Chevrolet 70 1969 Series, Руководство по ремонту

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C A B A N D BO D Y M O U N T IN G S 1-66
white felt bag that is not attached to anything but
merely rests on the baffle in the lower portion of
the receiver. As the refrigerant flows through an
opening in the lower portion of the receiver, it is
also filtered through a 100 mesh screen attached
to a baffle at the bottom of the receiver.
The de sic cant in this assembly is to absorb
any moisture that might be present in the system
after assembly. The screens trap any foreign m a­
terial which may enter the system during assembly.
These features of the assembly prevent obstruc­
tion to the valves or damage to the compressor.
N O T E : Markings on top of the receiver show
the proper inlet and outlet fitting connections.
ON-VEHICLE SERVICE
Contents of this Sub-Section are as follows:
Subject Page No.
Periodic Service ......................... ............................... ......................... 1-66
Precautionary Service Measures ................................................ ... 1-66
Performance Testing ................................................... ... 1-67
Depressurizing the System ...................................................... ... 1-70
Evacuating the System ......................................................................... 1-70
Charging the S y s t e m ............. ............................... ... 1-72
Adding Refrigerant (Small Amount) ................................................... 1-74
Checking Compressor Oil Level and Adding Oil ................................ 1-75
Checking for L e a k s ...................... ......................................................... 1-76
Replacing Compressor ................ ........................................................ 1-77
Servicing Seals and Hoses ................................................................... 1-79
Condenser Assembly R e p la c e m e n t............. ... 1-79
Receiver-Dehydrator Assembly Replacement ................... ... 1-79
Expansion Valve Replacement . .......................................................... 1-80
Suction Throttling Valve Replacement . . . . . . . . . . . . . . . . 1-80
Evaporator and Heater Core, Assembly Replacement . .................... 1-80
Collision Service ................... ............................... ... 1-80
Blower Motor Replacement ............................. ..................................... 1-81
PERIODIC SERVICE
(60 Days or 6000 Miles whichever occurs first)
1. Check front of condenser for an accumula­
tion of dirt, such as leaves, bugs, dirt, etc. Also
check to see that the space between the condenser
and radiador is also free of this material.
2. Inspect compressor drive belt. Check and
adjust tension to 100 to 105 lbs. on belt tension
gauge. Adjust new belt tension to 130 to 140 lbs.
3. Operate system and check for correct oper­
ation in all control positions.
4. Check for refrigerant leaks and observe
refrigerant passing through the sight glass with
system operating to see if there is any evidence of
bubbles (above 70°F. ambient).
PRECAUTIONARY SERVICE
MEASURES
Before any service is attempted which requires
the opening of refrigeration pipes or units, the
person doing the work should be thoroughly familiar
with "General Information" on refrigeration serv­
ice.
The major reasons behind these measures are
for safety and to prevent dirt and moisture from
getting into the system. Dirt contaminant is apt to
cause leaky valves or wear in the compressor, and
moisture will freeze into ice at the expansion valve
and freeze the valve stem.
PRE- ASSEM BLY
1. All sub-assemblies are shipped, sealed and
dehydrated. They are to remain sealed until just
prior to making connections.
2. All sub-assemblies should be at room
temperature before uncapping. (This prevents con­
densation of moisture from the air that enters into
the system.)
3. If, for any reason the caps are removed,
but the connections are not made, then the tubes
and other parts should not remain unsealed for
more than 15 minutes. Reseal connections if period
is to be longer. This applies particularly to par­
tially built-up systems that will be left overnight.
4. Compressors are shipped with 10 - 11 oz.
of Frigidaire-525 Viscosity Oil and charged with
a mixture of Refrigerant-12 and dry nitrogen to
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L