MANUAL & SEMIAUTO-HVAC 7B/C-11
Evacuating Refrigeration System
1. Connect the manifold gauge to the charging valves.
2. Connect the center hose of the gauge to the vacuum pump.
3. Run the vacuum pump and open both high and low pressure
hand valves.
4. Run the vacuum pump 15-20 minutes.
5. Check that both high and low pressure gauge reading is
more than (-) 750mmHg of vacuum and close both valves.
Check for Refrigerant Leaks
1. Connect the center hose of the gauge to the refrigerant
tank.
2. Open the high pressure valve of the gauge to charge with
refrigerant gas.
3. Charge until the low pressure gauge reads 1.0kg/cm and
close the valve.
4. Using a gas leak detector, check the system for leaks.
5. If a leak is found, replace a O-ring or repair the faulty
connection
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6. Stop the vacuum pump and wait about 5 minutes.
7. After 5 minutes, check that low pressure gauge reading is
changed or not.
8. If low pressure gauge reading is changed, check the system
for leaks and repair as necessary and repeat steps from
‘1’ to ‘7’.
9. If there are no changes in low pressure gauge reading,
disconnect the vacuum pump.
4. After the high pressure gauge reading drops below 3.5kg/
cm2 , slowly open the low pressure valve.
5. When both high and low pressure gauges reading drops to
0 kg/cm, discharging is completed.
7B/C-12 MANUAL & SEMIAUTO-HVAC
Charging Refrigerant
1. Connect the manifold gauge to the charging valve and
evacuate the system.
2. Connect the center hose of the gauge to the refrigerant
tank.
3. Open the high pressure valve and charge the system with
350g of refrigerant.
4. Close the high pressure valve and start the engine and run
the compressor.
Notice
Never open the high pressure valve when the compressor
is running. Refrigerant gas will be charged reverse.
5. Slowly open the low pressure valve and charge the system
with refrigerant.
Standard650 - 750 g
6. Close the low pressure valve after charging.
Notice
Checking the pressure through the sight glass is impossible
by applying & R-134a.
7. Stop the engine and disconnect the manifold gauge from
the system.
Operation Check
1. Place a dry bulb thermometer to the front duct.
2. Place a psychrometer close to the inlet of the cooling unit
(under the glove box).
3. Run the engine at 1,500 rpm.
4. Set the blower switch at ‘HI’ and A/C switch ‘ON”.
5. Set the temperature control lever at ‘COOL’.
6. Set the air flow control at ‘REC’.
7. Check that air conditioning system is stabilized.
Temperature of Air Inlet
High Pressure Gauge Reading 25 - 35°C
13.2 - 18.5kg/cm
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