Primary Heater Core

Removal
1. Remove battery ground cable.
2. Remove coolant recovery tank.

Heater Hose Routing - 4.3, 5.0 And 5.7L Engines:

Heater Hose Routing - 6.2L Engines:

Heater Hose Routing - 7.4L Engine:

3. Remove heater core hoses.
- Place a clean pan under the vehicle to catch any coolant spillage.
- Plug the hoses.
- Allow coolant in the core to drain into the pan.





4. Remove heater distributor duct.
- Remove the screws that hold the distributor duct to the distributor case and the distributor duct to the engine cover.
5. Remove engine housing cover.
6. Disconnect instrument panel.
7. Lower the steering column.
- Raise and support the right side of the instrument panel.
8. Remove defroster duct to distributor case attaching screws.
9. Remove distributor to heater case screws.





10. Remove temperature door cable.
- Fold the cable back for access.

11. Remove heater case and core.
- Three nuts at the engine compartment side of the distributor case and one screw on the passenger side.
- Tilt the case assembly rearward at the top while lifting up until the core tubes clear the dash openings.
12. Remove core retaining straps.
13. Remove heater core.

Installation

1. Install heater core to the heater case.
- Apply a bead of permagum sealer between the core and the case.
2. Install core retaining straps.
3. Install heater case to the vehicle.
- Apply a bead of permagum sealer between the heater case and the opening in the vehicle.
- Tilt the case until the core tubes clear the cowl opening.
4. Install temperature cable to the heater case.
5. Install distributor duct (134) to the heater case (124).
6. Install defroster duct to the heater case.
7. Reconnect instrument panel.
8. Raise steering column.
9. Install engine housing cover
10. Install heater core hoses.
11. Install coolant recovery tank.
12. Install coolant to the radiator.
- Leak test the system.