It was tested to do exactly as I stated. The distribution block on a '67 vehicle also does NOT  function as a proportioning valve. It is a safety valve that slides to whichever side loses pressure as to keep fluid in the system. A shuttle valve would be more accurate.  That was an over the counter replacement for the original residual value. The valves were moved to the LH apron next to the master starting in 1968.
                                                                                         -Keith

[jwc66k]

The valves were moved to the LH apron next to the master starting in 1968.

I believe the valve was a running change in the April-May time period of 1967, at least in San Jose. I assisted a friend restore a May 67 Fastback about 10-12 years ago and that was what we found.
Jim

[67gta289]

+1 not a hard stop change over at the end of the model year.

[Bob Gaines]

I respectfully disagree that the 68 style of routing the proportioning valve was used at any time in 67 production. I have seen a number of other late production June builds that were as typical mounted in back which is the basis for my opinion. I think it is more likely that if a 68 style was found on a late 67 that it was because a PO had replaced it . Different distribution block,different brake lines , different brake warning switch and corresponding wiring harness plug are some other issues that would also need to be addressed besides the forward  placement of proportioning valve if a change was made in late production. I think this substantial change took place job 1 for the 68 production year until substantial evidence suggests otherwise.                                                     

[jwc66k]

Bob,
Look up NPD stock number 2265-25, which is listed for "67 - Very late, disc, w/front mounted proportioning valve -39.95". Also avaiable in stainless. They convinced me.
Jim 

[67gta289]

Using NPD as the sole source for something like this is somewhat risky.  I'll go back and look through my photos (a fraction of what Jeff has though) to see if there is any additional evidence one way or the other.

[RoyceP]

We had a discussion about this exact subject on the Cougar website recently. No one had seen any evidence of a '67 with the '68 style proportioning valve set up. Even the Master Parts catalog has zero evidence of anything being different in the late '67 model year. If anything had changed on the line it would normally be shown with an implementation date in the MPC.

I think someone at NPD is imagining something that didn't happen.

I respectfully disagree that the 68 style of routing the proportioning valve was used at any time in 67 production. I have seen a number of other late production June builds that were as typical mounted in back which is the basis for my opinion. I think it is more likely that if a 68 style was found on a late 67 that it was because a PO had replaced it . Different distribution block,different brake lines , different brake warning switch and corresponding wiring harness plug are some other issues that would also need to be addressed besides the forward  placement of proportioning valve if a change was made in late production. I think this substantial change took place job 1 for the 68 production year until substantial evidence suggests otherwise.