GM Service Manual Online
For 1990-2009 cars only

Heater Hoses Replacement Inlet

Removal Procedure

Tools Required

J 38723 Heater Line Quick Connect Separator


    Object Number: 318393  Size: SH
  1. Remove the gas mass sensor/mixture control valve (GMS/MCV) and mounting bracket. Refer to Gas Mass Sensor/Mixture Control Valve and Mounting Bracket Replacement in Engine Controls of the C/K Bi-Fuel Supplement.
  2. Remove the engine coolant. Refer to Draining and Filling Cooling System in the C/K Truck Service Manual.
  3. Disconnect the inlet hose from the generator bracket.
  4. Disconnect the inlet hose from the fender clips.
  5. Remove the clamps at the tee fitting.
  6. Disconnect the tee fitting from the inlet hose.
  7. Disconnect the inlet hose from the heater core.
  8. Disconnect the inlet hose section from the heater core.
  9. Push the inlet hose into the connector.
  10. Insert the J 38723 or equivalent into the connector to release the locking tabs.
  11. Pull the retainer and the hose from the heater inlet connector.
  12. Inspect the O-ring sealing surface on the hose/pipe.
  13. • If replacing the hose, it must be cut to allow for installation of the tee fitting. Cut the inlet hose 38 cm (15 in) from the heater core end of the hose.
    • If replacing the heater inlet connector, remove the retainer from the hose. Discard the retainer, as the replacement connector is equipped with a retainer.
    • If replacing the hose, remove the retainer from the hose and reinsert the hose into the connector.
    • If reusing the hose and the connector, the retainer can remain in place on the hose.

Installation Procedure


    Object Number: 318393  Size: SH
  1. Push the hose into the connector until the retainer tabs lock.
  2. Pull back on the hose to check for proper engagement.
  3. Connect the inlet hose section to the heater core.
  4. Connect the inlet hose clamp to the heater core.
  5. Connect the tee fitting to the inlet hose.
  6. Install the clamps at the tee fitting.
  7. Connect the inlet hose to the fender clips.
  8. Install the engine coolant and check the system for leaks. Refer to Draining and Filling Cooling System in the C/K Truck Service Manual.
  9. Install the GMS/MCV and mounting bracket. Refer to Gas Mass Sensor/Mixture Control Valve and Mounting Bracket Replacement in Engine Controls of the C/K Bi-Fuel Supplement.