Bleeding a hydrovac without a pressure bleeder is going to be difficult. I'd recommend doing a flush with denatured alcohol first, to clean any dirt and debris out of the brake system, blow air pressure through all the lines and wheel cylinders to remove the alcohol, and once the system is clean and purged, catch the fluid you bleed out and recycle it. I've managed to go through a couple of quarts or more of brake fluid trying to get all the air out of a system with a remote booster downstream from the master cylinder. Since DOT 3 or 4 brake fluid is basically alcohol and glycerine if, a few drops of alcohol remain in the system they won't be a contaminant.
Jerry
