Subaru Coupes/Sedans/Wagons 1985-1996 Repair Guide

Heater Core

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REMOVAL & INSTALLATION




CAUTION
Properly disarm the air bag on vehicles equipped with the SRS system. Failure to do so can cause serious injury.

Justy

See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: Heater core and case assembly-Justy

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system into a suitable container.
  4.  
  5. Tag and disconnect the heater hoses from the heater core assembly.
  6.  
  7. Remove the right and left defroster ducts from the defroster nozzles. Pull the ducts from the heater case.
  8.  
  9. Disconnect the electrical wires from the fan switch and the blower motor.
  10.  
  11. Disconnect the air mix cable from the heater unit. Disconnect the mode cable from the heater unit. Tag each cable for identification before removing.
  12.  
  13. Remove the bolts that retain the heater unit to the instrument panel assembly.
  14.  
  15. Remove the glove box assembly for additional working space.
  16.  
  17. Disconnect the inside/outside air control cable from the blower assembly.
  18.  
  19. Remove the instrument panel assembly. Refer to Body & Trim for removal and installation steps.
  20.  
  21. Remove the heater unit retaining bolts. Remove the heater unit from the vehicle.
  22.  
  23. Remove the heater core cushion. Loosen the heater core holder and remove. Pull the heater core from the mounting and remove from the heater case.
  24.  

To install:
  1. Install the heater core into the heater case and install the core holder. Tighten the heater core holder and install the cushion.
  2.  
  3. Install the heater unit in the vehicle and install the mounting hardware.
  4.  
  5. Install the instrument panel assembly.
  6.  
  7. Connect the inside/outside air control cable to the blower assembly.
  8.  
  9. If removed, install the glove box door assembly.
  10.  
  11. Install the heater assembly-to-instrument panel bolts.
  12.  
  13. Connect the mode cable and air mix cables to the heater unit.
  14.  
  15. Connect the harness to the blower motor and fan switch.
  16.  
  17. Install the left and right defroster vents.
  18.  
  19. Connect the heater hoses.
  20.  
  21. Refill the cooling system.
  22.  
  23. Connect the negative battery cable.
  24.  
  25. Check for coolant leaks from the heater core and hose connections.
  26.  

Sedan, Coupe, Wagon and Brat
  1. Disconnect the negative battery cable.
  2.  
  3. Drain the coolant into a suitable container.
  4.  
  5. Tag and disconnect the heater hoses from the heater core pipes under the hood.
  6.  
  7. Remove the instrument panel from the vehicle. Refer to Body & Trim for removal and installation steps.
  8.  
  9. Remove the steering support beam.
  10.  
  11. Disconnect the door motor joint harnesses.
  12.  
  13. Remove the breather hose.
  14.  
  15. Discharge the A/C system using an approved recovery/recycling machine.
  16.  
  17. Remove the evaporator.
  18.  
  19. Remove the heater unit.
  20.  
  21. Remove the heater core from the case.
  22.  

To install:
  1. Install the heater in the case.
  2.  
  3. Install the heater case in the vehicle.
  4.  
  5. Install the evaporator assembly.
  6.  
  7. Recharge the A/C system using an approved recovery/recycling machine.
  8.  
  9. Connect the breather hose.
  10.  
  11. Connect the door joint harnesses.
  12.  
  13. Install the steering support beam.
  14.  
  15. Install the instrument panel.
  16.  
  17. Connect the heater hoses to the heater core.
  18.  
  19. Refill the cooling system.
  20.  
  21. Connect the negative battery cable.
  22.  
  23. Check for coolant leaks from the core and hose connections.
  24.  

Loyale and XT

See Figure 2

Click image to see an enlarged view

Fig. Fig. 2: Heater core and case assembly-Loyale and XT


CAUTION
Properly disarm the air bag on vehicles equipped with the SRS system. Failure to do so can cause serious injury.

