• Whenever the air conditioning system has been exposed to the atmosphere, it must be evacuated.
• After installation of a component, the system should be evacuated for approximately 15 minutes. A component in service that has been opened for repair should be evacuated for 30 minutes.
1. EVACUATE SYSTEM
(a) Connect the manifold gauge set. (See page AC-11)
(b) Install the center hose of gauge set on the vacuum pump inlet.
(c) Run the vacuum pump, and then open both hand valves.
(d) After about ten minutes, check that the low pressure gauge reads more than 600 mmHg (23.62 in. Hg, 80.0 kPa) of vacuum.
If the reading is not more than 600 mmHg (23.62 in. Hg,
80.0 kPa), close both valves and stop the vacuum pump.
Check the system for leaks and repair as necessary.
If no leakage is found, continue evacuating the system.
(e) After the low pressure gauge indicates more than 700 mmHg (27.56 in. Hg, 93.3 kPa) of vacuum, continue evacuating for 15 minutes.
(f) Close both hand valves, and stop the vacuum pump. Disconnect the hose from the vacuum pump.
The system is now ready for charging.
2. INSTALL REFRIGERANT CONTAINER TAP VALVE
CAUTION: Observe the precautions listed in the front of this section.
(a) Before installing the valve on the refrigerant container, turn the handle counterclockwise until the valve needle is fully retracted.
(b) Turn the disc counterclockwise until it reaches its highest position.
Screw down the valve on the refrigerant container.
(c) Connect the center hose to the valve fitting. Turn the disc fully clockwise by hand.
(d> Turn the handle clockwise to make a hole in the sealed tap.
(e) Turn the handle fully counterclockwise to fill the center hose with gas. Do not open the high and low pressure valves.
(f) Loosen the center hose nut connected to the center fitting of the manifold gauge until a hiss can be heard. Allow air to escape for a few seconds, and then tighten the nut.
3. TEST SYSTEM FOR LEAKS
NOTE: After evacuating the system, check for leaks.
(a) Install the refrigerant container tap valve as described in step 2.
(b) Open the high pressure valve to charge the system with refrigerant vapor.
(c) When the low pressure gauge reads 1 kg/cm2 (14 psi, 98 kPa), close the high pressure valve.
(d) Using a halide gas leak detector, propane torch, or electric leak detector, check the system for leaks.
If a leak is found, repair the faulty component or connection.
(e) After checking and repairing the system, perform the following:
• Turn the container tap handle fully clockwise.
• Disconnect the center hose from the can valve fitting.
• Evacuate the system for at least 15 minute. (See step 1 on page AC-12)
4. CHARGE EMPTY SYSTEM (LIQUID)
NOTE: This step is to charge an empty system through the high pressure side with refrigerant in a liquid state. When the refrigerant container is held upside down, refrigerant will enter the system as a liquid.
• Never run the engine when charging the system through the high pressure side.
• Do not open the low pressure valve when the system is being charged with liquid refrigerant.
(a) Close both high and low pressure valves completely after the system is evacuated.
(b) Install refrigerant container tap valve as described in step 2.
(c) Open the high pressure valve fully, and keep the container upside down.
(d) Charge the system with more than one container (400 g, 0.9 lb) than the specified amount. Then, close the high pressure valve.
• A fully charged system is indicated by the receiver sight glass being free of any bubbles.
• If the low pressure gauge does not show a reading, the system is clogged and must be repaired.
5. CHARGE EMPTY SYSTEM OR PARTIALLY CHARGED
• This step is to charge the system through the low pressure side with refrigerant in a vapor state. When the refrigerant container is placed rightside up, refrigerant will enter the system as a vapor.
• Put the refrigerant container in a pan of warm water (maximum temperature 40° C or 104°F) to keep vapor pressure in the container slightly higher than vapor pressure in the system.
(a) Install refrigerant container tap valve as described in step 2.
(b) Open the low pressure valve. Adjust the valve so that the low pressure gauge does not read over 4.2 kg/cm3 (60 psi, 412 kPa).
(c) Run the engine at fast idle, and operate the air conditioner.
CAUTION: Be sure to keep the container in the upright position to prevent liquid refrigerant being charged into the system through the suction side, resulting in possible damage to the compressor.
(d) Charge the system with more than one container (400 g, 0.9 lb) than the specified amount. Then, close the low pressure valve.
NOTE: A fully charged system is indicated by the receiver sight glass being free of any bubbles.
6. IF NECESSARY, CHARGE SYSTEM WITH ANOTHER
(a) When the refrigerant container is empty, close the pressure valves.
(b) Remove the container tap valve from the container.
(c) Attach the container tap valve to a new refrigerant container.
(d) Purge the air from the center hose by barely opening the low pressure valve and loosening the valve disc.
(e) Make a hole in the sealed tap of the new container and charge the system.
CAUTION: Be careful not to overcharge the refrigerant as it may cause failure of the bearings and belt.
7. WHEN SYSTEM IS FULLY CHARGED, DISCONNECT
MANIFOLD GAUGE SET
(a) Close both low and high pressure valves.
(b) Close valve at refrigerant container. If using one pound containers of R-12, allow remaining refrigerant to escape by slowly removing the charge line.
(c) Turn off the engine.
(d) Using a shop rag, quickly remove both hoses from the compressor service valves.
WARNING: Care must be taken to protect eyes and skin when removing the high pressure hose.
(e) Put the cap nuts on the service valve fittings.
Air Intake Control Lever
Air Intake Control Lever
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