Expansion Tube-All; Selector Duct And Heater Core; Control Assembly; Temperature Door Cable Adjustment - Chevrolet 1980 Light Duty Truck Service Manual

EXPANSIO N TUBE-CK, G
The expansion tube is located in the evaporator core
inlet line.
Replacement
1. Discharge system.
2. Disconnect the condenser to evaporator line at the
evaporator inlet. Cap the open line at once.
3. Using needle-nose pliers, remove the expansion tube
from the evaporator core inlet line.
4. Remove the expansion tube "O" ring from the core
inlet line.
5. To install, reverse Steps 1-4 above.
Install the expansion tube using a new "O" ring coated
with clean regrigeration oil, by inserting the short screen
end of the tube into the evaporator inlet line.
6. Evacuate, charge and check the system.

SELECTOR DUCT AND HEATER CORE

ASSEMBLY-CK
Replacement (Fig. 1B-30)
1. Disconnect the battery ground cable.
2. Drain the radiator and remove the heater hoses
from the core tubes. Plug the core tubes to prevent coolant
spillage during removal.
3. Remove the glove box and door as an assembly.
4. Remove the center duct to selector duct and
instrument panel screws and remove the center lower and
center upper ducts.
5. Disconnect the bowden cable at the temperature
door.
6. Remove the nuts from the three selector duct studs
projecting through the dash panel.
7. Remove the selector duct to dash panel screw
(inside vehicle).
8. Pull the selector duct assembly rearward until the
core tubes clear the dash panel. Lower the selector assembly
far enough to gain access to all vacuum and electrical
harnesses.
9. Disconnect the vacuum and electrical harness and
remove the selector duct assembly.
AIR C O N D ITIO N IN G
10. Remove the core mounting strap screws and remove
the core.
11. To install, reverse Steps 1-10 above.
12. Refill coolant system and connect the battery
ground strap. Check temperature door cable adjustment.
KICK PAD VALVE - CK SERIES
Replacement (Fig.
1B-31)
1. Disconnect the vacuum hose at the actuator.
2. Unhook the valve return spring at the actuator end.
3. Remove the actuator bracket mounting screws.
4. Remove the cam to actuator arm screw and separate
the actuator and bracket from the cam.
5. Remove the actuator to bracket nuts and separate
the actuator and bracket.
6. To install reverse Steps 1-5 above.
PLENUM VALVE - CK SERIES
Replacement (Fig.
1B-31)
1. Raise the hood.
2. Remove the cowl plastic grille.
3. Remove the three cowl to valve assembly screws and
remove the valve assembly from the vehicle.
4. Remove the actuator arm push nut.
5. Remove the actuator to valve nuts and separate the
valve and actuator.
6. To install, reverse Steps 1-5 above.
CONTROL ASSEM BLY - CK SERIES
Removal (Fig.
1B-32)
1. Disconnect the battery ground cable.
2. Remove the radio as outlined in Section 8 of this
manual.
3. Remove the instrument panel bezel.
4. Remove the control to instrument panel screws and
lower the control far enough to gain access to the control
assembly.
Be careful not to kink the bowden cable.
5. Disconnect the bowden cable, vacuum harness and
electrical harness at the control.
6. Remove the control.
7. If a new unit is being installed, transfer the master
blower switches to the new control.
8. To reinstall, reverse Steps 1-6 above. Check control
operation.
TEM PERATURE DOOR CABLE A D JU S TM E N T -
CK MODELS
1. Remove glove box and door assembly.
2. Loosen the cable attaching screw at the selector
duct assembly.
3. Make sure the cable is installed in the bracket on
the selector duct assembly.
4. Place temperature lever in full COLD position and
hold while tightening cable attaching screw.
MASTER S W ITC H A N D /O R BLOWER SW ITC H
- CK SERIES
The master switch is located on rear of the control
assembly.
IB -3 5
LIG H T T R U C K S ER V IC E MANUAL