GM Service Manual Online
For 1990-2009 cars only
  1. Have an assistant detect the actual leak point inside the vehicle.

  2. Object Number: 95572  Size: SH
  3. Apply an unrestricted water flow. Use a hose without a nozzle.

  4. Object Number: 293131  Size: SH
  5. Begin at the base of the suspected leak area. Move the water flow slowly upward.