Well I finally got a chance to look things over a little more. I climbed into the truck for the 1st time in 2 weeks and stepped on the brake pedal. It's still all the way up and hard as a rock. I pushed on the pedal pretty hard and started the engine. The pedal moved less than 1/2 inch down. Still hard. Checked level in MC. NO fluid loss. I then climbed underneath. I don't see a plug on the back of the Hydrovac unit anywhere. I asked Wifey to come out and step on the brake pedal when I said OK. I then took the line off the back of the hydrovac and told her to push the pedal down HARD. Brake fluid shot the entire length of the truck so there doesn't appear to be any restriction inside the unit itself. With her foot still on the floor, I re-connected the line, then topped off the MC. Took the truck down the gravel driveway and jammed the brakes as hard as I could, resulting in a slow coast to a stop.
