Chevrolet 1977 light duty truck, Service Manual

Page: 83 / 861

2. Purge the system o f refrigerant.
3. Remove the grille assembly.
4. Remove the ra d ia to r grille center support.
5. Remove the left grille support to upper fender
support (2) screws.
6. Disconnect the condenser inlet an d outlet lines
and the outlet tube line at the right end o f the condenser.
C a p or plug all open connections at once.
7. Remove the condenser to ra d ia to r support
screws.
8. Bend the left grille support outboard to gain
clearance for condenser removal.
9. Remove the condenser assembly by pulling it
forw ard and then lowering it from the vehicle.
10. To install a new condenser, reverse Steps l -9
above. A dd one fluid ounce o f clean refrigeration oil to a
new condenser.
N O T E : Use new " O " rings, coated with clean
refrig eratio n oil, w hen connecting all re frig eran t
lines.
11. Evacuate, charge an d check the system.
A C C U M U L A T O R
Replacem ent (Fig. IB -3 5 )
1. Disconnect the battery ground cable and the
com pressor clutch connector.
2. Purge the system o f refrigerant.
W A R N IN G : Be sure system is completely
purged of refrig eran t before com pletely
d is c o n n e c tin g re frig e ra n t lines. Visually
check th e accu m u lato r fo r fro s t. T he
presence of fro s t indicates th a t the system is
not fully discharged. To com plete purging,
connect the vacuum line to th e vacuum
pump, turn on the vacuum pump and open
vacuum control valve. An alternate method
would be to place warm w ater soaked cloths
(n o t exceeding 51 C (125 F) around the
accum ulator to boil off any rem aining
refrigerant.
Fig. IB -3 5 -A c c u m u la to r In s ta lla tio n (C-K Models)
3. Disconnect the accumulator inlet and outlet
lines and cap or plug the open connections at once.
4. Remove the accumulator bracket screws and
remove the accum ulator from the vehicle.
5. D rain any excess refrig eran t oil from the
accumulator into a clean container. M easure and discard
the oil.
6. If a new accumulator is being installed, add one
ounce o f clean refrigeration oil to the new accumulator
PLUS an a m o u n t equal to that d rain ed in Step 5 above.
7. To install the new accumulator, reverse Steps 1-4
above. Connect all lines using new "O " rings, coated
with clean regrigeration oil.
C A U T IO N :
Do not uncap the new unit until
readv to fasten the inlet and outlet line to the
unit.
8. Evacuate charge and check the system.
BLOWER ASSEM BLY
Replacement
1. Disconnect the battery ground cable.
2. Disconnect the blower m otor lead and ground
wires.
3. Disconnect the blower m otor cooling tube.
4. Remove the blower to case attaching screws and
remove the blower assembly. Pry the blower flange away
from the case carefully if the sealer acts as an adhesive.
5. Remove the nut attaching the blower wheel to
the motor shaft and separate the assemblies.
6. To install, reverse Steps 1-5 above; replace
sealer as necessary.
EVA PO R A TO R CORE
Replacement (Fig. IB -3 6 )
1. Disconnect the battery ground cable.
2. Purge the system o f refrigerant.
3. Remove the nuts from the selector duct studs
projecting through the dash panel.
4. Remove the cover to dash and cover to case
screws and remove the evaporator case cover.
5. Disconnect the evaporator core inlet and outlet
lines and cap or plug all open connectins at once.
6. R em ove the th erm o static switch an d the
expansion tube assemblies.
7. Remove the e v ap o rato r core assembly.
8. To install, reverse Steps 1-7 above. A dd three
ounces o f clean refrigeration oil to a new evaporator
core.
C A U T IO N :
Be sure to install the thermostatic
switch capillary in the sam e position as when
removed. See Thermostatic switch replacement.