Jason,
To confirm the Hydrovac is working do the following test;
With the engine off (first start of the day). step down on the brake pedal (medium/hard pressure) and start the engine. As the truck builds vacuum you should feel the brake pedal fade away just a little bit. If it does then the hydrovac is working.
While replacing ALL of the steel lines did you replace the three rubber flex lines? They go bad from the inside out as well.
Be safe!
Mike B
