GM Service Manual Online
For 1990-2009 cars only
  1. Block the wheels.
  2. Start the engine.
  3. Charge the system to the air compressor governor cut-out point.
  4. Stop the engine.
  5. Apply a soap solution to cover the inflation valve.
  6. If any bubbles appear, install the valve core finger tightly and inspect the valve for leaks.
  7. If any leakage is still present, replace the inflation valve.
  8. Remove the wheel blocks.