GM Service Manual Online
For 1990-2009 cars only
  1. Disconnect the knock sensor wire harness retaining clips from the pipe.
  2. Remove the hose and clamp.

  3. Object Number: 64139  Size: SH
  4. Remove the engine coolant air bleed pipe bolts.
  5. Remove the engine coolant air bleed pipe and gaskets.

  6. Object Number: 64262  Size: SH
  7. Remove the gaskets from the pipe.
  8. Discard the gaskets.