GM Service Manual Online
For 1990-2009 cars only

Hydraulic Booster Functional Test for Chevrolet Astro - 2WD 2000

With the ignition in the OFF position, apply the brake pedal several times to empty the accumulator. Apply the brake pedal using 180 N·m (40 lb) of force. Start the engine. The pedal should fall away and then push back against your foot.