Heating and Air Conditioning: Service Precautions
WHEN HANDLING REFRIGERANT
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. If the refrigerant splashes into your eyes, wash them with clean water immediately. It is standard practice to wear goggles or glasses to protect your eyes, and gloves to protect your hands.
3. The R-134a container is a highly pressurized, never leave it in a hot place, and check that the storage temperature is below 52° C (126° F).
4. A halide leak detector is often used to check the system for refrigerant leakage. Bear in mind that R-134a upon coming into contact with flame (this detector burns propane to produce a small flame), produces phosgene a toxic gas.
5. R-134a refrigerant and R-12 refrigerant must never be mixed, even in the smallest amounts, as they are incompatible with each other If the refrigerants are mixed, compressor failure is likely to occur.
6. Use only recommended lubricant for R-134a A/C system and components. If lubricants other than recommended one used, system failure may occur.
7. The 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 A/C system 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 entry of moisture.
- Use the recommended lubricant from a sealed container only.
8. If accidental system discharge 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 with a cap or plug immediately in disconnected parts 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.
5. Because of the differences in the physical properties and characteristics between R-12 and R-134a refrigerants, the compressor oil for lubricating the air compressor and other system parts are not interchangeable between the R-12 and R-134a systems. Use the utmost care to avoid using the wrong ones. The compressor oils and some other materials are not visually distinguishable. To avoid any misuse, be sure that the materials for the R-12 system and those for the R-134a system are separately controlled.
- If an O-ring usable only for the R-12 system is used for the R-134a system by mistake, the O-ring will foam and swell, subsequently causing the refrigerant to leak.
- If the compressor oil specified for use in the R-12 system is inadvertently used for the R-134a system, the compressor will lock.
WHEN INSTALLING CONNECTING PARTS
FLANGE WITH GUIDE PIN TYPE
1. Check the condition (damages or missing) of the O-ring and lubricate using compressor oil. Hand tighten the nut by pushing the one side pipe. Tighten the nut to specified torque.