Topic: "Early" 1967 Brake Proportioning Valve?

[ruppstang]

Do you know if power drum or disc brake?

IMHO it would have to be a disc car because the is no reason for a proportion valve on a power drum brake car, the pressure is the same front and back.

[Bob Gaines]

IMHO it would have to be a disc car because the is no reason for a proportion valve on a power drum brake car, the pressure is the same front and back.

I was trying to understand a reason for use . Given that the 67 ,68 ,and 69/70 use virtually the same proportioning valve I am at a loss to understand why it looks so different. Most other Ford brass assemblys like brake lines,typical proportioning valves ,distribution blocks etc. are metal stamped with engineering number in the brass . Maybe after market?

[sah62]

...and the mystery deepens. I have personally seen the C9OA-2B091-A engineering number on a cylindrical valve. Take a look at the attached picture and help me understand how the same engineering number might appear on a very different part!

Bob, it may look different as a function of Ford trying to reduce the number of service parts that could be used across car lines. The full-sized A-line cars (Galaxie etc.) used a proportioning valve that looks a lot like this one. Maybe Ford decided to make this part the service part for F-line cars, too.

[Bob Gaines]

...and the mystery deepens. I have personally seen the C9OA-2B091-A engineering number on a cylindrical valve. Take a look at the attached picture and help me understand how the same engineering number might appear on a very different part!

Bob, it may look different as a function of Ford trying to reduce the number of service parts that could be used across car lines. The full-sized A-line cars (Galaxie etc.) used a proportioning valve that looks a lot like this one. Maybe Ford decided to make this part the service part for F-line cars, too.

That my be it. It wouldn't be the first time Ford did that, make another part that fits a variety of applications that is.

[sah62]

OK, one thing is for sure - with a C9 engineering number this isn't a part designed for use during the 1967 model year.

[J_Speegle]

........... function of Ford trying to reduce the number of service parts that could be used across car lines. The full-sized A-line cars (Galaxie etc.) used a proportioning valve that looks a lot like this one. Maybe Ford decided to make this part the service part for F-line cars, too.

But that may not apply to the 67 part.

As for the C9 why wouldn't you just use the cylinder style part already in production as the service piece (smaller item that would fit in more spots) unless it was cheaper to make this odd ball shaped one.

Think we need to find some more bridges to reach the answer

[sah62]

Cheaper may be the answer, Jeff. The valves that appeared during the 1970 model year used the same basic internal parts as this block-shaped valve. It could be that this is what the manufacturers were moving to.

Keeping this on-topic to '67s, though: if folks could confirm the engineering numbers seen on cylindrical valves (pics would be nice, too) I'd greatly appreciate it.

[ruppstang]

There is a original with the part number.

Perhaps this design was developed because it was installed in the back of the car inline. The shape may not have been as important when it was moved under the distribution block. Just a possibility.

[sah62]

Thanks, that's a C7OA-C. Here's a cylindrical C9OA-A. Does anyone have a picture of a C7OA-A or C7OA-B?

[J_Speegle]

Just a thought

If this odd shaped one was meant to be a replacement  why is it designed and installed at the front (in the engine compartment)  and what takes the place of the one in the rear , since there is no additional fittings or item to take up the gap

Surely if there is a problem with the original factory (if that is what is going on) the idea was not to leave it in place once it was replaced by the other

[krelboyne]

I saw a huge clue that it can be a service replacement, in the photo of the instruction sheet for the NOS valve:

This valve is shaped different than valve it replaces ..... and requires the new included brake lines for Fairlane / Montego, Falcon / Comet.

1967- 1969 Mustang / Cougar - Form existing brake lines to accommodate new valve.

I have 3 examples of what I call the 'Texas' shaped control valve. Mine all show: SURF 315-7 or (166-7, 088-5) X-2B328-BB. My guess is that the 315-7 is the Julian Date followed by the year? 1967 and 1975?

We mostly have examples of the C7OA-2B091-C and C9OA-2B091-A. No other casting numbers found. IMHO, I believe that the date code is year,month,day.

For C7OA-2B091-C, I found BA20,BE26,BK09,BL29,CA18,CA23,CA30,CB06,CG02,CG29,CK16.
For C9OA-2B091-A, I found JC21,JE08.
 

[J_Speegle]

I saw a huge clue that it can be a service replacement, in the photo of the instruction sheet for the NOS valve:

This valve is shaped different than valve it replaces ..... and requires the new included brake lines for Fairlane / Montego, Falcon / Comet.

1967- 1969 Mustang / Cougar - Form existing brake lines to accommodate new valve.

Yes would think that you found the smoking gun. Still I have wonder how they addressed the gap (if you removed the factory valve) at the rear

I have 3 examples of what I call the 'Texas' shaped control valve. ...........

Very descriptive - like it

[sah62]

...and the mystery deepens. I have personally seen the C9OA-2B091-A engineering number on a cylindrical valve. Take a look at the attached picture and help me understand how the same engineering number might appear on a very different part!

Bob, it may look different as a function of Ford trying to reduce the number of service parts that could be used across car lines. The full-sized A-line cars (Galaxie etc.) used a proportioning valve that looks a lot like this one. Maybe Ford decided to make this part the service part for F-line cars, too.

Adding some new information: someone was kind enough to share an image of a replacement-style NOS C7OZ-2B091-B with yet another engineering number stamped on the body. X-2B328-BB; see the attached image.

[RoyceP]

Scott I bought one like that NOS on eBay in 2003. It was a service replacement part sold in the 1970’s. The kit came with a short hard line to adapt it in place of the cylindrical part which was original to my very early 1967 Cougar.

Has anyone seen a proportioning valve that looks like this used on 1967 Mustangs assembled prior to (approximately) February 1967? If so, I'm trying to learn if it is marked with an engineering number and if it was used on any other vehicles.

[CT428CJ]

I have a NOS one in the box.

I'll take some photos and post tomorrow.