Subaru Impreza 2002 Service Manual page 3181

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
4. Refrigerant Charging Proce-
dure
A: OPERATION
CAUTION:
• During operation, be sure to wear safety gog-
gles and protective gloves.
• Before charging the refrigerant, evacuate the
system to remove small amounts of moisture
remaining in the system.
The moisture in the system can be completely
evacuated only under the minimum vacuum
level. The minimum vacuum level affects the
temperature in the system.
• The list below shows the vacuum values nec-
essary to boil water in various temperature. In
addition, the vacuum levels indicated on the
gauge are approx. 3.3 kPa (25 mmHg, 0.98 inHg)
lower than those measured at 304.8 m (1,000 ft)
above sea level.
Vacuum level required to boil water (at sea level)
Temperature
1.7°C (35°F) 100.9 kPa (757 mmHg, 29.8 inHg)
7.2°C (45°F) 100.5 kPa (754 mmHg, 29.7 inHg)
12.8°C (55°F) 99.8 kPa (749 mmHg, 29.5 inHg)
18.3°C (65°F) 99.2 kPa (744 mmHg, 29.3 inHg)
23.9°C (75°F) 98.5 kPa (739 mmHg, 29.1 inHg)
29.4°C (85°F) 97.2 kPa (729 mmHg, 28.7 inHg)
35°C (95°F) 95.8 kPa (719 mmHg, 28.3 inHg)
1) Close the valves on low-/high-pressure sides of
the manifold gauge.
2) Install the low-/high-pressure hoses to the corre-
sponding service ports on the vehicle respectively.
3) Connect the center hose of the manifold gauge
set with the vacuum pump.
REFRIGERANT CHARGING PROCEDURE
Vacuum
G4M0596
4) Carefully open the valves on the low-/high-pres-
sure sides to activate the vacuum pump.
5) After the low-pressure gauge reaches 100.0 kPa
(750 mmHg, 29.5 inHg) or higher, evacuate the
system for approx. 15 minutes.
6) After 15 minutes of evacuation, if the reading
shows 100.0 kPa (750 mmHg, 29.5 inHg) or higher,
close the valves on the both sides to stop the vac-
uum pump.
7) Note the low-pressure gauge reading.
AC-22
G4M0597
G4M0598
G4M0599
G4M0600