Chevrolet 10 1971 Series, Руководство по обслуживанию шасси, Страница: 41 / 466

HEATER AND AIR CONDITIONING 1A-23
add the same amount of new refrigerant oil to the
replacement compressor.
b. If the quantity drained was less than 4 fluid oz.,
add 6 fluid oz. of new refrigeration oil to the
replacement compressor.
c. If a new service compressor is being installed,
drain all oil from it and replace only the amount
specified in Steps 3a and 3b above.
d. If a field repaired compressor is being installed,
add an additional 1 fluid oz. to the compressor.
4. In the event that it is not possible to idle the com­
pressor as outlined in Step 1 to effect oil return to
it, proceed as follows:
a. Remove the compressor, drain, measure and
discard the oil.
b. If the amount drained is more than 1-1/2 fluid
oz. and the system shows no signs of a major
leak, add the same amount to the replacement
compressor.
c. If the amount drained is less than 1-1/2 oz. and
COMPONENT REPLACEMENT
ALL SYSTEMS
PREPARING SYSTEM FOR
REPLACEMENT OF CO M PO NEN T PARTS
Air conditioning, like many other things, is fairly simple
to service once it is understood. However, there are
certain procedures, practices and precautions that should
be followed to prevent costly repairs, personal injury
or damage to equipment. For this reason it is strongly
recommended that the preceding information in this sec­
tion be studied thoroughly before attempting to service
the system.
Great emphasis must be placed upon keeping the sys­
tem clean. Use plugs or caps to close system com­
ponents and hoses when they are opened to the atmos­
phere. Keep your work area clean.
In removing and replacing any part which requires
unsealing the refrigerant circuit the following operations,
which are described in this section, must be performed
in the sequence shown.
1. Purge the system by releasing the refrigerant to the
atmosphere.
2. Remove and replace the defective part.
3. Evacuate and charge the system.
CAUTION:
Always wear protective goggles
when working on refrigeration systems. Goggles
J-5453 are included in the set of air conditioning
special tools.
Also, beware of the danger of
carbon monoxide fumes by avoiding running the
engine in closed or improperly ventilated
garages.
FOREIGN MATERIAL IN THE SYSTEM
Whenever foreign material is found in the system, it
must be removed before restoring the system to opera­
tion.
In the case of compressor mechanical failure, per­
form the following operations:
1. Remove the compressor.
2. Remove the receiver-dehydrator and discard the unit.
3. Flush the condenser to remove foreign material
which has been pumped into it.
the system appears to have lost an excessive
amount of oil, add 6 fluid oz. of clean refrigera­
tion oil to replacement compressor, 7 fluid oz. to
a repaired compressor.
If the oil contains chips or other foreign ma­
terial, replace the receiver-dehydrator and flush
or replace all component parts as necessary. Add
the full 11 fluid oz. of new refrigeration oil to the
replacement compressor.
5. Add additional oil in the following amounts for any
system components being replaced.
Evaporator Core.................................. 3 fluid oz.
Condenser............................................ 1 fluid oz.
Receiver-Dehydrator........................... 1 fluid oz.
NOTE:
When adding oil to the compressor, it
will be necessary to tilt the rear end of the
compressor up so that the oil will not run out
of the suction and discharge ports. Do not set
the compressor on the shaft end.
A N D M IN O R REPAIR
Disconnect the line from the receiver-dehydrator
at the inlet connection of the expansion valve. Inspect
the inlet screen for the presence of metal chips or
other foreign material.
If the screen is plugged,
replace it. Reconnect the line to the expansion
valve.
5. Install a new receiver-dehydrator.
6. Install the replacement compressor.
7. Add the necessary quantity of oil to the system (one
fluid ounce because of receiver-dehydrator replace­
ment plus the quantity needed for the replacement
compressor -
see "Checking Compressor Oil
Charge" under "Checking Oil."
8. Evacuate and charge the system.
9. Check system performance.
REFRIGERANT LINE CO NNECTIO NS
“O ” Rings
Always replace the "O" ring when a connection has
been broken. When replacing the "O" ring, first dip it
in clean refrigeration oil. Always use a backing wrench
on "O" ring fittings to prevent the pipe from twisting and
damaging the "O" ring. Do not overtighten. Correct
torque specifications are as follows:
Metal
Tube
O.D.
Thread and
Fitting
Size
Steel
Tubing
Torque*
Alum.
Tubing
Torque*
1/4
7/16 13
6
3/8
5/8 33
12
1/2 3/4
33 12
5/8 7/8
33 20
3/4 1-1/16
33 25
*Foot Pounds.
NOTE:
Where steel to aluminum connections
are being made, use torque for aluminum tubing.
Hose Clamps
When hose clamp connections are encounted, special
10-30 CHEVROLET TRUCK SERVICE MANUAL