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the engine coolant into a suitable container.
  4.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Tag and disconnect the heater hoses in the engine compartment.
  2.  
  3. Remove the rubber grommet around the heater hoses which run through the kick panel inside the car. The location is slightly above, and to the right of the accelerator pedal.
  4.  
  5. Remove the radio box or center console assembly.
  6.  
  7. Remove the instrument panel. Refer to Body & Trim for removal and installation steps.
  8.  
  9. If the car has a luggage shelf, remove it.
  10.  
  11. Disconnect the heater control cables and fan motor harness.
  12.  
  13. Disconnect the duct between the heater unit and blower assembly. Remove the right and left defroster nozzles.
  14.  
  15. Remove the mounting bolts at the top sides of the heater unit. Lift the heater core up and out on the heater unit.
  16.  
  17. Remove the heater core retaining connectors and remove the heater core from the mounting.
  18.  

To install:
  1. Install the heater core in the heater case and install the retaining hardware.
  2.  
  3. Install the heater unit and tighten the mounting bolts securely.
  4.  
  5. Connect the duct between the heater unit and blower assembly and install the left and right defroster nozzles.
  6.  
  7. Connect the fan motor harness and heater control cables.
  8.  
  9. Install the luggage shelf, if equipped.
  10.  
  11. Install the instrument panel, center console and radio box.
  12.  
  13. Install the heater hose rubber grommets and connect the heater hoses.
  14.  
  15. Fill the radiator with coolant. Connect the battery, start the engine and check for leaks at the core and hose connections.
  16.  

Impreza
  1. If equipped, discharge the A/C system using an approved recovery/recycling machine.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Drain the cooling system into a suitable container.
  6.  
  7. Tag and disconnect the heater hoses from the firewall.
  8.  
  9. Remove the center console box.
  10.  
  11. Remove the cup holder.
  12.  
  13. Remove the radio. Refer to the procedure in this section.
  14.  
  15. Remove the drivers side lower instrument trim panel, then disconnect the seat belt timer harness.
  16.  
  17. Remove the glove box.
  18.  
  19. Remove the bolts and lower the steering column.
  20.  
  21. Remove the steering column covers.
  22.  
  23. Remove the hood release handle.
  24.  
  25. Set the temperature control switch to MAX. COLD, and mode selector switch to the DEFROSTER position.
  26.  
  27. Unfasten the following connectors:
    1. 1-15 pin grey
    2.  
    3. 2-5 pin natural
    4.  
    5. 3-20 pin white
    6.  
    7. 4-20 pin blue
    8.  
    9. 5-12 pin black
    10.  
    11. 6-8 pin natural
    12.  
    13. 7-1 pin blue
    14.  
    15. 8-6 pin black
    16.  
    17. 9-20 pin natural
    18.  

  28.  
  29. Remove the instrument panel nuts and bolts.
  30.  
  31. Remove the defroster grilles.
  32.  
  33. Pull the instrument panel outward carefully, disconnect the speedometer cable from the instrument cluster and remove the instrument panel.
  34.  
  35. Remove the steering support beam.
  36.  
  37. Disconnect the discharge pipe, suction pipe and grommets from the evaporator. Cap the hoses to prevent moisture from entering the system.
  38.  
  39. Disconnect the harness from the evaporator.
  40.  
  41. Disconnect the drain hose from the evaporator.
  42.  
  43. Remove the mounting nut, bolt and evaporator.
  44.  
  45. Remove the bolt, nuts and the heater unit.
  46.  
  47. Separate the heater unit housing and remove the heater core.
  48.  

To install:
  1. Install the heater core into the case, and assemble the heater unit.
  2.  
  3. Install the heater unit. Attach the retainer bolts, and tighten the bolt and nuts to 6 ft. lbs. (8 Nm).
  4.  
  5. If equipped with A/C perform the following:
    1. Install the evaporator.
    2.  
    3. Connect the drain hose to the evaporator case.
    4.  
    5. Connect the harness to the evaporator.
    6.  
    7. Connect the discharge pipe, suction pipe and grommets to the evaporator.
    8.  

