GM Service Manual Online
For 1990-2009 cars only

Heater Inlet Hose Replacement L61

Removal Procedure


    Object Number: 878122  Size: SH
  1. Disconnect the negative battery cable.
  2. Drain the coolant. Refer to Draining Coolant.
  3. Position the approved coolant container under the vehicle below the heater hose connections to catch any coolant that may be trapped in the lines.

  4. Object Number: 893885  Size: SH

    Important: Green plastic rings may be found hanging on the heater pipe after hose removal. This is a manufacturing aid and should be discarded.

  5. If only one hose is being serviced, open the hose assembly clamp and remove.

  6. Object Number: 893896  Size: SH
  7. Remove the heater inlet hose from the heater core pipe by depressing the quick connect collar tab, located at 6 o'clock, and pulling the black collar toward the front of the vehicle.

  8. Object Number: 893986  Size: SH
  9. Pull the quick connector off of the heater core pipe

  10. Object Number: 893989  Size: SH
  11. Remove the heater outlet hose from the heater core pipe by depressing the quick connect collar tab, located at 6 o'clock, and pulling the white collar toward the front of the vehicle.
  12. Pull the quick connect off of the heater core pipe.

  13. Object Number: 893899  Size: SH
  14. Remove the heater core inlet hose to engine housing clamp and remove the hose.

  15. Object Number: 893904  Size: SH
  16. Remove the heater core outlet hose to thermostat housing clamp and remove the hose.

Installation Procedure


    Object Number: 893904  Size: SH

    Important: The heater inlet hose quick connect coupling collar is black. Heater outlet quick connect coupling collar is white.

    Important: The white line on the hoses should always be installed at the 12 o'clock position.

  1. Install the heater core outlet hose to thermostat housing at the rear of the engine.
  2. Position the heater core inlet hose to thermostat housing clamp at the 12 o'clock position.

  3. Object Number: 893899  Size: SH
  4. Install the heater outlet hose to thermostat housing at the left side of the housing.
  5. Position the heater outlet hose to thermostat housing clamp at the 12 o'clock position.

  6. Object Number: 893910  Size: SH
  7. Install the heater inlet quick connect to heater inlet pipe (closest to the drivers side). Holding the quick connect by the black collar, slide onto the heater pipe. When the quick connect engages the heater pipe bead, the collar will slide toward the front of the dash and lock into position.
  8. Verify proper engagement of the quick connect by attempting to pull the inlet hose off of the heater pipe.
  9. Install the heater core outlet quick connect to heater outlet pipe (closest to the passenger side). Holding the quick connect by the white collar, slide onto the heater pipe. When the quick connect engages the heater pipe bead, the collar will slide toward the front of the dash and lock into position.
  10. Verify proper engagement of the quick connect by attempting to pull the outlet hose off of the heater pipe.

  11. Object Number: 893885  Size: SH
  12. Install the heater hose assembly clamp, if removed.

  13. Object Number: 878122  Size: SH
  14. Connect the negative battery cable.
  15. Tighten
    Tighten the battery terminal bolts to 17 N·m (13 lb ft).

  16. Fill the cooling system. Refer to Coolant Replacement.

Heater Inlet Hose Replacement L81

Removal Procedure


    Object Number: 878122  Size: SH
  1. Disconnect the negative battery cable.
  2. Drain the coolant. Refer to Draining Coolant .
  3. Position the approved coolant container under the vehicle below the heater hose connections to catch any coolant that may be trapped in the heater hoses.

  4. Object Number: 893885  Size: SH
  5. Open the heater hose assembly to the manifold clamp.

  6. Object Number: 893896  Size: SH

    Important: Green plastic rings may be found hanging on the pipes after hose removal. These are manufacturing aids and should be discarded.

  7. Remove the heater core inlet hose from the heater core pipe by depressing the quick connect collar tab, located at the 6 o'clock position, and pulling the black collar towards the front of the vehicle and then pulling the quick connect off of the heater core pipe.

  8. Object Number: 893989  Size: SH
  9. Remove the heater core outlet hose from the heater core pipe by depressing the quick connect collar tab, located at the 6 o'clock position, and pulling the white collar toward the front of the vehicle and then pulling the quick connect off the heater core pipe.

  10. Object Number: 894612  Size: SH
  11. Remove the return hose to engine housing clamp and remove the return hose.
  12. Remove the heater core outlet hose to the engine coolant inlet housing clamp and remove the hose.

  13. Object Number: 894384  Size: SH
  14. Remove the heater inlet hose to the coolant bridge clamp and remove the hose.

Installation Procedure


    Object Number: 894384  Size: SH

    Important: The heater inlet hose quick connect coupling collar is black. The heater outlet quick disconnect coupling collar is white.

    Important: The white line on the hoses should always be installed at the 12 o'clock position. Install the heater hose into the manifold clamp but do not lock the clamp.

  1. Install the heater inlet hose to the coolant bridge and install the clamp at the 12 o'clock position.

  2. Object Number: 894612  Size: SH
  3. Install the outlet hose to the engine coolant inlet and install the clamp.
  4. Install the return line to the coolant bridge and install the clamp at the 2 o'clock position.

  5. Object Number: 893910  Size: SH
  6. Install the heater core inlet quick connect to the heater inlet pipe, closer to the driver's side. Holding the quick connect by the black collar, slide onto the heater pipe. When the quick connect engages the heater core pipe bead, the collar will slide towards the front of the dash and lock into position. A green paint band will be visible when the collar is properly positioned.
  7. Verify the proper engagement of the quick connect by attempting to pull the hose off of the heater pipe.
  8. Install the heater core outlet quick connect to the heater outlet pipe, closest to the passenger's side. Holding the quick connect by the white collar, slide onto the heater core pipe. When the quick connect engages the heater core pipe bead, the collar will slide towards the front of the dash and lock into position. A green paint band will be visible when the collar is properly positioned.
  9. Verify the proper engagement of the quick connect by attempting to pull the hose off of the heater pipe.

  10. Object Number: 893885  Size: SH
  11. With the hoses properly positioned, close the heater hose assembly to the manifold clamp.

  12. Object Number: 886658  Size: SH
  13. Connect the negative battery cable.
  14. Tighten
    Tighten the battery terminal bolts to 17 N·m (13 lb ft).

  15. Fill the cooling system. Refer to Coolant Replacement .
  16. Use fresh water to rinse away any coolant that was spilled during the service.