Proportioning Valve Keeps Tripping?

[KyleSeal]

UPDATE 4/18

Since my last update, I have bench bled the master (again), replaced the rear brake hard lines and the single soft line, and cleared the tee of debris.
The rear lines had some junk, nothing significant, and the tee had some as well. The rear hose flowed fluid about as much as I would say the new one does. Was this a problem? Maybe, but either case, the hose was 5 years or more old, and the lines were beginning to strip on the line nuts. So not regretting I did those in any capacity.

These made no impact on the outcome.

I still have zero pedal.

I checked the clearance for the push rod from the booster to the MC, and it moves immediately when pedal input is applied, and moves smoothly.

For S&G I adjusted the pushrod WAY out to preload the brakes, see if I could even stop the trucks rear end while in the air, it took 5+ pedal pumps to stop it, but once stopped it did not allow the wheels to free spin in gear again, as if they were locked on. I did not apply throttle to see if it would do anything.

This is honestly the most response Ive gotten from these brakes, and I still have no idea of the operation of the front brakes as I havent had enough confidence to even allow the truck to move under power.

So, next I will install block off fittings on the master to see if I can have any pedal when flow is 100% sealed.

If this master is bad, I may have to move to some sort of Wilwood or something. I would prefer not to, as it will not fit the trucks looks whatsoever, but it may be my only option at this point.