Overhaul

DISASSEMBLY
1. Remove the heater-A/C unit housing from the vehicle and place it on a suitable work surface.

Heater-A/C Housing

REMOVAL
1. If the vehicle is equipped with the optional heater-A/C system, recover the refrigerant from the refrigerant system. Refer to Refrigerant Recovery for the proper procedures.
2. Drain the engine cooling system. Refer to Cooling System for the proper procedures. Service and Repair
3. Disconnect and isolate the battery negative cable.
4. Remove the instrument panel from the vehicle.Refer to Instrument Panel Systems for the proper procedures. Service and Repair
5. Disconnect the heater hoses from the heater core nipples at the dash panel. Refer to Heater Hose for the proper procedures.Service and Repair
6. Install plugs in the heater core nipples to prevent engine coolant spillage during heater-A/C unit housing removal.
7. If the vehicle is so equipped, relocate the vehicle speed control servo as necessary to access the right side of the dash panel. Refer to Vehicle Speed Control System for the proper procedures.Service and Repair
8. If the vehicle is equipped with the optional heater-A/C system.
a. Remove the two screws that secure the suction and liquid line assembly evaporator connector block to the evaporator.
b. Disconnect the suction and liquid line assembly evaporator connector block from the evaporator.
c. Remove the gasket from the suction and liquid line assembly evaporator connector block arid discard.
d. Install plugs in, or tape over the opened suction and liquid line assembly evaporator connector block ports and the evaporator inlet and outlet ports.
e. Remove the condensate drain tube from the heater-A/C unit housing drain. Refer to Condensate Drain Tube for the proper procedures.

Fig.67 Heater-A/C Vacuum Harness:

f. Disconnect the vacuum harness connector from the A/C vacuum check valve nipple near the power brake booster.
9. Remove the defroster duct from the heater-A/C unit housing. Refer to Ducts for the proper procedures.Service and Repair

Fig.68 Heater-A/C Unit Housing Remove/Intsall:

10. Remove the three nuts that secure the heater- A/C unit housing to the engine compartment side of the dash panel.
11. Remove the screw that secures the right end of the heater-A/C unit housing to the weld flange of the dash panel and cowl plenum panel in the passenger compartment.
12. Remove the nut that secures the heater-A/C unit housing to the cowl plenum bracket and stud on the passenger compartment side of the dash panel.
13. Remove the heater-A/C unit housing from the vehicle.

Fig.69 Heater-A/C Unit Housing Foam Seals:

2. Using a sharp razor or knife, carefully cut the foam seals on the air distribution outlets along the parting line between the upper and lower halves of the heater-A/C unit housing.

Fig.70 Heater-A/C Unit Housing Heater Core Flange:

3. Carefully remove the foam seal from the heater-A/C unit housing mounting flange where the nipples of the heater core exit the left end of the housing.

Fig.71 Heater-A/C Unit Housing Evaporator Flange:

4. If the vehicle is equipped with the optional A/C, using a sharp razor or knife, carefully cut the foam seal on the heater-A/C unit housing mounting flange along the parting line between the upper and lower halves of the housing where the evaporator tubes and connector block exit near the right end of the housing.
5. Remove all of the clips and screws that secure the upper an lower halves of the heater-A/C unit housing to each other.
6. Carefully separate the two halves of the heater-A/C unit housing. If there is any difficulty in separating the housing halves, check carefully for clips or screws that were overlooked in Step 5.

ASSEMBLY
1. If the vehicle is equipped with the optional A/C, before reassembly of the heater-A/C unit housing, be certain that the foam wrap is in place on the evaporator and that the evaporator tube rubber seal is properly captured in the channel at the evaporator mounting flange of the housing.
2. Assemble the upper half of the heater-A/C unit housing to the lower half. Be certain that the pivot shaft ends for the blend-air door and each mode door are properly positioned in their pivot holes in the housing.
3. Reinstall all of the clips and screws that secure the upper and lower halves of the heater-A/C unit housing to each other.Tighten the screws to 2.3 Nm (20 in. lbs.).
4. Reinstall the foam seal onto the heater-A/C unit housing mounting flange where the nipples of the heater core exit the left end of the housing.
5. Reinstall the heater-A/C unit housing into the vehicle. Refer to Heater-A/C Unit Housing for the proper procedures.