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HEATER AND AIR CONDITIONING 1A-46
MAKE ANGULAR CUT
FOR HOSE REMOVAL
LOCATING
BEAD
SEALING
BEADS
LOCATING
BEAD
not to nick or score the sealing beads when
cutting off the hose. Cutting the hose lengthwise
may result in this problem.
Fig. 58—Hose Clamp Connections
NOTE:
Where steel to aluminum connections
are being made, use torque for aluminum tubing.
Hose Clamps (Fig. 58)
When hose clamp connections are encountered special
procedures are necessary for both installation and
removal.
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.
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.
(except Corvette) 30-38 lb. in. (Corvette). DO NOT
RETORQUE.
Removal
1. Carefully, with a sharp knife, make an angle cut in
the hose as shown in Figure 58. This should loosen
the hose so that it may be worked off the fitting.
2. Cut off slit end of hose when reinstalling. Reinstall
as described above.
CAUTION:
Use only approved refrigeration
hose. Never use heater hose. Use extreme care
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.
2. If the leak is still present, discharge the refrigerant
from the system as described under "Evacuating
and Charging Procedures."
3. Inspect the ''O" ring and the fitting and replace if
damaged in any way. Coat the "O". ring before re-
installed with refrigerati6n oil and install carefully.
4. Retorque the fitting, using a backing wrench, and
then add 1/2 to 1 lb. of R-12 to the system and
recheck for leaks.
CAUTION: Do not operate the system with this
small refrigerant charge.
5. Purge the system, thus removing the 1/2 to 1 lb.
installed in Step 4 above.
6. Evacuate and charge the system.
Leaks at Hose Clamp Connection
1. Check the tightness of the clamp itself and tighten
if necessary. Recheck for leak.
2. If leak has not been corrected discharge the system
and loosen clamp and remove hose from connection.
Inspect condition of hose and connector. Replace
scored or damaged parts.
3. Dip end of new hose in refrigerant oil and carefully
reinstall over connector. Never push end of hose
beyond the locating bead. Properly torque the clamp.
4. Recheck the system for leaks by installing 1/2 to 1
lb. of R-12 into the system. Do not run compressor.
5. Purge. the system, thus removing the 1/2 to 1 lb.
installed in Step 4 above.
6. Evacuate and charge the system.
Compressor Leaks
If leaks are located around the compressor shaft seal
or shell, replacement of necessary seals should be made
as outlined under "Compressor" in the Chassis Overhaul
Shop Manual.
REFRIGERANT HOSE FAILURE
After a leak or rupture has occurred in a refrigerant
hose, or if a fitting has loosened and caused a consider-
able loss of refrigerant and oil, the entire system should
be flushed and recharged after repairs have been made.
Ji the system has been open to atmosphere for any pro-
longed period of time the receiver-dehydrator should be
replaced.
PREPARING SYSTEM FOR REPLACEMENT
OF COMPONENT PARTS
Air conditioning, like many other things, is farily
simple to service once it is understood. However, there
CHEVROLET CHASSIS SERVICE MANUAL
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