GM Service Manual Online
For 1990-2009 cars only
  1. Turn the ignition switch to Lock.

  2. Object Number: 171984  Size: SH
  3. Press the brake pedal (1) several times to deplete the booster vacuum reserve.
  4. Hold the brake pedal with approximately 30 kg (66 lbs) of pressure.
  5. Measure the brake pedal-to-floor clearance. If the clearance is less than 80 mm (3.15 in), perform the following procedures:
  6. 4.1. Inspect the rear brake shoes and adjusters.
    4.2. Bleed the brake system. Refer to Hydraulic Brake System Bleeding .
    4.3. Check the brake booster pushrod length.