Chevrolet 1977 light duty truck, Service Manual

Page: 82 / 861

com pressor brackets to the m ounting bracket. Remove
the compressor.
6. Before beg in n in g any compressor disassembly,
d ra in and m easure oil in the compressor. Check for
evidence o f c o n ta m in a tio n to d eterm ine if re m a in d e r o f
system requires servicing. C om pressor servicing i n f o r m a ­
tion is located in the Overhaul M anual.
Installation
1. If oil previously d rain ed from the compressor
upon removal shows no evidence o f contam ination,
replace a like a m o u n t o f fresh refrigeration oil into the
com pressor before reinstallation. If it was necessary to
service the entire system because o f excessive c o n ta m in a ­
tion in the oil removed, install a full charge o f fresh
re frig e ratio n oil into the compressor.
2. Position compressor on the m ounting bracket
a n d install all nuts, bolts and lock washers.
3. Install the connector assembly to the compressor
r e a r head, using new " O " rings coated with clean
r e frig e ratio n oil.
4. Connect the electrical lead to the coil and install
and adjust compressor belt.
5. Evacuate, charge and check the system.
G and M o to r H om e Chassis M odels
R em oval (Fig. IB -3 3 )
1. Disconnect battery g round cable.
2. Disconnect compressor clutch connector.
3. Purge the system o f refrigerant.
4. Release the belt tension at the idler pulley and
rem ove the bit from the compressor pulley. On some
vehicles it m ay be necessry to remove the crankshaft
pulley in o rder to remove the belt.
5. G M o d els-R em o v e the two bolts and two
clamps that hold the engine cover and remove the cover.
6. Remove the air cle aner to aid access to the
compressor.
7. Remove fitting and muffler assembly and cap or
plug all open connections.
8. Remove the nuts and bolts attaching the
com pressor to the bracket.
9. Remove the engine oil tube support bracket bolt
and nut from the compressor, also compressor clutch
g round lead.
Before beginning any compressor disassembly,
d ra in and m easure oil in the compressor. Check for
evidence o f con taim in atio n to d eterm ine if re m a in d e r o f
system requires servicing. C om pressor Servicing i n fo r­
m ation is located in the O verhaul Manual.
Installation
l. If the oil drained from the compressor showed
no evidence o f co n tam in atio n replace a like am ount o f
fresh re frig e ratio n oil into the compressor before
reinstallation. If it was necessary to service the entire
system because o f excessive co n tam in atio n in the oil
rem oved, install a full charge o f fresh refrigeration oil in
the compressor. (See C hecking C om pressor Oil C harge
in the D iagnosis Section o f this Service M anual.)
2. Position compressor on the m ounting bracket
and install all nuts, bolts, lock washers, and g round wire.
3. Install the connector assembly to the compressor
rear head, using new " O " ring coated with clean
refrigeration oil.
4. Connect the electrical lead to the coil and install
and adjust compressor belt, using idler pulley. See
"C om pressor Belt Tension A djustm ent."
5. Evacuate, charge and check the system.
6. Replace air cleaner. On G models, replace the
engine cover.
7. Connect the battery ground cable.
Com pressor B elt Tension A djustm ent
Adjust the compressor belt to the specifications
shown in the T u n e -U p ch art in the Engine section o f the
Service Manual.
N O TE: On some G and M otor Home Chassis
models it may be necessary to increase idler pulley
slack adjustment. This may be accomplished by ( l)
Remove and discard the idler adjustm ent bolt. (2)
Remove the idler backing plate and elongate all 3
adjusting slots 1/2 inch inboard or outboard as
required. (3) Reinstall the idler assembly and
adjust belt tension using a lever (screwdriver, etc.)
to move the pulley outboard until proper belt
tension is reached. If the belt is being replaced it
may be necessary to remove and replace the
throttle cable during the belt replacement. If so
check throttle cable adjustm ent upon completion. It
may also be necessary to remove the crankshaft
pulley to install a new compressor belt.
FOUR-SEASON SYSTEM-C-K
MODELS
CO NDENSER
Replacement (Fig. IB -3 4 )
l. Disconnect battery ground cable.