Move the bar to the side you want to increase pressure.
The 1/8" side play at the clevises is ESSENTIAL. Masters will not stroke right without out. I know ALL about this, chased a soft pedal for 3 years and 2 masters diagnosed as bad by two different mechanics. One of whom put it back together without the side play. Go to 1:10
https://www.youtube.com/watch?v=ZYK4VEOae6w
https://www.youtube.com/watch?v=NzIMlPEdtD0
EDIT: This is not Gary's setup. This applies to Wilwood pedal box with dual masters and balance bar.