CAUTION
By law; in the manner as recommended by the manufacturer, only certified HVAC technicians can legally perform operations that involve installation and/or the removal/recovery of vehicle refrigerant. This is true of any and all operations that involve the potential exposure of vehicle refrigerant into the atmosphere.
Safety is the most important factor when performing not only fuel system maintenance but also any type of maintenance. Failure to conduct maintenance and repairs in a safe manner may result in serious personal injury or death.
- To avoid the possibility of fire and personal injury, always disconnect the negative battery cable unless the repair or test procedure requires that battery voltage be applied.
- Always relieve the fuel system pressure prior to disconnecting any fuel system component (injector, fuel rail, pressure regulator, etc.), fitting or fuel line connection. Exercise extreme caution whenever relieving fuel system pressure, to avoid exposing skin, face and eyes to fuel spray. Please be advised that fuel under pressure may penetrate the skin or any part of the body that it contacts.
- Always place a shop towel or cloth around the fitting or connection prior to loosening to absorb any excess fuel due to spillage. Ensure that all fuel spillage (should it occur) is quickly removed from engine surfaces. Ensure that all fuel soaked cloths or towels are deposited into a suitable waste container.
- Always keep a dry chemical (Class B) fire extinguisher near the work area.
- Do not allow fuel spray or fuel vapors to come into contact with a spark or open flame.
- Wear eye protection when servicing the air conditioning refrigerant system. Serious eye injury can result from eye contact with refrigerant. If eye contact is made, seek medical attention immediately.
- Do not expose refrigerant to open flame. Poisonous gas is created when refrigerant is burned. An electronic type leak detector is recommended.
- Large amounts of refrigerant released in a closed work area will displace the oxygen and cause suffocation.
- The evaporation rate of refrigerant at average temperature and altitude is extremely high. As a result, anything that comes in contact with the refrigerant will freeze. Always protect skin or delicate objects from direct contact with refrigerant. R-134a service equipment or vehicle A/C system should not be pressure tested or leak tested with compressed air.
- Some mixtures of air and R-134a have been shown to be combustible at elevated pressures. These mixtures are potentially dangerous and may result in fire or explosion causing injury or property damage.
- Antifreeze is an ethylene glycol base coolant and is harmful if swallowed or inhaled. Seek medical attention immediately if swallowed or inhaled. Do not store in open or unmarked containers. Wash skin and clothing thoroughly after coming in contact with ethylene glycol. Keep out of reach of children and pets.
- Do not open a cooling system when the engine is at running temperature. Personal injury can result.
- Kinks in the refrigerant tubing or sharp bends in the refrigerant hose lines will greatly reduce the capacity of the entire system.
- High pressures are produced in the system when it is operating. Extreme care must be exercised to make sure that all connections are pressure tight. Dirt and moisture can enter the system when it is opened for repair or replacement of lines or components. The refrigerant oil will absorb moisture readily out of the air. This moisture will convert into acids within a closed system.
- The system must be completely empty before opening any fitting or connection in the refrigeration system. Open fittings with caution even after the system has been emptied. If any pressure is noticed as a fitting is loosened, retighten fitting and evacuate the system again.
- A good rule for the flexible hose lines is to keep the radius of all bends at least 10 times the diameter of the hose. Sharper bends will reduce the flow of refrigerant. The flexible hose lines should be routed so they are at least 3 in (80 mm) from the exhaust manifold. Inspect all flexible hose lines to make sure they are in good condition and properly routed.
- The use of correct wrenches when making connections is very important. Improper wrenches or improper use of wrenches can damage the fittings.
- The internal parts of the A/C system will remain stable as long as moisture-free refrigerant and refrigerant oil is used. Abnormal amounts of dirt, moisture or air can upset the chemical stability. This may cause operational troubles or even serious damage if present in more than very small quantities.
- When opening a refrigeration system, have everything you will need to repair the system ready. This will minimize the amount of time the system must be opened. Cap or plug all lines and fittings as soon as they are opened. This will help prevent the entrance of dirt and moisture. All new lines and components should be capped or sealed until they are ready to be used.
- All tools, including the refrigerant dispensing manifold, the manifold gauge set, and test hoses should be kept clean and dry.
- It should be understood that proper cleaning and protection of machined surfaces and friction areas is part of the repair procedure. This is considered standard shop practice even if not specifically stated.
- When any internal engine parts are serviced, care and cleanliness is important.
- When components are removed for service, they should be marked, organized or retained in a specific order for reassembly.
- At the time of installation, components should be installed in the same location and with the same mating surface as when removed.
- An automobile engine is a combination of many machined, honed, polished and lapped surfaces with tolerances that are measured in millimeters or thousandths of an inch. These surfaces should be covered or protected to avoid component damage.
- A liberal coating of clean engine oil should be applied to friction areas during assembly.
- Proper lubrication will protect and lubricate friction surfaces during initial operation.
CAUTION
By law only certified HVAC technicians can legally perform operations that involve installation and/or the removal/recovery of vehicle refrigerant. This is true of any and all operations that involve the potential for releasing of refrigerant into the atmosphere.
