Heating and Air Conditioning: Service Precautions
AIR CONDITIONING SYSTEMWHEN HANDLING REFRIGERANT
CAUTION
1. R-134a liquid refrigerant is highly volatile. A drop on the skin of your hand could result in localized frostbite. When handling the refrigerant, be sure to wear gloves.
2. It Is standard practice to wear goggles or glasses to protect your eyes, and gloves to protect your hands. If the refrigerant splashes into your eyes, wash them with clean water immediately
3. The R-134a container is highly pressurized. Never leave it in a hot place, and check that the storage temperature is below 52 °C (126 °F).
4. A electronic leak detector should be used to check the system for refrigerant leakage. Bear in mind that the R-134a, upon coming into contact with flame, produces phosgene, a highly toxic gas.
5. Use only recommended lubricant for R-134a systems. If lubricants other than the recommended one used, system failure may occur.
6. PAG lubricant absorbs moisture from the atmosphere at a rapid rate, therefore the following precautions must be observed:
- When removing refrigerant components from a vehicle, cap immediately the components to prevent from the entry of moisture.
- When installing refrigerant components to a vehicle, do not remove the cap until Just before connecting the components.
- Complete the connection of all refrigerant tubes and hoses without delay to prevent the A/C system from taking on moisture.
- Use the recommended lubricant from a sealed container only.
7. If an accidental discharge in the system occurs, ventilate the work area before resuming service.
WHEN REPLACING PARTS ON A/C SYSTEM
1. Never open or loosen a connection before discharging the system.
2. Seal the open fittings of components with a cap or plug immediately to prevent intrusion of moisture or dust.
3. Do not remove the sealing caps from a replacement component until it is ready to be installed.
4. Before connecting an open fitting always install a new sealing ring. Coat the fitting and seal with refrigerant oil before making the connection.
WHEN INSTALLING CONNECTING PARTS
1. BOLT/NUT COUPLING TYPE
1. Lubricate each connecting parts with compressor oil so as to tighten them easily, enough to prevent refrigerant leaks.
2. Use two wrenches not to twist the tube.
3. Tighten them to the specified torque.
2. FLANGE WITH GUIDE PIN TYPE
1. Check the O-ring for missing and damage, then lubricate it with compressor oil.
2. Push the pipe as shown in the illustration and tighten the nut by hand.
3. Tighten the nut to the specified torque.
COMPRESSOR OIL
The oil used to lubricate the compressor circulates in the system while the compressor is operating. Whenever replacing any component of the system or when a large amount of gas leakage occurs, add oil to maintain the original total amount of oil.
Compressor oil: 150 ± 10 cc
1. HANDLING OF OIL
1. The oil should be tree from moisture, dust, metal filings, etc.
2. Do not mix oils.
3. The moisture content in the oil increases when exposed to air for prolonged periods. After use, seal the container immediately
2. OIL RETURN OPERATION
To check the oil level or add oil, idle engine for 20-30 minutes and setting the heater control set to maximum cooling and blower level, to return the lubricant to compressor.
3. CHECKING AND ADDING COMPRESSOR OIL
In order to add oil to an operating compressor, check the compressor oil using the following procedure:
1. Perform the oil return operation, stop the engine, discharge the refrigerant, and dismantle the compressor from vehicle.
2. Discharge oil from the system line outlet.
NOTE: If compressor is cold, sometimes ft can be hard to drain the oil Warm up the compressor (approx. 40-50 °C) to drain the oil.
3. Check the amount of the discharged oil. If it is less than 70 cc, it means there is a little leak of oil. Perform the leakage test on each system connection, and repair or replace faulty parts if necessary.
4. Check oil for contamination and set the oil level in the procedure