GM Service Manual Online
For 1990-2009 cars only

Heater Outlet Hose Replacement Front Only System

Tools Required

    • J 43181 Heater Line Quick Connect Release Tool
    • J 38185 Hose Clamp Pliers

Removal Procedure

  1. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Remove the transmission. Refer to Transmission Replacement in Automatic Transmission - 4L60-E/4L65-E.
  3. Remove the generator. Refer to Generator Replacement in Engine Electrical.
  4. Remove the secondary air injection pump. Refer to Secondary Air Injection Pump Replacement in Engine Controls - 4.2L.

  5. Object Number: 735781  Size: SH
  6. Using the J 43181 disconnect the outlet hose from the heater core outlet tube (1).
  7. 5.1. Install the J 43181 to the outlet heater core hose.
    5.2. Close the tool around the outlet heater core hose.
    5.3. Firmly pull the tool into the quick connect end of the heater hose.
    5.4. Firmly grasp the heater hose. Pull the heater hose forward in order to disengage the hose from the heater core.
  8. Remove the heater outlet hose (3) from the heater core (1).

  9. Object Number: 735779  Size: SH
  10. Position the outlet heater hose clamp (6) at the water pump using J 38185 .
  11. Remove the heater outlet hose (7) from the outlet hose fitting.
  12. Remove the heater outlet hose.

Installation Procedure


    Object Number: 735779  Size: SH
  1. Install the outlet heater hose.
  2. Install the heater outlet hose (7) to the outlet hose fitting.
  3. Position the outlet heater hose clamp (6) at the outlet hose fitting using J 38185 .

  4. Object Number: 735781  Size: SH
  5. Install the heater outlet hose (3) to the heater core (1).
  6. Firmly push the quick connect onto the heater core hose until you hear an audible click.
  7. Install the secondary air injection pump. Refer to Secondary Air Injection Pump Replacement in Engine Controls - 4.2L.
  8. Install the transmission. Refer to Transmission Replacement in Automatic Transmission - 4L60-E/4L65-E.
  9. Install the generator. Refer to Generator Replacement in Engine Electrical.
  10. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.

Heater Outlet Hose Replacement Auxiliary System

Tools Required

    • J 43181 Heater Line Quick Connect Release Tool
    • J 38185 Hose Clamp Pliers

Removal Procedure

  1. Remove the coolant bypass valve. Refer to Coolant Bypass Valve Replacement .
  2. Remove the transmission. Refer to Transmission Replacement in Automatic Transmission - 4L60/4L65-E.

  3. Object Number: 735781  Size: SH
  4. Remove the heater outlet hose (3) from the heater core (1).

  5. Object Number: 871567  Size: SH
  6. Position the outlet heater hose clamp (6) at the water pump using J 38185 .
  7. Remove the heater outlet hose (7) from the outlet hose fitting.
  8. Remove the heater outlet hose.

Installation Procedure


    Object Number: 871567  Size: SH
  1. Install the outlet heater hose.
  2. Install the heater outlet hose (7) to the outlet hose fitting.
  3. Position the outlet heater hose clamp (6) at the outlet hose fitting usingJ 38185 .

  4. Object Number: 735781  Size: SH
  5. Install the heater outlet hose (3) to the heater core (1).
  6. Firmly push the quick connect onto the heater core hose until you hear an audible click.
  7. Install the transmission. Refer to Transmission Replacement in Automatic Transmission - 4L60/4L65-E.
  8. Install the coolant bypass valve. Refer to Coolant Bypass Valve Replacement .