How to replace heater core on chevy silverado pickup 1500

Removal & Installation

1. Disconnect the negative battery cable.
2. Drain the engine cooling system into a clean container for reuse.
3. Disconnect the heater hoses from the heater core.
4. Remove the instrument panel storage compartment.
5. Disconnect the electrical connectors, as necessary, that may be in the way.
6. Remove the center floor air distribution duct.
7. Remove the hinge pillar trim kick panels.
8. Remove the blower motor cover screws and the cover.
9. Remove the blower motor screws and the blower motor.
10. Remove the steering wheel and the steering column (standard & tilt).
11. Remove the instrument panel fasteners and pull the instrument panel back far enough to gain access to the heater assembly.
12. While holding the heater assembly against the firewall, remove the screw located on the interior side near the evaporator pipe, if equipped.
13. In the engine compartment, remove the 4 heater assembly-to-chassis screws and the 2 heater assembly-to-chassis nuts.
    
    NOTE

    Removal of the heater assembly may require the help of an assistant.
    
    
14. Remove the 7 heater cover-to-heater assembly screws and the cover.
15. Remove the heater core from the heater assembly.
    
    
    

    

    Fig. View of the front heater assembly

    
    
    
    

    

    Fig. Location of the front heater assembly-to-chassis fasteners

To install:

1. Install the heater core to the heater assembly.
2. Install the heater cover and the 7 heater cover-to-heater assembly screws.
   
   NOTE

   Installation of the heater assembly may require the help of an assistant.
   
   
3. In the engine compartment, install the 4 heater assembly-to-chassis screws and the 2 heater assembly-to-chassis nuts. Torque the screws to 17 inch lbs. (1.9 Nm) and the nuts to 25 inch lbs. (2.8 Nm).
4. While holding the heater assembly against the firewall, install the screw located on the interior side near the evaporator pipe, if equipped. Torque the screw to 97 inch lbs. (11 Nm).
5. Install the instrument panel and the instrument panel fasteners.
6. Install the steering column (standard & tilt) and the steering wheel.
7. Install the blower motor and the blower motor screws.
8. Install the blower motor the cover and the cover screws.
9. Install the hinge pillar trim kick panels.
10. Install the center floor air distribution duct.
11. Connect the electrical connectors that were disconnected.
12. Install the instrument panel storage compartment.
13. Disconnect the heater hoses to the heater core.
14. Refill the engine cooling system.
15. Connect the negative battery cable.
16. Run the engine to normal operating temperatures; then, check the climate control operation and check for leaks.

NOTE

This procedure requires the use of J 43181 Quick Connect Connector Removal Tool or equivalent.

1. Drain the engine cooling system into a clean container for reuse.
2. Remove or disconnect the following:
   
   
   Negative battery cable

   Air conditioning refrigerant, using the proper equipment
   
   
3. Using the J 43181 or equivalent quick connect tool, disconnect the inlet heater hose from the heater core.
   1. Install the tool to the heater core pipe.
   2. Close the tool around the heater core pipe.
   3. Firmly pull the tool into the quick connect end of the heater hose.
   4. Firmly grasp the heater hose. Pull the heater hose forward in order to disengage the inlet hose from the heater core.

   
   
4. Disconnect the surge tank outlet hose from the heater core using tool J 43181.
5. Remove or disconnect the following:
   
   
   Accumulator

   Instrument panel carrier

   HVAC module drain hose

   Electrical harnesses and the ground connections from the HVAC module

   Retaining nuts and bolts and HVAC module

   Screws from the heater core cover

   Cover from the HVAC module

   Heater core cowl gasket from the heater core

   Heater core from the HVAC module assembly
   
   

   

   Fig. Remove the nuts (4), bolts (3), then remove the HVAC module (2) from the vehicle (1)
   
   

To install:

1. Install or connect the following
   
   
   Heater core to the HVAC module

   Heater core cowl gasket

   HVAC module cover and secure with the retaining screws

   HVAC module into position. Torque the nuts to 90 inch lbs. (8 Nm) and the bolts to 35 inch lbs. (4 Nm).

