Chevrolet 1977 light duty truck, Service Manual

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Fig. lB -4 8 -B lo w e r-E va p o rato r (C-K Overhead System)
Fig. lB-49--Blow er M otor (C-K Overhead System)
7. Connect the battery ground cable.
E X P A N S IO N VALVE
This sytem incorporates an d expansion valve which
does not utilize and external equalizer line (fig. IB-50).
Removal
1. Disconnect battery ground cable.
2. Purge the system o f refrigerant.
3. Remove the rear duct as outlined previously.
4. Disconnect the blower m otor lead and ground
wires.
5. Remove the lower to upper blower-evaporator
case screws an d lower the lower case and motor
assembly.
C A U T IO N :
Before rem oving the case screws,
support the lower case a n d motor assemblies.
6. Remove the expansion valve sensing bulb
clamps.
7. Disconnect the valve inlet and outlet lines and
remove the expansion valve assembly. Cap or plug the
open connections at once.
Installation
1. Remove caps or plugs fro m system connections
and install the new valve assembly using new " O " rings
coated with clean refrigeration oil.
2. Install the sensing bulb, m aking sure that the
bulb makes good contact with the core outlet line.
3. Install the lower case and blower motor
assemblies. Connect the blower m otor lead and ground
wires.
4. Install the rear duct as outlined previously.
5. Connect the battery ground cable.
6. Evacuate, charge and check the system.
EVA PO R A TO R CORE(Fig. IB -5 0 )
Removal
1. Disconnect the battery ground cable.
2. Purge the system or refrigerant.
3. Remove the rear duct as outlined previously.
4. Disconnect the blower m otor lead and ground
wire connections.
5. Disconnect the refrig eran t lines at the rear o f
the blow er-evaporator assembly. C ap or plug the open
connections at once.
6. Remove the blower-evaporator support to roof
rail screws, lower the blower-evaporator assembly and
place it on a work bench upside down.
7. Remove the lower to upper case screws and
remove the lower case assembly. Remove the support to
upper case screws and remove the upper case from the
evap o rato r core.
8. Remove the expansion valve inlet and outlet
lines and cap or plug the open connections at once.
Remove the expansion valve capillary bulb from the
evaporator outlet line and remove the valve.
9. Remove the plastic pins hold ing the screen to
the core and remove the screen.
Installation
M O T O R C L A M P
F O A M STRIP
L O W E R
E V A P O R A T O R C A S c
B L A D E
A N G L E
E V A P O R A T O R
S C R E E N
B L O W E R - E V A P O R A T O R
UPPER C A S E
E X P A N S I O N
V A L V E
E V A P O R A T O R
C O R E S E N S IN G BU LB