  6.  
  7. Install the steering support beam.
  8.  
  9. Position the instrument panel and connect the speedometer cable.
  10.  
  11. Install the instrument panel and ensure it engages the 3 body clips.
  12.  
  13. Install the defroster grille.
  14.  
  15. Install the instrument panel mounting bolts and nuts.
  16.  
  17. Connect the wire harnesses disconnected during removal.
  18.  
  19. Connect the temperature control cable and mode selector cable to the link.
  20.  
  21. Install the hood release handle.
  22.  
  23. Position the steering column and install the mounting bolts.
  24.  
  25. Install the center instrument panel console.
  26.  
  27. Install the glove box.
  28.  
  29. Connect the seat belt timer harness, then install the driver lower instrument trim panel.
  30.  
  31. Install the radio.
  32.  
  33. Install the center console.
  34.  
  35. Install the cup holder.
  36.  
  37. Connect the heater hoses to the firewall.
  38.  
  39. Connect the negative battery cable.
  40.  
  41. Fill and bleed the cooling system.
  42.  
  43. If equipped, evacuate and charge the A/C system using an approved recovery/recycling machine.
  44.  
  45. Check for coolant leaks at the core and hose connections.
  46.  

Legacy

See Figure 3

Click image to see an enlarged view

Fig. Fig. 3: Heater core and case assembly-Legacy

  1. Disconnect the negative battery cable.
  2.  
  3. Disarm the air bag, if equipped.
  4.  
  5. Drain the engine coolant into a suitable container.
  6.  
  7. In the engine compartment, tag and disconnect the heater hoses at the firewall. Plug the openings to prevent spillage inside the vehicle.
  8.  
  9. Remove the front side sill cover and disconnect the air bag connector (AB9) and (AB10).
  10.  
  11. Remove the shift knob, if equipped with a manual transaxle.
  12.  
  13. Remove the center console assembly.
  14.  
  15. Remove the front pillar lower trim panel from the body.
  16.  
  17. Remove the trim panel that secures the hood release cable in place.
  18.  
  19. Remove the trim cover below the steering column.
  20.  
  21. Remove the instrument panel, disconnecting the speedometer cable and wire harnesses. Refer to Body & Trim for removal and installation steps.
  22.  
  23. Remove the glove box and back panel assembly.
  24.  
  25. Disconnect the blower motor harness.
  26.  
  27. Remove the bolts and lower the steering column. Tag and disconnect the necessary wire harnesses.
  28.  
  29. Disconnect the temperature control cable from the link of the heater case.
  30.  
  31. Remove ash tray, radio and temperature control unit from the dash.
  32.  
  33. Disconnect the dashboard harness connectors.
  34.  
  35. Remove the dashboard mounting bolts.
  36.  
  37. Remove the front defroster grille and 2 mounting bolts.
  38.  
  39. Remove the dashboard from the body. Refer to Body & Trim for removal and installation steps.
  40.  

When storing the removed dashboard, place in an upright position on a workbench or floor.

  1. Remove the steering support beam.
  2.  
  3. Properly evacuate the A/C refrigerant from the system using an approved recovery/recycling machine.
  4.  
  5. Disconnect the discharge pipe, suction pipe and grommets. Cap the openings of the A/C pipes to prevent contamination of the system.
  6.  
  7. Disconnect the harness from the evaporator.
  8.  
  9. Disconnect the drain hose.
  10.  
  11. Remove the evaporator unit mounting nut and bolt, remove the evaporator unit.
  12.  
  13. Remove the heater unit and separate the case halves. Remove the heater core from the heater unit.
  14.  

