GM Service Manual Online
For 1990-2009 cars

Removal Procedure

  1. Drain the cooling system. Refer to Cooling System Draining and Filling .
  2. Open the air inlet grille for the passenger compartment air filter.

  3. Object Number: 309505  Size: SH
  4. Remove the access panel nut near the passenger compartment air filter.
  5. Remove the access panel.
  6. If necessary, disconnect the heater core connection to provide extra clearances (discard assembly marker (1) if in place).

  7. Object Number: 153285  Size: SH
  8. Remove the following components from the hot water flow control valve:
  9. • The vacuum hose
    • The remaining hose clamps
    • The remaining hoses
  10. Remove the hot water flow control valve.

Installation Procedure


    Object Number: 153285  Size: SH
  1. Install the hot water flow control valve.
  2. Install the following hot water flow control valve components:
  3. • The hoses
    • The hose clamps
    • The vacuum hose

    Object Number: 309505  Size: SH
  4. Connect the heater core connection if disconnected (green assembly marker (1) is not needed).
  5. Install the access panel.
  6. Install the access panel nut until fully seated and not stripped.
  7. Close the air inlet grille for the passenger compartment air filter.
  8. Fill the cooling system. Refer to Cooling System Draining and Filling .