Auxiliary Heater Core Replacement Tahoe/Yukon
                    
Removal Procedure
- Remove the auxiliary HVAC module (4) from the vehicle. Refer to 
Auxiliary HVAC Module Replacement 
 
- Remove the air temperature actuator (1) from the auxiliary HVAC module.
 
- Remove the heater core cover (1) from the auxiliary HVAC module.
 
- Remove the heater core (1) from the auxiliary HVAC module.
 
Installation Procedure
- Install the heater core (1) to the auxiliary HVAC module.
 
- Install the heater core cover (1) to the auxiliary HVAC module.
 
- Install the air temperature actuator (1) to the auxiliary HVAC module.
 
- Install the auxiliary HVAC module assembly  (4) to the vehicle. Refer to 
Auxiliary HVAC Module Replacement 
 
                            Auxiliary Heater Core Replacement Suburban/Yukon XL
                    
Removal Procedure
- Remove the auxiliary HVAC module (3) from the vehicle. Refer to 
Auxiliary HVAC Module Replacement 
.
 
- Remove the air temperature actuator (1) from the auxiliary HVAC module.
 
- Remove the stud on the underside of the  auxiliary HVAC module between the heater core inlet and outlet pipes.
 
- Carefully separate the heater core pipe gasket from the module  case and remove the heater core pipe retainer.
 
- Remove the auxiliary HVAC module lower cover.
 
- Remove the heater core clamp.
 
- Remove the heater core from the auxiliary HVAC module.
 
Installation Procedure
- Install the heater core to the auxiliary HVAC module.
 
- Install the heater core clamp.
 
- Install the auxiliary HVAC module lower cover.
 
- Install the heater core pipe retainer and gasket.
 
- Install the stud between the heater core inlet and outlet on the  underside of the rear HVAC module.
 
- Install the air temperature actuator (1)  to the auxiliary HVAC module.
 
- Install the auxiliary HVAC module assembly  (3)  to the vehicle.