I noticed in another post of yours you spoke of blowing off the
vacuum caps on the carb as well as the plug on the booster.
Are you getting good vacuum to the booster?
Did you check the booster itself?
Are you sure its not holding?
At first I had a problem with pushing the front wheels even though
they were locked up.
I thought mine wasn't holding either till I had a friend watch.
Are the brake boosters the same 72 & 73.
Are these power brakes or manual and is the brake booster the
power assit unit?
By the way moved this topic to Tech Board.
Mines on top of the quarter stick.
I have heard of people putting it on the floor to the
left of the brake pedal.
Can you turn the knob so you can hold it with your thumb.