Heater Unit

REMOVAL

WARNING: DO NOT OPERATE THE DIESEL SUPPLEMENTAL CABIN HEATER IN AN ENCLOSED AREA SUCH AS A GARAGE THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS VENT THE CABIN HEATER EXHAUST WHEN OPERATING THE CABIN HEATER. ALLOW THE DIESEL SUPPLEMENTAL CABIN HEATER TO COOL BEFORE PERFORMING ANY SERVICE PROCEDURES TO THE CABIN HEATER. VERIFY THAT ALL DIESEL SUPPLEMENTAL CABIN HEATER FUEL LINES ARE SECURELY FASTENED TO THEIR RESPECTIVE COMPONENTS BEFORE PERFORMING ANY SERVICE PROCEDURES TO THE CABIN HEATER. FAILURE TO FOLLOW THESE WARNINGS MAY RESULT IN POSSIBLE PERSONAL INJURY OR DEATH.

1. Raise and support the vehicle. Take note of the location of the flexible section of the cabin heater exhaust tube.
2. Drain the engine cooling system.
3. Carefully open one hose to the underbody tube assembly and drain the remaining coolant. A salvage hose is a good idea to control the residual coolant, as flow will occur from both the cabin heater and the hose and tube assemblies.
4. Remove the second hose from the underbody hose and tube assembly.
5. Loosen the hose and tube assembly from the toe-board crossmember at two locations.
6. Disconnect the electrical connector from the body harness near the toe-board crossmember and rail.
7. Remove the wiring harness from the toe-board crossmember.
8. Open the fuel filler cap. Disconnect the rubber fuel hose between the body tube assembly and the fuel pump nipple at the body tube joint. A minimal amount of fuel may flow from the open port.

NOTE: Utilize an approved fuel storage container to catch any residual fuel.

9. Loosen the two fasteners at the rail. Take care to notice that the exhaust tube bracket tab is on top of the heater bracket and that there are two spacer washers installed between the rubber grommets.
10. Remove the flexible section of the cabin heater exhaust tube from the exhaust tube by loosening the clamp. Remove the hose from the exhaust tube. Removal of the rail tube assembly may aid in this service operation.
11. Remove seat hex nut at the heater mounting flange to crossmember.
12. Loosen the remaining fasteners which mount the exhaust tube assembly to the vehicle.
a. Install a suitable support device under the cabin heater and secure the cabin heater to the support.

13. Loosen the remaining three fasteners to the crossmembers.
14. Remove the loosened fasteners that support the cabin heater while supporting the weight of the heater.
15. Swing the cabin heater mounting bracket from between the exhaust bracket and rail mounting location. Drain any residual coolant from the cabin heater.
16. Remove the cabin heater from the vehicle.

INSTALLATION
1. Install the cabin heater mounting bracket between the exhaust bracket and the rail mounting location.
2. Support the cabin heater and install the fasteners that secure the cabin heater to the mounting bracket.
3. Install the three fasteners to the crossmembers. Tighten the M6 fasteners to 7 N.m (62 in. lbs.).
4. Position the two spacer washers between the body and the rubber grommets for the two mounting points on the rail.
5. Tighten the remaining M6 fasteners to 7 N.m (62 in. lbs.) and the M8 fasteners to 23 N.m (17 ft. lbs.) which mount the exhaust tube assembly to the vehicle.
6. Install the seat hex nut at the heater mounting flange to the crossmembers. Tighten the nut to 60 N.m (44 ft. lbs.)
7. Install the flexible section of the cabin heater exhaust tube to the exhaust tube. Tighten the M6 bolt of the clamp securely Install the hose to the exhaust tube.
8. Tighten the two M8 fasteners at the rail to 23 N.m (17 ft. lbs.). Taking care so that the exhaust tube bracket tab is on the top of the heater bracket.
9. Install the wiring harness.
10. Tighten the hose and tube assembly to the toe-board crossmember at two locations.
11. Install the second hose to the underbody hose and tube assembly.
12. Connect the rubber fuel hose between the body tube assembly and the fuel pump nipple at the body tube joint. Close the fuel fill cap.
13. Remove the cabin heater support device from under the vehicle.
14. Lower the vehicle.
15. Fill the engine cooling system.
16. Verify function of the heater unit.