Proportioning Valve Keeps Tripping?

[KyleSeal]

Originally Posted by 425HP409

Some service manuals said to lightly tap the caliper with a hammer to dislodge any small air bubbles that may be clinging to the caliper wall. This could be your pressure differential problem. This was in the textbook that I used when I taught at a trade school.

Originally Posted by Rust_never_sleeps

If there's air it's in the rear, and those are drums IIUC.
Could still be air in those wheel cylinders somehow, but I don't know if it can hide the way it might in a caliper.

I would consider air in the rear or front but given Ive done so much bleeding (literally gallons), if theres trapped air it at this point is a permanent resident

So my train of thought is this:
My proportioning valve is no longer biasing to the front or rear, which indicates a internal fault in the prop valve.
Given the red brake light no longer persists, but the pedal is far weaker than it should be, I would imagine an issue before the proportioning valve exists, which would indicate the master cylinder or booster has failed.
Hopefully I will be putting this theory to the test here this upcoming week.