Ever had self adjusting brakes overtighten?
I adjust until i hear them rub. Not feel them drag. And i let the adjusters do their job. I periodically clean,lubricate adjusters to keep them working.
To be honest, most vacuum brake bleeders suck.
I made a brake pedal hold down and do the entire process myself.
Press pedal,block it, go back and open bleeder. Repeat. Lots of back and forth but no helper required.