backed off, immediately point the end of hose toward
floor, as possibly trapped refrigerant in the hose will
be released.(e) Install service port cap.
DISCHARGE (HIGH PRESSURE) GAUGE CONNECTION (1) Remove the service port cap from the 1/4 in.
service port. (2) Check all valves on the equipment being used to
verify they are closed. (3) Inspect the hose gasket in the service port con-
nector at the end of the (RED) hose. If the gasket is
flawed, replace it. (4) Use a suitable (3/8 in. male to 1/4 in. female)
adapter (Fig. 5), threaded securely into the end of the
(RED) hose connector.
(5) Thread the 1/4 in. hose adapter connector onto
the service port. Quickly secure adapter connector to
service port to avoid loosing refrigerant. To disconnect the discharge gauge (RED) hose:(a) Wrap the end of hose with a shop towel.
(b) Loosen the hose connector.
(c) Push and hold the end of hose toward the
service port to keep the gasket in contact with service
port. (d) Quickly rotate the connector counterclockwise.
When the hose connector is completely backed off,
immediately point the end of hose toward floor, as
possibly trapped refrigerant in the hose will be
released. (e) Install service port cap.
EVACUATION/RECOVERY/RECYCLING/CHARGING LINE CON-
NECTION
The center manifold (YELLOW) or (WHITE) hose is
used to recycle, recover, evacuate, and charge the
refrigerant system. When the discharge or suction
valves on the manifold gauge set are opened, the
refrigerant in the system will escape through this hose. This hose should be attached to a R-12
Recovery/Recycling device. Refer to the
Recovery/Recycling devices operators manual
for procedures. For disconnection of this hose, refer to Disconnect-
ing the Discharge Gauge (RED) hose in the preced-
ing paragraphs.
TESTING FOR REFRIGERANT LEAKS
If the A/C system is not cooling properly, deter-
mine if the refrigerant system is fully charged with
R-12. Follow the procedures in the Performance Test
Procedures section of this Group. If the refrigerant
system is empty or low in refrigerant charge, a leak
at any line fitting or component seal is likely. To de-
tect a leak in the refrigerant system, perform one of
the following procedures as indicated by the symp-
toms.
EMPTY REFRIGERANT SYSTEM LEAK TEST
CAUTION: Review Safety Precautions and Warnings
in General Information section of this Group.
(1) Evacuate the refrigerant system to the lowest
degree of vacuum possible. (2) Prepare a 10 oz. refrigerant (R-12) charge to be
injected into the system. Refer to Charging Refriger-
ant System for instructions. (3) Connect and dispense 10 ozs. of refrigerant into
the evacuated refrigerant system. (4) Proceed to step two of Low Refrigerant Level
Leak Test.
LOW REFRIGERANT LEVEL LEAK TEST
Caution: Review Safety Precautions and Warnings
in the General Information section of this group.
(1) Using the refrigerant level sight glass, deter-
mine if there is any (R-12) refrigerant in the system. (2) Position the vehicle in a wind free work area.
This will aid in detecting small leaks. (3) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run for five minutes. (4) With the engine not running, use an Electronic
Leak Detector (or equivalent) and search for leaks.
Fittings, lines, or components that appear to be oily
usually will indicate a refrigerant leak. To inspect
the evaporator core for leaks, it is possible to insert
the leak detector probe into the recirculating air door
opening (Fig. 6).
ADDING PARTIAL REFRIGERANT CHARGE
After all leaks have been corrected and it was not
necessary to empty the refrigerant system, a partial
refrigerant charge can be added.
CAUTION:Review all Safety Precautions and Warn-
ings before attempting to add refrigerant to the sys-
tem. Do not add refrigerant to a system that is
known to have a leak.
Fig. 5 Discharge Hose Adapter
24 - 10 HEATING AND AIR CONDITIONING Ä
