You can see that it's a pretty simple T connection to the front brakes at the valve. There would have to be a passage blocked very near the outlets. If it is defective, it's a bad defect. There a differential piston that slides to activate the warning light switch. My warning light will be on (if the key is on) when bleeding or the master cylinder is bad. But the piston has always corrected itself on my cars. It's possible to unscrew the plastic switch and check the position of the piston. No fluid will leak if you check it. The piston is sealed in with o-rings.

 

Plumbed correctly? If so, would suspect obstruction somewhere in line or flex hose.

 

Here's a pic of my 67. This setup is called the "very late 67"set up.
So you're saying the "front most port" which is for left front disc, at the block no fluid comes out?
Since the right side is right under left side poke a paperclip (or similar) into left side block port to feel if anything blocking it.
Worst case, There is access brass screw on cap at opposite end of the block. Don't remember if I ever did it, but with the cap off, the shuttle inside can be tapped or pushed back out. Then it's a clear shot to front of block to see thru for blockage.

 

Here's a pic of my 67. This setup is called the "very late 67"set up.
So you're saying the "front most port" which is for left front disc, at the block no fluid comes out?
Since the right side is right under left side poke a paperclip (or similar) into left side block port to feel if anything blocking it.
Worst case, There is access brass screw on cap at opposite end of the block. Don't remember if I ever did it, but with the cap off, the shuttle inside can be tapped or pushed back out. Then it's a clear shot to front of block to see thru for blockage.

Yep, that's exactly what I'm saying. No fluid is pushed out the port of the block for the driver side brakes. I pulled the line out and pumped the pedal and nothing came out of that port, not even a trickle. I'm tempted to just plug that port off and put a T in the one for the right side brakes to save me a headache of having to pull it out. If I end up pulling it out, i'll go with

. Going to tinker around with it some more today.

 

Wander if in the machining process they forgot to drill the port? Either that or blockage in the port. That is a cavity in there. If the right port has fluid, that left side port should as well.

 

I sure hope not....

 

Lord knows who manufactured the block. I suppose there's a REMOTE possibility (note I say "remote" as in "grasping at straws") that they made it like a GM block and the end of the shuttle is somehow blocking the port. I think, at this point in the game, I'd be pulling the switch to look at the position of the shuttle and, if moved forward be pulling the front line to see if I could push it back (may require loosening a rear line) and locking it in "neutral" and then seeing if I got fluid from the front.

 

So I was able to do exactly this. How exactly do you "lock it" in neutral?

 

Here's a video that will give the basic idea of how a differential valve works. The valve in the video is for a GM style valve that is often used in conversions. It's a bit different from Ford's, but a good example. If the piston has moved it should be simple to test the switch with a multimeter or look at the warning light on the dash if it's functional. It seems like you could remove the whole metering valve and shine a flashlight through the ports. There's probably nothing wrong with your new valve.

 

Quick question: Did you disconnect the hard line from the hose? I had a brand new rubber hose crimped closed at the fitting. Be careful with brake fluid around your paint as well. It will remove it.

 

My thought,
IF the shuttle was "blocking the left front port (which is front most port) you also wouldn't have any fluid coming out of right hand side port which is front bottom, which you said was ok. IF that shuttle was all the way forward, NO fluid would be coming out of either front port.
Poke insde that port to feel if any obstruction. Or as mentioned unscrew back cap and push shuttle out and inspect.

 

My thought,
IF the shuttle was "blocking the left front port (which is front most port) you also wouldn't have any fluid coming out of right hand side port which is front bottom, which you said was ok. IF that shuttle was all the way forward, NO fluid would be coming out of either front port.

That's assuming the cavity in the block is the same diameter as the shuttle. If there is room for fluid to flow AROUND the shuttle between the inlet and right (bottom) outlet but the shuttle is covering the orifice to the left front the symptoms would be as described. Without sawing the block in half it's hard to speculate.

 

The distribution block is simply there as a safety precaution. It's highly unlikely for a 67 style block to only have fluid to one wheel. The 68-70 is different and much more likely.

 

Just as a followup, someone on a Cougar forum was having a similar problem with the SD distribution valve; Problem Bleeding Brakes - Classic Cougar Community

 

Hmm, that tube has a common feed , I'd guess you'd then have NO fluid to either caliper, not just one. Me thinks

 

I gave up trying to get that new block to work. I went back with my old one and just cleaned up how I had my lines run so now it looks really nice and clean and my brakes work!!

 

You ditched the new distribution block that you got from NPD?
Your brakes worked to begin with....... just sayin'
And if you now have a non-adjustable proportioning valve, you actually went backwards in
vehicle dynamic performance AND cash.

ex-Global West GM
1991-1995

 

You ditched the new distribution block that you got from NPD?
Your brakes worked to begin with....... just sayin'
And if you now have a non-adjustable proportioning valve, you actually went backwards in
vehicle dynamic performance AND cash.

ex-Global West GM
1991-1995

Oldie but a goodie

 

I'd have to know why if me. You know it's the block you put in. If style i think it is, I'd open the back end of it, slide out the shuttle/plunger what ever you call it and inspect inside block

 

yeah, i plan on getting into that new valve, probably after the holidays. It's also leaking at one of the hardline inverted flare fittings for the rear proportional valve so I have that to deal with too.