budget 258 rebuild

Yep, that's a fact.  I used a needle nose vise grip to hold it up, tiny little plunger.

Probably more accurately called the metering valve or combination valve, it's only on disc/drum combo cars, at least back in 1976...I don't have a TSM to ref for your year.  The purpose of the valve is to delay full front disc pressure until the rear brake shoes make contact with the drums.  You hold it out while bleeding the front brakes, and it only needs to move out 0.09 inches minimum.

TheBirdman wrote: I didnt have time to closely look at the proportioning valve, but with my quick glance o couldnt see any levers or pins on it. What is this supposed to look like? Anyone got a picture?

The proportioning valve mounted near the rear axle on the frame rail will not have this because, well, it's a proportioning valve, not a metering valve. 
The metering valve holds up the application of the front brakes until the rear brakes build enough pressure to overcome the brake shoe return springs.
So you can't bleed the fronts unless you hold the pin out.
A proportioning valve won't interfere with bleeding.

Birdman -- I have a breather cap in the front hole, the rear hole I have the standard 4.0L PCV hose on. On the Renix 4.0L the front hole in the VC pulls from the air breather. The rear hole in the 4.0L VC should have a baffle under it, which keeps it from sucking oil and helps regulate air flow... along with that little tube. If you don't have a baffle, it really doesn't matter which hole you have the valve in and which the breather.

Eagles don't use a metering valve. The metering valve holds off the front brakes until 200 psi is in the braking system. It takes about that to overcome the springs in drum brakes. Theoretically, this meant all four wheels would brake at the same time. Metering valves were used only 5-6 years in the 70s. One of those "sounds good" ideas that practically makes so little difference it's not worth the effort. Hence you no longer see them used after 79-80 or so. Most 80s cars don't even use a proportioning valve -- late model Eagles don't, IIRC. If the front and rear brakes are sized correctly it's not needed. Some cars, like the Spirit and Eagle SX/4, used them through the end of production. Those are a lot lighter in the rear than the longer wheelbase cars and IIRC they use the valve instead of smaller brakes/wheel cylinders than their longer, heavier brethren. Cheaper to use the valve on them rather than smaller brakes.

Alright, I found the problem. I bled the brakes again, and I got a whole lot of brown crap and bubbles out of the rear brakes. Farna, youre right about 83 eagles not having a metering valve, I searched all over for it. After that, I jacked up the rear and manually adjusted the drums. Turns out last time I adjusted them, the rust was causing me to think they were starting to drag, and as a result the adjusters were a good 2 turns out from making contact. Now that most of the rust was worn off, I was able to get them tight, backed them off a little under a turn, and now the brakes work great. Sometimes they need a little double pump to get real tight, but I cleaned up the automatic adjusters so that should get better over time.