Technician Safety Information

Because an engine cooling system at normal running temperatures will generate internal pressure of 97 - 124 kPa (14 - 18 psi), extreme caution should be used when servicing any engine cooling system related components.

ABOUT REFRIGERANT 12 (R12)

Refrigerant 12 (R12) is used to charge the A/C system. It is colorless and transparent in both the liquid and vapor state. It has a boiling point of -21.7 °F (-29.8 °C), at atmospheric pressure, so it will be a vapor at all normal temperatures and pressures. This vapor is heavier than air, nonflammable and nonexplosive.

It is not corrosive except when combined with water. It is not poisonous except when it is in direct contact with open flame.

R12 leaves the can as liquid in upside down position and leaves as a vapor in upright position.

R12 evaporates so rapidly at normal atmospheric pressures and temperatures, that it freezes anything it contacts. Extreme care must be taken to prevent it from touching the skin and especially the eyes.

Always wear safety goggles when servicing the refrigeration part of the air conditioning system. Keep a bottle of sterile mineral oil handy when working on the refrigeration system. Should any liquid refrigerant get into the eyes, use a few drops of mineral oil to wash them out. Refrigerant 12 is rapidly absorbed by the oil. Next, splash the eyes with plenty of cold water. Call your doctor immediately even though irritation has ceased after first aid treatment.

Do not heat refrigerant 12 above 125 °F (52 °C). The can may explode.

Moderate heat is required to bring the pressure of the refrigerant in its can above the pressure of the system when charging or adding refrigerant. Usually a pan of hot water not over 125 °F (52 °C) is all the heat required for this purpose. Never heat the refrigerant with a blow torch or by any other means which would raise the temperature and pressure above this temperature. Don't steam clean or weld on or near system components or refrigerant lines.

NOTE: Keep (R12) containers upright when charging system.

NOTE: Always maintain good ventilation in servicing area. Discharge refrigerant into the service bay exhaust system only. Too much refrigerant in a small poorly ventilated room can cause suffocation.

NOTE: A poisonous gas is produced when using a flame-type leak detector.

NOTE: Liquid refrigerant will tarnish bright metal and chrome surfaces.

CAUTION: Never use these cans to charge into the high pressure side of the system (Compressor discharge port) or into a system that is at high temperature, Because the high system pressures could be transferred into the charging can causing it to explode.

Caution should be exercised whenever working with spring or tension loaded fasteners such as E-Clips, Circlips, Snap rings etc. as careless removal can cause injury.

ABOUT ELECTRONIC LEAK DETECTION

Do not allow the leak detector probe to come into contact with liquids. Liquids mask leaks and shorten sensor life.

Do not perform leak detection in an area with excessive airflow.

Do not come into contact with windshield washer fluid, paint and mastic fumes, excessive dust, halogenated solvents, or other contaminants. Contact with these, causes risk of erratic instrument operation or false readings.

When checking for leaks, position tester probe under the component, because refrigerant is heavier than air.

EXERCISE SYSTEM

An important fact most owners ignore is that A/C units must be used periodically. Manufacturers caution that when the air conditioner is not used regularly, particularly during cold months, it should be turned on for a few minutes once every two or three weeks while the engine is running. This keeps the system in good operating condition.

Checking out the system for effects of disuse before the onset of summer is one of the most important aspects of A/C servicing.

First clean out the condenser core, mounted in all cases in front of the radiator. All obstructions, such as leaves, bugs and dirt, must be removed, as they will reduce heat transfer and impair the efficiency of the system. Make sure the space between the condenser and the radiator is also free of foreign matter.

Make certain the evaporator water drain is open. The evaporator cools and dehumidifies the air before it enters the passenger compartment; there, the refrigerant is changed from a liquid to a vapor. As the core cools the air, moisture condenses on it but is prevented from collecting in the evaporator by the water drain.