Speedway motors has lots of different brake devices. Here's a proportioning valve.

Adjustable Proportioning Valve Block, Brake Distribution System

Here's a adjustable single valve.
Speedway Purple Proportioning Valve

 

That's my original plan. Tee the fronts and install an adjustable proportioning valve on the rear. The front and rear are using separate reservoirs and valves at the master cylinder, so the only safety I'm actually defeating is the brake light switch.

If it stops raining, I'm still going to try and re-bleed the front brakes while having the rod pulled out to see if it even makes any difference at all. I guess theres a reason why it's called the 'bleeder rod'. The manual states that in order to bleed the brakes properly, you must pull out the bleeder rod and ford has a metering valve bleeder tool. I'm guessing there must be a reason why they put this in the manual and have a tool specifically for it.

As a side note, can anyone direct me on how to adjust the rear drums? I can't seem to find a write up on it.

 

Get the "One way brake bleeder valves" at any auto parts store.
When I got my '86 the brake light was on, and found it to be the proportion valve.
Common fix was to do about 20 mph (some where disserted and safe) and Slam on the brakes, this "could re-set the valve"
Did not work for me, then saw an ad for some guy in town parting out one. Got the valve for $10 and it works fine.

The one way bleeder valves are your "one person" bleeding system. Loosen about 1/4 turn, go in the cab, slowly press the brake 2-3 times and fluid is pushed out and the check valve will not let air back in. close the valve, add more fluid to the master, and repeat a few timer per cylinder.....
I found the vac systems really to "Suck" (as in garbage"

 

I do have the check bleeders on all 4 wheels. I do not trust them as I've had 2 fail. 1 of them I installed and was already failed straight from the package.

 

Okay.. I held the bleeder rod out and had my son-in-law hold the brake pedal in. I definitely got a few air bubbles out and took it for a test drive. The brakes are way better than they were, but it seems like the rear is still engaging before the front brakes. The brake light is still on also.

I read somewhere that if the rear drums are too loose (shoes are further away from the drums), it can actually cause the rears to engage before the fronts. Not sure if that's what I'm experiencing now. Especially since the brake light is still on.

Going to try and have my son-in-law help to bleed all 4 corners to see if I can get this thing going!

 

That's sorta true, but perhaps not the most accurate way to describe it. I'd say loose rear shoes will delay the engagement of the front brakes. Same but different. Before a pitchfork wielding crowd comes after me, I've been trying to find the official documentation on the subject but am having only partial luck. The factory manual has some pretty pictures of the valve, but not much in the way of description.

I only have an '84 manual as a reference, so if different for '82, somebody please chime in.

From page 12-01-2:

"There are 3 functions of the pressure differential valve: It delays full effectiveness of the front brakes, it proportions pressure to the rear system, and it operates a warning system in case of malfunction."

I wish I could find the rest of my references for exactly how "it delays full effectiveness of the front brakes". I remember it well because I looked into this a couple of years ago after a brake failure. The following may have come from a general textbook and not an official Ford document, but it's still worth considering. It won't hurt to try and it may very well fix your problem.

Per my potentially faulty memory, drum brakes take a split second longer to start clamping down when compared to disc brakes. This is because the drum shoes retract further for required clearance when released. To get all four wheels to apply at the same relative time, one function of the proportioning valve is "delay full effectiveness of the front brakes". It does this by waiting to fully apply the front brakes until sensing the pressure in the rear lines is above a certain threshold, indicating the rear brakes are just starting to work. In a perfect world, the front and rear brakes then start working at the same time.

What does all this mean? Make sure your rear brakes are properly adjusted. Are they self-adjusting? (I think so, but am not positive.) If so, operating the parking brake is what takes up the slack, plus applying the foot brake while in reverse. Self-adjusters can also act up as they age, so I'd definitely check the adjustment of the rear brakes, as you were thinking. Could be the proportioning valve is responding correctly and there's nothing wrong with the valve itself.

