Chevrolet Light Duty Truck 1973 Service Manual page 44

1A-18 HEATER A ND AIR C O N D IT IO N IN G
General Description.........................................................1A-19
Four-Season System (C-K M odels)......................... .1A-19
Floor Mounted System (G Models)........................ .1A-19
Overhead Systems (C-K-G Models)........................ .1A-19
Motor Home Chassis System..................................... .1A-19
Theory of Operation........................................................1A-20
H eat.................................................................................... .1A-20
Refrigerants.......................................................................1A-23
Air Conditioning.............................................................1A-26
Basic Air Conditioner....................................................1A-26
Main Units of the System......................................... .1A-28
Chemical Ingredients of an Air Conditioning
System...............................................................................1A-35
Primary Causes of System Failures........................ .1A-36
System Controls.............................................................. .1A-38
General Inform ation........................................................1A-39
Precautions in Handling R efrigerant-12.................1A-39
Precautions in Handling Refrigerant Lines...........1A-40
M aintaining Chemical Stability in the
Refrigeration System ............................................... .1A-40
J-8393 Charging Station................................................1A-41
Gauge S et..........................................................................1A-41
Vacuum Pump................................................................. .1A-42
Leak Testing the System ............................................ .1A-42
Availability of Refrigerant-12....................................1A-43
Compressor O il............................................................... .1A-44
Compressor Serial N um ber........................................ .1A-44
Inspection and Periodic Service...................................1A-44
Pre-Delivery Inspection..................................................1A-44
6000 Mile Inspection......................................................1A-44
Periodic Service.............................................................. .1A-44
Evacuating and Charging Procedures....................... .1A-44
Air Conditioning System C apacity......................... .1A-44
Installing Charging Station........................................ .1A-44
Purging the System........................................................1A-45
Evacuating and Charging the System.....................1A-45
Performance Test........................................................... .1A-47
Performance D ata.......................................................... .1A-48
Checking O il.....................................................................1A-49
Refrigerant Quick-Check Procedure....................... ..1A-50
Maintenance and Adjustm ents.....................................1A-51
Thermostatic Switch.......................................................1A-51
Expansion Valve............................................................. .1A-52
Engine Idle Com pensator.............................................1A-53
General Repair Procedures.......................................... .1A-53
Preparing System for Replacement of Component
Parts.................................................................................. .1A-53
Foreign Material in the System ................................1A-53
Refrigerant Line Connections....................................1A-53
Repair of Refrigerant Leaks..................................... .1A-54
Refrigerant Hose Failure..............................................1A-54
Com pressor........................................................................1A-55
Compressor F ailure........................................................1A-57
False Compressor Seizure........................................... .1A-57
Collision Procedure-All Vehicles................................1A-57
AIR CONDITIONING
INDEX
Component Part Replacement—Four-Season
System.............................................................................. 1A-58
Condenser.......................................................................... 1A-58
Accumulator...................................................................... 1A-58
Blower Assembly............................................................ 1A-59
Evaporator Core.............................................................. 1A-59
Expansion Tube............................................................... 1A-59
Selector Duct and Heater C o re................................ 1A-60
Kick Panel Air Valve................................................... 1A-60
Plenum Air Valve.......................................................... 1A-60
Control Assembly........................................................... 1A-60
Master Switch and/or Blower Switch..................... 1A-61
Vacuum Tank................................................................... 1A-61
Blower Resistor U nit..................................................... 1A-61
Blower Motor Relay...................................................... 1A-62
Thermostatic Switch...................................................... 1A-62
Discharge Pressure Switch........................................... 1A-62
Fuse..................................................................................... 1A-63
Component Part Replacement - Overhead System
(C-K Models)................................................................. 1A-64
Rear D uct......................................................................... 1A-64
Blower Motor Resistor.................................................. 1A-64
Blower Motor Assembly............................................... 1A-65
Expansion Valve.............................................................. 1A-66
Evaporator Core.............................................................. 1A-66
Blower Motor Switch.................................................... 1A-67
Fuse..................................................................................... 1A-67
Component Part Replacement - Floor Mounted
System (G Models)...................................................... 1A-67
Condenser.......................................................................... 1A-67
Receiver-Dehydrator...................................................... 1A-68
Sight Glass Replacem ent............................................. 1A-68
Blower-Evaporator Cover............................................. 1A-68
Blower-Evaporator Assembly...................................... 1A-68
Expansion Valve and/or Evaporator C o re........... 1A-68
Blower M otor................................................................... 1A-70
Electrical Components................................................... 1A-70
Low Refrigerant Charge Protection System........ 1A-70
Super Heat Switch....................................................... 1A-71
Thermal Fuse................................................................. 1A-71
Circuit Breaker................................................................ 1A-72
Component Part Replacement - Overhead System
(G M odels)..................................................................... 1A-72
Blower-Evaporator Shroud........................................... 1A-73
Blower Motor Assemblies............................................ 1A-73
Expansion Valves............................................................ 1A-73
Evaporator Core.............................................................. 1A-75
Resistor............................................................................... 1A-75
Blower Switch................................................................... 1A-75
Rear Blower R elay........................................................ 1A-75
Tie R elay.......................................................................... 1A-75
Component Part Replacement - Motor Home
Chassis U nits................................................................. 1A-75
Condenser.......................................................................... 1A-75
LIGHT DUTY TRUCK SERVICE MANUAL