   Electrical connectors to the module

   Instrument panel carrier

   Accumulator

   Hoses to the heater core. Firmly push the hoses on until you hear an audible -click- to be sure they are properly seated.

   Negative battery cable.
   
   
2. Refill the engine cooking system. Recharge the A/C system, using the proper methods and equipment.
3. Run the engine to normal operating temperatures; then, check the climate control operation and check for leaks.

1. Drain the engine cooling system into a clean container for reuse.
2. Remove or disconnect the following:
   
   
   Negative battery cable

   Heater hoses from the heater core

   Temperature control cable from the heater case assembly

   Disconnect the mode control cable from the heater case assembly

   Instrument panel carrier to provide access to the heater case assembly

   Electrical connectors that may interfere with the heater case assembly removal

   Heater case assembly-to-chassis screws/nuts and the assembly. Place the heater case assembly on a bench.

   Heater core cover screws

   Heater core from the heater case
   
   

   

   

   Fig. View of the heater case assembly-Sierra & Silverado

   
   
   

   

   

   Fig. View of the heater core-Sierra & Silverado
   
   

To install:

1. Install or connect the following:
   
   
   Heater core to the heater case

   Heater core cover screws and tighten to 14 inch lbs. (1.6 Nm)

   Heater case assembly and the assembly-to-chassis screws, then, tighten the screws to 35 inch lbs. (4 Nm) and the nuts to 80 inch lbs. (9 Nm)

   Electrical connectors, as necessary

   Instrument panel carrier

   Mode control cable to the heater case assembly

   Temperature control cable to the heater case assembly

   Heater hoses to the heater core

   Negative battery cable.
   
   
2. Refill the engine cooking system.
3. Run the engine to normal operating temperatures; then, check the climate control operation and check for leaks.

1. Disconnect the negative battery cable.
2. Drain the engine cooling system into a clean container for reuse.
3. Disconnect the heater hoses from the heater core.
4. Disconnect the temperature control cable from the heater case assembly.
5. Disconnect the mode control cable from the heater case assembly.
6. Remove the instrument panel carrier to provide access to the heater case assembly.
7. Disconnect any electrical connectors that may interfere with the heater case assembly removal.
8. Remove the heater case assembly-to-chassis screws/nuts and the assembly.
9. Place the heater case assembly on a bench and remove the heater core cover screws.
10. Remove the heater core from the heater case.
    
    
    

    

    Fig. View of the heater case assembly -Chevy/GMC Silverado

    
    
    
    

    

    Fig. View of the heater core-Chevy/GMC Silverado

To install:

1. Install the heater core to the heater case.
2. Install the heater core cover screws and tighten to 14 inch lbs. (1.6 Nm).
3. Install the heater case assembly and the assembly-to-chassis screws, then, tighten the screws to 35 inch lbs. (4 Nm) and the nuts to 80 inch lbs. (9 Nm).
4. Connect any electrical connectors that may have been disconnected.
5. Install the instrument panel carrier.
6. Connect the mode control cable to the heater case assembly.
7. Connect the temperature control cable to the heater case assembly.
8. Connect the heater hoses to the heater core.
9. Connect the negative battery cable.
10. Run the engine to normal operating temperatures; then, check the climate control operation and check for leaks.

1. Drain the engine cooling system into a clean container for reuse.
2. Remove or disconnect the following:
   
   
   Negative battery cable

   Heater hoses from the heater core

   Temperature control cable from the heater case assembly

   Disconnect the mode control cable from the heater case assembly

   Instrument panel carrier to provide access to the heater case assembly

   Electrical connectors that may interfere with the heater case assembly removal

   Heater case assembly-to-chassis screws/nuts and the assembly. Place the heater case assembly on a bench.

   Heater core cover screws

   Heater core from the heater case
   
   

   

   

   Fig. View of the heater case assembly

   
   
   

   

   

   Fig. View of the heater core
   
   

To install:

1. Install or connect the following:
   
   
   Heater core to the heater case

   Heater core cover screws and tighten to 14 inch lbs. (1.5 Nm)

   Heater case assembly and the assembly-to-chassis screws, then, tighten the screws to 35 inch lbs. (4 Nm) and the nuts to 80 inch lbs. (9 Nm)

   Electrical connectors, as necessary

   Instrument panel carrier

   Mode control cable to the heater case assembly

   Temperature control cable to the heater case assembly

   Heater hoses to the heater core

   Negative battery cable.
   