When you said your front brakes aren't working, how did you determine this? Is it because the rear wheels lock up and skid? Or did you notice something else?

As far as bleeding the brakes, I FULLY agree with the other comments about a vacuum bleeder. It sorta works, but not completely. Something about the vacuum process seems to entrain tiny air bubbles throughout the brake fluid. Bleeding under pressure is the way to go. After ditching my vacuum bleeder, I went back to pressure bleeding by the Michael Jackson method (a man and a boy) with good results.

 

Yes bleed all 4 wheels with 2 people.
Also do it with the rod pulled out.

As for resetting the light, that valve moved to one side because lack of psi on one side. If you know what side it moved to take psi off the other,open bleeder, and hit the pedal using p s I to push it back to center.
Dave - - - -

 

Thanks for this info. I pretty much did stop using the vacuum bleeder. I just was not getting good results.

It was because the rear wheels would lock up and skid, so I was assuming the fronts were not activating. I'm thinking now that I need to adjust them. I'll try the emergency brake thing...

 

Have you looked at the rear shoes? The should be perfectly dry and a little dusty if anything. If they have had any rearend oil or brake fluid touch them, even though you cleaned them up they will tend to lock up when you apply the brakes.

Reading between the lines about the bleeder pin, it looks to me they are saying if you get a bunch of air in ahead of the proportioning valve, there is a chance you will not be able to overcome the spring and bleed the front brakes. Never had that problem though. Obviously if you are getting fluid out of the front brakes while bleeding, you don't need the "tool".

 

I prefer the Motive pressure bleeder. I can use it on all my vehicles.
I tried a set of the check-valve bleeders when I lived in VT and they quickly became rusted lumps. They make stainless versions but they are expensive and a set for all my vehicles would cost more than a Motive bleeder.

 

Ah, this changes everything. I'm glad I asked. For all we know, the front brakes may be operating just fine. It's time to investigate why the rear brakes are locking up. It may not have anything to do with the proportioning valve.

Do you normally use the parking brake? Lots of people don't, but setting the parking brake is part of how the rear drum self-adjusters operate. If you don't typically set the parking brake, your rear drums are likely in dire need of adjustment. If so, I'd suggest manually adjusting the drums before trying anything else.

After that, the next step would be to pull the drums for a look-see. I bet you'll find the shoes wet with brake fluid (leaking wheel cylinder) or oil (leaking axle seal). Either one could cause grabbing.

 

I'm pretty sure there was a new requirement in that era to include a warning system for brake problems. Dual braking systems were required in the 60s, which was a big safety improvement, as a single failure still left you with the other circuit. However, many drivers may not notice a gradual failure in one system, which unknowingly left you with a single system operating only half the brakes. The fix was a warning system.

Many manufacturers went with a fluid level sensor for the master cylinder reservoir. Apparently this met the legal requirements and also warned you ahead of time if you had a leak and were about to lose at least one brake system.

Ford went with a different idea. The light only comes on after a loss of pressure in one system, at which point you'd better hope the remaining circuit is up to snuff. If not, at least the bright red light on the dash offers a convenient distraction as you proceed to the crash site.

 

I may have steered you wrong with this last step. I forgot you still had the warning light illuminated. First take care of the hydraulic issue turning on the light. As previously suggested, this might be caused by the rear brakes being out of adjustment.

Once you get the hydraulic issue sorted, meaning all four brakes are clamping down as designed and the light is out, you might find the grabbing problem is fixed, too. If not, then it would be time to look inside the drums.

 

I will suggest to at least remove the drums and take a look; a leaking wheel cylinder could cause both the dash light to come on as well as grabby brakes.

 

Ah yes, a good point.

As a general rule, if I suggest something, wait a few minutes for somebody else to suggest a better course of action.

What do you think of checking the rear brake adjustment before pulling the drums? Is that moot because you're going to want to check for leaks inside the drums anyway?