Hard (power) brake pedal

So got the steering box rebuilt and new exhaust. Boiled, soda blasted, and rebuilt the AVS and now I'm on the brakes.

I replaced everything on the brake system except the power booster and am using synthetic brake fluid.

It seems the power booster isn't boosting. The pedal is hard to the point I don't trust them.

I've gotten lots of good advice here on other projects so I'm hoping y'all can help me with this.

Thanks