Sight G Lass; Blower-Evaporator Assembly; Blower Assembly; Thermostatic And/Or Blower Switches - Chevrolet 1980 Light Duty Truck Service Manual

Use new "O" rings, coated with clean
NOTICE:
refrigeration oil, when connecting all refrigerant lines.
6. Evacuate, charge and check the system.
SIGHT GLASS REPLACEMENT
If damage to the sight glass should occur, a new sight
glass kit should be intalled. The kit contains the sight glass,
seal and retainer. (See Figure IB-68).
1. Purge system.
2. Remove the sight glass retainer nut using a
screwdriver and remove old glass and "O" ring seal.
3. Install the new glass and seal and retainer nut, being
careful not to turn the nut past the face of the housing. To
do so may damage the "O" ring seal.
4. Evacuate, charge and check the system.
BLOW ER-EVAPORATOR ASSEM BLY (Fig. IB -
69)
Removal
1. Disconnect battery ground cable.
2. Purge system of refrigerant.
3. Disconnect inlet and outlet refrigerant lines from
the back of unit. Cap or plug all open connections at once.
4. Disconnect drain tubes from evaporator case.
5. Disconnect electrical connector from compressor.
Remove the terminal (See Figure IB-70) and allow
connector to hang on ground wire.
6. Remove screws securing grommet retainer to dash
panel. Remove wire from grommet through slit.
7. Disconnect electrical lead at connector.
8. Remove unit mounting bolts. Remove unit from
vehicle, carefully pulling compressor electrical lead through
dash panel.
Once the unit has been removed from the vehicle,
continue with component replacement as follows:
AIR C O N D ITIO N IN G
BLOWER ASSEM BLY
Removal (Fig. 1B-71)
1. Remove the cover plate and separate the upper and
lower case halves. Remove blower motor mounting strap
screw and remove strap.
2. Remove blower assembly. Remove the wheels from
the motor shaft.
Installation
1. Install the blower wheels on the motor so that the
lower blades curve toward the dash panel side of the unit
when the motor is placed in the case as illustrated in Figure
IB-85.
2. Place the motor in the bracket with the electrical
connector side of the motor to the right side of the bracket.
Attach the mounting strap. Align blower wheels so that they
do not contact case.
3. Assemble the case halves and attach the cover plate.
4. Reverse Steps 1-8 on the "Blower-Evaporator
Assembly" removal procedure.
5. Evacuate, charge and check the system.
EXPANSIO N VALVE, EVAPORATOR A N D /O R
EVAPORATOR CASE
Removal (Fig. 1B-72)
1. Remove the cover plate and separate upper and
lower case halves.
2. Remove inlet and outlet lines from the expansion
valve. Remove sensing bulb from the evaporator outlet
manifold. Remove expansion valve. Cap or plug open
connections at once.
3. Remove evaporator core retaining screws and
remove core.
4. Remove blower motor and harness assembly from
case.
Installation
1. Reverse applicable steps in the removal procedure.
Use new "O" rings coated with clean
NOTICE:
refrigeration oil when connecting lines. Add 3 oz. of
new refrigeration oil to a new core.
2. Reverse steps 1-8 of the "Blower Evaporator
Assembly" removal procedure.
3. Evacuate, charge and check the system.
TH E R M O S TA TIC A N D /O R BLOWER
SW ITCHES
Replacement
1. Remove the cover plate assembly from the
evaporator case.
2. Remove two screws securing either switch to the
cover plate and remove appropriate switch (fig. IB-73).
3. Install replacement switch, reinstall cover plate and
reverse steps 1-8 of the "Blower-EVaporator Assembly"
removal precedure.
When installing thermostatic switch, be sure to
position sensing capillary as when unit was removed.
1 B-53
LIG H T T R U C K S ER V IC E MANUAL