GM Service Manual Online
For 1990-2009 cars only
  1. Check for a cracked master cylinder body or check for brake fluid around the master cylinder.
  2. • A leak is present if there is more than a drop of fluid.
    • A damp condition is not abnormal.
  3. Check for binding brake pedal linkage or for incorrect power brake booster pushrod clevis adjusted length.
  4. Check for brake fluid contamination within the system if both of these are satisfactory.
  5. Disassemble all the components if brake fluid contamination is suspected.
  6. Replace all swelled rubber components.
  7. Flush the brake system.