Chevrolet 30 Series 1967 Service Manual page 50

HEATER AND AIR CONDITIONING 1A-22
add an additional
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 fluid oz.
and the system appears to have lost an excessive
amount of oil add
6
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 fluid oz. of new refrigeration oil to the
1 1
replacement compressor.
5. Add additional oil in the following amounts for any
system components being replaced.
E v a p o ra to r................................................
Condenser ................................................
Receiver-Dehydrator ............................
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.
the compressor on the shaft end.
COMPONENT REPLACEMENT AND MINOR REPAIRS
REFRIGERANT LINE CONNECTIONS
" O" Rings
Always replace the "0 '' ring when a connection has
been broken. When replacing the "O" ring, first dip it
in refrigeration oil. Always use a backing wrench on
" " ring fittings to prevent the pipe from twisting and
0
damaging the "O" ring.
torque specifications are as follows:
Metal Thread and
Tube Fitting
O.D. Size
1/4 7/16
3/8
5/8
3/4
1 / 2
5/8 7/8
3/4
1-1/16
* Pound Feet
NOTE: Where steel to aluminum connections
are being made, use torque for aluminum tubing.
Hose Clamps
When hose clamp connections are encountered special
procedures are necessary for both installation and r e ­
moval.
Installation
1. Coat tube and hose with refrigeration oil.
2. Carefully insert hose over the three beads on the
fitting and down as far as the fourth, or locating
bead. Hose must butt against this fourth bead.
fluid oz. to the compressor.
1
fluid oz. of clean refrigeration
3 fluid oz.
1 fluid oz.
1 fluid oz.
Do not set
Do not overtighten. Correct
Steel Alum.
Tubing Tubing
Torque*
Torque*
13
6
33
1 2
33
1 2
33
2 0
33 25
ADDING OIL TO THE SYSTEM
The system should be completely assembled and un­
charged before adding oil. Use only uncontaminated
refrigerant oil and add as follows:
1. Connect the low pressure gauge line to the low
pressure gauge fitting on the P.O.A. valve.
2. Connect the high pressure line from the charging
station gauge set to the compressor muffler.
3. Disconnect the high pressure line from the gauge
set, make certain that the line is clean, and place
the end in a graduated oil container.
4. Pour enough refrigerant oil in the container so that
the required volume may be drawn into the system
by the high pressure hose.
5. Close the high pressure valve at the gauge set, and
open the low pressure valve.
. Operate the vacuum pump to drop the pressure within
6
the system and cause atmospheric pressure to force
oil through the high pressure line into the system.
When the oil level has dropped the required volume,
pull the line out of the oil container and continue
vacuum pump operation to force the oil contained in
the line into the system.
7. Shut off the vacuum pump and connect the high pres­
sure line to the gauge set. Open the high pressure
valve and evacuate the system through the high and
low pressure side of the system.
charging operation as outlined in Step 10 under
"Evacuating and Charging System".
CAUTION:
Use no sealer of any kind.
3. Install clamps on hose, hooking the locating arms
over the cut end of the hose.
4. Tighten the hose clamp screw to 35-42 lb. in.
torque. DO NOT RETORQUE. The clamp screw
torque will normally decrease as the hose conforms
to the force of the clamp. The screw should be
retorqued only if its torque falls below
In this case, retorque to 20-25 lb. in.
tightening may damage the hose.
Removal
1. Carefully, with a sharp knife, make an angle cut in
the hose as shown in Figure 32. This should loosen
the hose so that it may be worked off the fitting.
2. Cut off slit end of hose when reinstalling.
as described above.
CAUTION:
Use only approved refrigeration
hose. Never use heater hose. Use extreme
care not to nick or score the sealing beads when
cutting off the hose.
may result in this problem"!
REPAIR OF REFRIGERANT LEAKS
Any refrigerant leaks found in the system should be
repaired in the manner given below:
Leaks at " O" Ring Connection
1. Check the torque on the fitting and, if too loose,
tighten to the proper torque. Always use a backing
wrench to prevent twisting and damage to the "O"
ring. Do not overtighten. Again leak test the joint.
Complete the
lb. in.
1 0
Further
Reinstall
Cutting the hose lengthwise
CHEVROLET TRUCK SERVICE MANUAL