GMC 4000 Series Service Manual page 99

Sec. 1
Page 92
AIR CONDITIONING
Figure 15— Hose and Clam p Properly Installed
from being thrown onto the clutch surfaces which
would cause slippage and eventual clutch failure.
1. Stamp refrigerant charge of the refrigerant
system on new com pressor in space on plate pro­
vided for this information.
NOTE: Follow procedure for replacing oil in
new com pressor explained previously under "Re­
moving Malfunctioning Compressor and Installing
New Compressor."
2. Install new com pressor to engine, leaving
com pressor fittings opening cover plate on the
com pressor.
3. Remove cover plate over com pressor open­
ings very slowly to bleed off pressure.
CAUTION: New com pressors are
charged with a mixture of nitrogen and
Refrigerant-12 and 11 fluid ozs. of
Frigidaire - 525 viscosity oil. If the
cover is removed too rapidly, the oil
will be blown out violently with the
sudden release of pressure.
4. Install coil and clutch parts if not already
installed.
5. Evacuate, charge and make a test of sy s­
tem as explained previously under "Performance
Testing."
SERVICING LEAKING SEALS
A N D HOSES
When refrigeration system components other
than the com pressor are replaced, the compressor
must also be removed and oil drained from the com­
pressor if oil was sprayed in copious amounts due
to severe leaks or broken lines. DO NOT add any
more oil than is necessary or maximum cooling will
be reduced. See "Checking Compressor Oil Level
and Adding Oil" previously.
1. Replace leaking seal, hose, or line. See
G M C S E R V I C E M A N U A L
figure 15 for proper positioning of hose and hose
clamp.
to 32 inch-pounds. After short period of time,
torque may drop off as low as 10 inch-pounds.
Final torque the clamp screw to 20 - 25 inch-
pounds.
test.
other than the com pressor are replaced, com pres­
sor must also be removed and oil drained from
com pressor if oil was sprayed in copious amounts.
See "Checking Compressor Oil Level and Adding
Oil" explained previously.
at condenser inlet.
openings.
outlet, then plug openings.
bolts and remove condenser.
using a new rubber O-ring seal well lubricated with
clean com pressor oil at line connection.
other than com pressor are replaced, the com pres­
sor must also be removed and oil drained from
com pressor if oil was sprayed in copious amounts
due to leaks or collision damage to receiver-de-
hydrator. See "Checking Compressor Oil Level
and Adding Oil" explained previously.
receiver at receiver-dehydrator assembly and plug
openings.
clamp screws and remove assembly.
by reversing the previous procedures, using new
rubber O-ring seal, well lubricated with clean com­
pressor oil, at line connection.
NOTE: The initial clamp screw torque is 25
2. Evacuate, charge and make performance
CONDENSER ASSEMBLY
REPLACEMENT
NOTE: When refrigeration system components
1. Depressurize the refrigeration system .
2. Remove radiator grille.
3. Remove com pressor discharge hose clamp
4. Remove hose from condenser inlet. Plug
5. Disconnect hex nut connection at condenser
6. Remove four condenser assembly retaining
7. Replace by reversing the above procedures,
8. Evacuate and charge system .
9. Make a performance test.
RECEIVER-DEHYDRATOR ASSEMBLY
REPLACEMENT
NOTE: When refrigeration system components
1. Depressurize the system .
2. Disconnect inlet and outlet connections of
3. Loosen the receiver-dehydrator assembly
4. Replace the receiver-dehydrator assembly
5. Evacuate complete system .
6. Charge complete system.
7. Make performance test.