Put on a new master cylinder and blead the brakes well. Brake light stays on,car stops well but pedal still seems kinda soft. Is this normal on these Cougars? Can I reset the brake light ?
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The “seems kind of soft” is pretty subjective and hard to say but you should get a firm peddle. But the light not resetting may be due to the actuator being stuck. I have had some luck tapping on the proportioning valve near the switch. But key is getting them bled properly.
Did you bleed the master before putting it on? That makes the remaining bleeding process much easier. And sometimes you can chase those little air bubbles forever and not make headway if you bled the master on the car with the lines.
Thanks. Car does have disc front brakes and pedal just seems to go 1/3 of the way down before I get much brake then they feel fine. Blead them well and even took car to a brake shop and had them do it. Thanks for brake light info. 
Sounds like your distribution blocks internal valve is not centered and causing your switch to activate. It needs to be recentered. More than likely it is cutting off the flow to your rear brakes. Sometimes you can get it to recenter by opening a bleeder on the front brakes and have someone push the brake pedal rather quickly until the light goes out then release the pedal and close the bleeder. This recenters the valve. If that does not work you will need to remove the distribution block and rebuild it as the valve is frozen.
You may have to play around a little. The switch could be stuck either towards the front or the back side of the switch. When you bleed the brakes turn your key on watch the brake light push the pedal down with a bleeder open. When you reach the bottom if you feel a small click and the light flashes, you just moved the switch to the other end. You will than go to the other end of the car open bleeder go about 90% on the pedal close bleeder step on the pedal see if the light goes out. It may take some time to center it. You could also ckeck the manuel for instructions for resetting switch.
Hope that makes sence.
At the risk of disagreeing with the good Dr., I am relatively sure this is not possible and a fallacy, at least in the case of the 68/69 disc distribution block. The reason I say/know this is what I observed after a buddy suggested the same thing to me. Having rebuilt a number of these, I am very familiar with the shuttle configuration. It is necked down on both ends and so when it slides to the extremes of its travel, the fluid still has a way to get around the shuttle (since it is necked down). On the disc side there is even a groove cut into the end of the necked down part of the shuttle so as to avoid the line to DS side (which screws into the end of the block rather than under it as the other lines to the car do) being cutoff when the shuttle is at the end of its travel in that direction.
Regards,
Bob
I should know better than type technical information before my morning coffee! What I meat was it reduces the flow. Quoting from the shop manual “Should a failure of the rear brake system occur, hydraulic fluid pressure in the rear brakes system would drop. During brake pedal operation the fluid pressure build-up of the front brake system forces the valve to move toward the low pressure area, or toward the rear brake system oulet port. Movement of the differential valve forces the switch plunger upward over the tapered shoulder of the valve to close the switch”. As you pointed out the valve does not completely shut down the rear brakes but it does restrict the flow.
Thanks for checking up on me!
I should know better than type technical information before my morning coffee! What I meat was it reduces the flow. Quoting from the shop manual “Should a failure of the rear brake system occur, hydraulic fluid pressure in the rear brakes system would drop. During brake pedal operation the fluid pressure build-up of the front brake system forces the valve to move toward the low pressure area, or toward the rear brake system oulet port. Movement of the differential valve forces the switch plunger upward over the tapered shoulder of the valve to close the switch”. As you pointed out the valve does not completely shut down the rear brakes but it does restrict the flow.
Thanks for checking up on me!
I had a rather heated and extensive discussion with a very renowned fellow Cougar owner about the function of the above mentioned distribution/diverter valve concerning restricting the flow. If you blow a hose or wheel cylinder you can use the other side of the system to “limp home”.
And I believe the Ford service manual describes the procedure for re-centering the valve by opening a bleeder and depressing the brake pedal until the light goes out. I’ve done it and it works.
Disclaimer: The following is posted in the interest of technical discussion and understanding how the item under discussion actually works. The poster has no interest in one person being right over another, only what the facts are. Thank you. 
I suppose it is how you interpret the words, but I don’t get from them that any fluid flow is restricted under any condition (although I can see how the words “hydraulic fluid pressure in the rear brakes system would drop” could be interpreted that way). What I believe they are saying that because something happened in that circuit, the pressure dropped in it and the shuttle then moves because of the pressure differential. I do not get anything about a restriction from the words, nor when you examine the shuttle design/configuration. Take a look at one, you’ll see (and can see in my picture above) the necked down areas on both ends of the shuttle. Also look at the bore in the block, it is the size of the large diameter of the shuttle all the way through. So, regardless of where the shuttle is sitting, there is a path for fluid to go around it, by virtue of the necked down diameter areas being in the larger bore of the block. Further (and as I mentioned above), the disc end of the shuttle actually has a groove in it so that the port that the DS line connects to is not cut off from fluid flow when the shuttle happens to slide in that direction. Lastly, if you think about it, a restriction in one side (when the shuttle has moved to that side) would maike it very difficult/impossible to re-center the shuttle, the reason being is a restriction would restore pressure equalization to some extent. Pressure differential is what is required to move the shuttle, a restriction would counter a pressure differential upstream of the block.
Having said all that, if the larger diameter of the shuttle were to travel enough to block/obscure the line ports above/below it, a restriction would be created. However, because of the way the block/shuttle are designed, this does not occur, even at the extremes of shuttle travel one way or the other.
Regards,
Bob
Is there any way to tell which direction the shuttle needs to move? I am having this problem with my '67 and I can’t tell which way it needs to go to find the center. Bob, thanks for posting those great pics!
Absolutely! This might sound like a joke, but it isn’t. What I do is have someone step on the pedal, crack one of the rear screws and listen for the “plink” of the shuttle going toward the rear side, so now you know where the shuttle is located! I like to center the valve from the LF disc because I can stick a small punch down the block (with the switch out) and “catch” the shuttle to get it “kind of” centered at the same time I am opening the LF screw. So do that. Then, install the switch and see how well you centered (usually not well enough). Then open one of the rear screws slightly while someone is stepping lightly on the pedal while watching the light (chances are it is slightly off center to the front when you tried to “catch” it going rear to front). Have them call out to you the moment the light goes out - immediately tighten the screw you had open when they do. If the opening the rear doesn’t work, go to the front and try one of those keeping in mind to only open the screw slightly, not like when you were putting the shuttle to one side initially. Once you get the light to go out and the screw you had slightly open closed, have the person step hard on the pedal and make sure the light stays out. You may have to play a bit with how far you open the screw and/or how hard the person steps on the pedal to get the small amount of movement you are after here. If you hear the “plink” again, you have gone too far and need to start over from the beginning of these instructions.
How’s that sound? Hope it helps.
The only way that I have been successful in keeping the shuttle centered is by cutting a short piece of a small nail that fits into the groove and then keeping it under pressure until the brakes are completely bled and then removing the nail. Crude but effective.
There are a couple of tools available for the purpose as well:
https://www.musclecarresearch.com/brake-valve-tool
There is a plastic version too, not sure where I have run across that one.
Not that I know of…
Try opening a front bleeder, if it doesn’t work do the back.
You’ve got to push the pedal pretty hard to move the valve, watch the light as you push.
I suggested a way, see my previous post.