Expansion Valves - Chevrolet 1977 light duty truck Service Manual

CORRECT
BLADE
ANGLE
LOWER
CASE HALF
Fig. lB-64--Blow er M otors (G Overhead System)
5. Remove the lower to upper blower-evaporator
case screws and lower
assemblies.
6. Remove the motor retaining strap and remove
the motor and wheels. Remove the wheels from the
motor shaft.
Installation
1. Place the blower wheels onto the motor shaft.
C A U TIO N : Be sure that the blower wheels are
installed as shown in Figure IB-64.
2. Install the blower m otor retaining strap and
foam strip.
3. Place the two
assemblies into the lower case. Aligtt the blower wheels
so that they do not contact the case.
4. Place the lower case and blower motor assemblies
in position in the vehicle and install the blower to upper
case screws.
N O T E: Rotate the blower wheels to make sure that
they do not rub on the case.
5. Install the center ground wires and connect the
blower lead wires.
6. Install the blower-evaporator shroud assembly
as described previously.
7. Connect the b attery ground cable and compres­
sor clutch connector.
E X P A N S IO N VALVES
This system incorporates
These valve do not use and external equalizer line (fig.
IB-65).
Removal (In n e r Valve)
the lower case and motor
blower m otor and wheel
two expansion valves.
V A L V E S
Fig. IB -65-E xpansion Valves (G Overhead System)
1. D isconnect the
compressor clutch connector.
2. Purge the system of refrigerant.
3. Remove the blo w er-ev apo rator
outlined previously.
W A R N IN G : Before rem oving the lower case
screws, support the case to prevent damage
to the case or m otor assemblies.
4. Disconnect the center ground wire and
blower motor lead wires. Remove the lower to upper case
screws and lower the lower case and blower motor
assemblies.
5. Disconnect the valve sensing bulb from the core
outlet line.
6. Disconnect the core inlet and outlet lines and
remove the valve assembly. C ap or plug the open
connections at once.
Installation (In n e r Valve)
1. Remove caps or plugs from system connections
and install the new valve assembly using new " O " rings
coated with clean refrigeration oil.
2. Install the sensing bulb, m aing sure that the
bulb makes good contact with the core outlet line.
3. Install the lower
assemblies.
4. Install the blower-evaporator shroud as outlined
previously.
5. Connect the battery ground cable and compres­
sor clutch connector.
6. Evacuate, charge and check the system.
Removal (O uter Valve)
1. D isconnect the
compressor clutch connector.
2. Purge the system of refrigerant.
V A L V E S E N S I N G
B U L B S
battery gro un d cable and
shroud
case and blower motor
battery g ro u n d cable and
as
the