GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 DeVille 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Heater Inlet Pipe Replacement

Removal Procedure
  1. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Remove the air filter housing assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls-4.6L.
  3. Remove the exhaust gas recirculation (EGR) valve pipe. Refer to Exhaust Gas Recirculation Pipe Replacement in Engine Controls.
  4. Remove the heater hose from the heater inlet pipe. Refer to Heater Hoses Replacement .

    5. Object Number: 474771 Size: SH
  5. Remove the hold-down fastener (3) from the heater inlet pipe (2).
  6. Rotate the heater inlet pipe (2) in order to remove the pipe hold down bracket from the stud.
  7. Release the locking tabs on the coolant crossover side of the heater inlet pipe (2), and pull the heater inlet pipe (2) out of the heater pipe inlet adapter.
  8. Remove the heater inlet pipe (2) from the vehicle.

Installation Procedure

    Object Number: 474771 Size: SH
  1. Push the heater inlet pipe (2) firmly into the heater inlet pipe adapter (1) in order to engage the pipe (2) and lock it to the heater inlet pipe adapter (1).

    2. Pull out on the pipe (2) in order to ensure the pipe is properly engaged in the heater inlet pipe adapter (1).

  2. Rotate the heater inlet pipe (2) onto the hold down stud.
  3. Install the heater inlet pipe fastener (3) to the stud.

    4. Tighten
    Tighten the heater inlet pipe fastener (3) to 25 N·m (18 lb ft).

  4. Install the heater hose to the heater inlet coolant pipe (2). Refer to Heater Hoses Replacement .
  5. Install the EGR valve pipe. Refer to Exhaust Gas Recirculation Pipe Replacement in Engine Controls-4.6L.
  6. Install the air filter housing assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls-4.6L.
  7. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.