To install:
  1. Install the heater core into the heater unit. Connect the case halves. Install the heater unit to the vehicle.
  2.  
  3. Install the evaporator unit and secure.
  4.  
  5. Connect the drain hose and the harness to the evaporator.
  6.  
  7. Connect the grommets, suction pipe and discharge pipe to the evaporator. Be sure to use new O-rings for the A/C connections
  8.  
  9. Install the center support beam.
  10.  
  11. Install the dashboard to the body. Push the 2 pins into the grommets on the body panel and set the clips located at both inside ends of the instrument panel onto the body side.
  12.  
  13. Install the 2 mounting bolts at the front defroster grille and install the grille.
  14.  
  15. Install the dashboard mounting bolts.
  16.  
  17. Connect the dashboard harnesses.
  18.  
  19. Install the temperature control unit, radio and ashtray to the dash.
  20.  
  21. Connect the temperature control cable to the link of the heater case.
  22.  
  23. Raise the steering column and install the mounting bolts. Connect the wiring harnesses.
  24.  
  25. Connect the blower motor harness.
  26.  
  27. Install the glove box back panel and the glove box assembly.
  28.  
  29. Install the instrument panel, connecting the speedometer cable and harnesses.
  30.  
  31. Install the cover below the steering column.
  32.  
  33. Install the trim panel that secures the hood release cable.
  34.  
  35. Install the front pillar lower trim panel to the body.
  36.  
  37. Install the center console.
  38.  
  39. If removed, install the shift knob.
  40.  
  41. Connect the air bag connectors (AB9) and (AB10) and install the front side sill cover.
  42.  
  43. Using new clamps, connect the heater hoses to the heater core.
  44.  
  45. Connect the negative battery cable.
  46.  
  47. Fill the cooling system with coolant.
  48.  
  49. Properly charge the A/C system, using an approved recovery/recycling machine.
  50.  
  51. Run vehicle to normal operating temperature and check for leaks. Check the heating and A/C system for proper operation.
  52.  

SVX
  1. Disconnect the negative battery cable.
  2.  
  3. Disarm the air bag.
  4.  
  5. Drain the cooling system into a suitable container.
  6.  
  7. Tag and disconnect the heater hoses from the heater core in the engine compartment.
  8.  
  9. Remove the center console box assembly.
  10.  
  11. Remove the front pillar upper trim.
  12.  
  13. Remove the radio grounding wire.
  14.  
  15. Remove the remote controlled rearview mirror switch and internal bolt.
  16.  
  17. Remove the lower trim cover by removing the clips and bolts.
  18.  
  19. Disconnect the air bag harness at the harness spool.
  20.  
  21. Remove the plastic trim caps from both ends of the instrument panel, and remove the bolts.
  22.  
  23. Remove, tag and disconnect the instrument panel switches.
  24.  
  25. Remove the visor by removing the retainer screws. Disconnect the clock harness.
  26.  
  27. Remove the combination switch assembly.
  28.  
  29. Remove the glove box assembly.
  30.  
  31. Disconnect the instrument and body harnesses, as well as the antenna lead.
  32.  
  33. Cover the automatic transaxle select lever with cloth to avoid damage, if equipped with an automatic transaxle.
  34.  
  35. Remove the instrument panel by pulling it forward. Refer to Body & Trim for removal and installation steps.
  36.  
  37. Remove the steering support beam.
  38.  
  39. Disconnect the door motor joint harnesses (mode, air mix door and sensor) from the heater unit.
  40.  
  41. Remove the aspirator hose.
  42.  
  43. Remove the evaporator.
  44.  
  45. Remove the heater unit.
  46.  
  47. Remove the heater core from the case.
  48.  

To install:
  1. Install the heater core to the heater unit, and install the case assembly.
  2.  
  3. Install the evaporator and the evaporator hose.
  4.  
  5. Connect the door motor joint harnesses.
  6.  
  7. Install the steering support beam.
  8.  
  9. Install the instrument panel and connect the harnesses and antenna leads.
  10.  
  11. Install the glove box and retainer screws.
  12.  
  13. Install the combination meter.
  14.  
  15. Connect the clock harness.
  16.  
  17. Install the instrument panel switches, attaching the harnesses to each.
  18.  
  19. At the ends of the instrument panel, install the bolts and trim covers.
  20.  
  21. Install the 2 screws to the left and right sides.
  22.  
  23. Connect the air bag harness at the harness spool.
  24.  
  25. Install the panel lower cover.
  26.  
  27. Install the lower cover (six clips and 3 connectors).
  28.  
  29. Install the internal bolt and the remote controlled mirror switch.
  30.  
  31. Connect the radio grounding wire.
  32.  
  33. Install the front pillar upper trim.
  34.  
  35. Install the center console box.
  36.  
  37. Connect the heater hoses.
  38.  
  39. Fill the cooling system with coolant, check for leaks.
  40.  
  41. Connect the negative battery cable.
  42.  

 
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