   
2. Refill the engine cooling system.
3. Run the engine to normal operating temperatures; then, check the climate control operation and check for leaks.

1. Drain the engine cooling system into a clean container for reuse.
2. Remove or disconnect the following:
   
   
   Negative battery cable

   Heater hoses from the heater core

   Temperature control cable from the heater case assembly

   Disconnect the mode control cable from the heater case assembly

   Instrument panel carrier to provide access to the heater case assembly

   Electrical connectors that may interfere with the heater case assembly removal

   Heater case assembly-to-chassis screws/nuts and the assembly. Place the heater case assembly on a bench.

   Heater core cover screws

   Heater core from the heater case
   
   

   

   

   Fig. View of the heater case assembly

   
   
   

   

   

   Fig. View of the heater core
   
   

To install:

1. Install or connect the following:
   
   
   Heater core to the heater case

   Heater core cover screws and tighten to 14 inch lbs. (1.5 Nm)

   Heater case assembly and the assembly-to-chassis screws, then, tighten the screws to 35 inch lbs. (4 Nm) and the nuts to 80 inch lbs. (9 Nm)

   Electrical connectors, as necessary

   Instrument panel carrier

   Mode control cable to the heater case assembly

   Temperature control cable to the heater case assembly

   Heater hoses to the heater core

   Negative battery cable.
   
   
2. Refill the engine cooling system.
3. Run the engine to normal operating temperatures; then, check the climate control operation and check for leaks.

Front

1. Drain the engine cooling system into a clean container for reuse.
2. Remove or disconnect the following:
   
   NOTE

   Removal of the heater assembly may require the help of an assistant.
   
   
   
   
   Negative battery cable

   Heater hoses from the heater core

   Instrument panel storage compartment

   Electrical connectors, as necessary, that may be in the way

   Center floor air distribution duct

   Hinge pillar trim kick panels

   Blower motor cover screws and the cover

   Blower motor screws and the blower motor

   Steering wheel and the steering column

   Instrument panel fasteners and pull the instrument panel back far enough to gain access to the heater assembly

   Screw located on the interior side near the evaporator pipe, if equipped, while holding the heater assembly against the firewall

   4 heater assembly-to-chassis screws and the 2 heater assembly-to-chassis nuts, working in the engine compartment
   
   
   
   
   7 heater cover-to-heater assembly screws and the cover

   Heater core from the heater assembly
   
   

   

   

   Fig. View of the HVAC assembly mounting

   
   
   

   

   

   Fig. Removing the heater core from the HVAC module
   
   

To install:

1. Install or connect the following:
   
   NOTE

   Installation of the heater assembly may require the help of an assistant.
   
   
   
   
   Heater core to the heater assembly

   Heater cover and the 7 heater cover-to-heater assembly screws
   
   
   
   
   4 heater assembly-to-chassis screws and the 2 heater assembly-to-chassis nuts. Torque the screws to 17 inch lbs. (1.9 Nm) and the nuts to 25 inch lbs. (2.8 Nm).

   Screw located on the interior side near the evaporator pipe, if equipped. Torque the screw to 97 inch lbs. (11 Nm).

   Instrument panel and the instrument panel fasteners

   Steering column and the steering wheel

   Blower motor and the blower motor screws

   Blower motor the cover and the cover screws

   Hinge pillar trim kick panels

   Center floor air distribution duct

   Electrical connectors that were disconnected

   Instrument panel storage compartment

   Heater hoses to the heater core

   Negative battery cable
   
   
2. Refill the engine cooling system.
3. Run the engine to normal operating temperatures; then, check the climate control operation and check for leaks.

