Chevrolet 1980 Light Duty Truck Service Manual page 73

M ETAL TUBE STEEL
TH R E A D AN D
OUTSIDE TUBING
F IT T IN G SIZE
DIAM ETER TORQUE
J f
f
1/4 7/16 10-15
3/8 5/8 30-35
1/2 3/4 30-35
5/8 7/8
30-35
3/4
1 1/16 30-35
All sub-assemblies are dehydrated and sealed prior to
shipping. They are to remain sealed until just prior to
making connections. All sub-assemblies should be at room
temperature before uncapping (this prevents condensation
of moisture from the air that enters the system). If, for any
reason, caps are removed but the connections are not made,
parts should be resealed as soon as possible.
All precautions should be taken to prevent damage to
fittings or connections. Any fittings getting grease or dirt
on them should be wiped clean with a cloth dampened with
Stoddard solvent, kerosene (or equivalent) may be used.
Make sure fittings are dry prior to re-assembly. If dirt,
grease or moisture get inside pipes and cannot be removed,
the pipe should be replaced.
Sealing caps should be removed from sub-assemblies
just prior to making connections for final assembly. Use a
small amount of clean 525 viscosity refrigerant oil on all
tube and hose joints. Always use new O-rings dipped in the
clean refrigerant oil when assembling joints. The oil will aid
in assembly and help provide a leak-proof joint. When
tightening joints, use a second wrench to hold stationary
part of connection so that a solid feel can be attained. This
will indicate proper assembly.
Tighten all tubing connections as shown in
NOTICE:
torque chart (Chart IB-9). Insufficient or excessive
torque when tightening can result in loose joints or
deformed joint parts. Either condition can result in
refrigerant leakage.
C.C.O.T. REFRIGERANT OIL DISTRIBUTIO N
A-6 COMPRESSOR SYSTEM - requires 300 ml (10
fluid ounces) of 525 viscosity oil.
R-4 COMPRESSOR SYSTEM - requires 180 ml (6
fluid ounces) of 525 viscosity oil.
New oil quantities must be added to the system during
Service component replacement and conditions stated as
follows:
A. When there are no signs of excessive oil leakage, for
the -
A L U M IN U M OR
COPPER NO M IN A L
TU BING TORQUE
TORQUE WRENCH SPAN
T N -n
LB, FT, N m
14-20 5-7 7-9 5/8
41-48 11-13 15-18 3/4
41-48 15-20 20-27 7/8
41-48 21-27 29-37 1 1/16
41-48 28-33 38-45 1 1/4
AIR C O N D ITIO N IN G
• Compressor - Remove, drain oil, measure, replace
same amount of new oil plus 30 ml (1 oz.).
• Evaporator - Add 90 ml (3 fluid ounces).
• Condenser - Add 30 ml (1 fluid ounce).
• Accumulator - Remove, drain oil, measure, replace
same amount of new oil
plus
for that retained by the original accumulator dessicant.
B. With signs of excessive oil leakage, for -
Compressor Systems
A-6
Remove Compressor AND Accumulator. Drain,
measure and record TOTAL oil from both components.
Discard old oil.
If less than 180 ml (6 ounces), add 6 ounces of new oil
to system.
If more than 180 ml (6 ounces), add same amount of
new oil as drained.
If a new Accumulator must be added to A-6 system,
add 1 additional ounce of oil to compensate for that held/
absorbed by the original accumulator dessicant.
Compressor Systems
R-4
Remove only the Accumulator. Drain, measure and
record quantity of oil in Accumulator. (It is not necessary
to remove and drain the R-4 Compressor because the R-4
Compressor only retains a minimum quantity of oil-it
doesn't have an oil sump area.)
If less than 90 ml (3 ounces), add 90 ml (3 ounces) of
new oil to system.
If more than 90 ml (3 ounces), add same amount of new
oil as drained.
If a new Accumulator must be added to R-4 system,
add 30 ml (1 ounce) of oil to compensate for that held/
absorbed by the original Accumulator dessicant.
1. If there are no signs of excessive oil leakage, add the
following amount of oil depending on component replaced:
For A-6 & R-4 Compressor Systems - Evaporator - (3
fluid ounces).
For A-6 & R-4 Compressor Systems - Condenser - (1
fluid ounce).
For R-4 Compressor System only - Accumulator
(Drain oil, measure, replace same amount plus 1 oz.).
For A-6 Compressor System only - Accumulator (see
Item 2 below).
2. However, on an A-6 compressor system:
• If either the accumulator or the compressor is to be
replaced...
• Or if there are signs of abundant oil leakage...
THEN BOTH
COMPRESSOR must be removed - oil drained - and
measured to determine correct quantity of oil replacement
for the system. If the amount of oil recovered is 4 oz. or
more, replace with a like amount of new oil. If less than 4
oz. are recovered, add 6 oz. of new oil.
A good A-6 system will have 6 ounces of oil found in
the accumulator and/or compressor. Neither necessarily
has 3 ounces - could be more or less. This is why BOTH
have to be measured.
• IN ADDITION to these measure amounts, one (1)
additional fluid ounce MUST be added to replace that
amount captured in the oil desiccant of the replaced
accumulator assembly.
1B-27
30 ml oz.) to compensate
(1
ACCUMULATOR AND
LIG H T T R U C K SER V IC E M ANUAL