1. Disconnect the negative battery cable.
2. Drain the engine cooling system into a clean container for reuse.
3. Disconnect the heater hoses from the heater core.
4. Remove the instrument panel storage compartment.
5. Disconnect the electrical connectors, as necessary, that may be in the way.
6. Remove the center floor air distribution duct.
7. Remove the hinge pillar trim kick panels.
8. Remove the blower motor cover screws and the cover.
9. Remove the blower motor screws and the blower motor.
10. Remove the steering wheel and the steering column (standard & tilt).
11. Remove the instrument panel fasteners and pull the instrument panel back far enough to gain access to the heater assembly.
12. While holding the heater assembly against the firewall, remove the screw located on the interior side near the evaporator pipe, if equipped.
13. In the engine compartment, remove the 4 heater assembly-to-chassis screws and the 2 heater assembly-to-chassis nuts.
    
    NOTE

    Removal of the heater assembly may require the help of an assistant.
    
    
14. Remove the 7 heater cover-to-heater assembly screws and the cover.
15. Remove the heater core from the heater assembly.
    
    
    

    

    Fig. View of the front heater assembly-Chevy/GMC C/K-Series, Blazer, Jimmy, Sierra, Suburban, Tahoe, Yukon

    
    
    
    

    

    Fig. Location of the front heater assembly-to-chassis fasteners-Chevy/GMC C/K-Series, Blazer, Jimmy, Sierra, Suburban, Tahoe, Yukon

To install:

1. Install the heater core to the heater assembly.
2. Install the heater cover and the 7 heater cover-to-heater assembly screws.
   
   NOTE

   Installation of the heater assembly may require the help of an assistant.
   
   
3. In the engine compartment, install the 4 heater assembly-to-chassis screws and the 2 heater assembly-to-chassis nuts. Torque the screws to 17 inch lbs. (1.9 Nm) and the nuts to 25 inch lbs. (2.8 Nm).
4. While holding the heater assembly against the firewall, install the screw located on the interior side near the evaporator pipe, if equipped. Torque the screw to 97 inch lbs. (11 Nm).
5. Install the instrument panel and the instrument panel fasteners.
6. Install the steering column (standard & tilt) and the steering wheel.
7. Install the blower motor and the blower motor screws.
8. Install the blower motor the cover and the cover screws.
9. Install the hinge pillar trim kick panels.
10. Install the center floor air distribution duct.
11. Connect the electrical connectors that were disconnected.
12. Install the instrument panel storage compartment.
13. Disconnect the heater hoses to the heater core.
14. Refill the engine cooling system.
15. Connect the negative battery cable.
16. Run the engine to normal operating temperatures; then, check the climate control operation and check for leaks.

Rear Heater Core

1. Disconnect the negative battery cable.
2. Drain the engine cooling system into a clean container for reuse.
3. Remove the rear quarter trim panel, as necessary.
4. Remove the right rear quarter trim panel.
5. Remove the right rear wheelhouse.
6. Disconnect the heater hoses from the rear auxiliary heater core.
7. Disconnect the electrical connectors, as necessary.
8. Remove the drain valve.
9. Remove the rear auxiliary heater assembly-to-chassis nuts and bolts.
10. Remove the rear auxiliary heater assembly.
11. If necessary, remove the blower motor from the heater assembly.
12. Remove the rear auxiliary heater assembly cover.
13. Remove the heater core from the rear auxiliary assembly.
    
    
    

    

    Fig. View of the rear auxiliary heater assembly-Chevy/GMC Suburban

To install:

1. Install the heater core to the rear auxiliary assembly.
2. Install the rear auxiliary heater assembly cover.
3. If removed, install the blower motor to the heater assembly.
4. Install the rear auxiliary heater assembly.
5. Install the rear auxiliary heater assembly-to-chassis nuts and bolts. Torque the bolts to 13 inch lbs. (1.5 Nm) and the nuts to 89 inch lbs. (10 Nm).
6. Install the drain valve.
7. Connect the electrical connectors, as necessary.
8. Connect the heater hoses from the rear auxiliary heater core.
9. Install the right rear wheelhouse.
10. Install the right rear quarter trim panel.
11. Install the rear quarter trim panel, as necessary.
12. Refill the engine cooling system.
13. Connect the negative battery cable.
14. Run the engine to normal operating temperatures; then, check the climate control operation and check for leaks.