Air Conditioning and Heating R-12 All Caterpillar Machines Caterpillar

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Personal injury can result from contact with refrigerant. This system is under pressure at all times, even if the engine is not running. Heat should never be applied to a charged system. Contact with refrigerant can cause frost bite. Keep face and hands away to help prevent injury. Protective goggles must always be worn when refrigerant lines are opened, even if the gauges indicate the system is empty of refrigerant. Always use caution when a fitting is removed. Slowly loosen the fitting. If the system is still under pressure, evacuate the system recovering the refrigerant before removing the fitting. Personal injury or death can result from inhaling refrigerant through a lit cigarette. Inhaling air conditioner refrigerant gas through a lit cigarette or other smoking method or inhaling fumes released from a flame contacting air conditioner refrigerant gas, can cause bodily harm or death. Do not smoke when servicing air conditioners or wherever refrigerant gas may be present. Before any checks of the air conditioning and heating system are made, move the machine to a smooth horizontal surface. Lower all implements to the ground. Make sure the transmission is in neutral or park and that the parking brake is engaged. Keep all other personnel away from the machine or where they can be seen.

When the service work is done on the air conditioning system, it is important to keep the system clean and free from contamination. Plugs and caps must be used in order to close the components and hoses when the components and hoses are open. The plugs and caps protect the system from dirt and air (moisture). Only new refrigerant oil of the correct viscosity and new refrigerant can be added to the system. Refer to the Service Manual, SENR3334, "Refrigerant Compressor" section in this manual for the correct oil. Any other material or any other substance is considered non-condensable and the material will contaminate the system. Keep the work area clean.

• Dust caps on the refrigerant compressor block fitting are the primary seal on the air conditioning system.

• All machines should have an identification tag in the cab that specifies the proper refrigerant charge for the machine.

When replacement or repair of components and hoses are required, perform the following procedure:

1. Remove the refrigerant charge. Refer to the Service Manual, SENR3334, "Refrigerant Recovery" section in Testing and Adjusting.

2. Remove the component or remove the hose that is being repaired or replaced. Install protective plugs on components or hoses that are left exposed to the air.

3. Replace any damaged component or hose.

4. Use the following table in order to determine the amount of oil that is lost during individual replacements of components. Add the correct amount of oil to the compressor before the system is evacuated. No additional oil should be added to the system if the compressor is replaced at the same time as other components in the system.
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   Table 1

   Oil Capacities for Component Replacements
   Accumulator	30 mL (1 fl oz)
   Compressor	Refer to the Service Manual, SENR3334, "Refrigerant Compressor Oil-Check" section in Testing and Adjusting.
   Condenser	30 mL (1 fl oz)
   Evaporator	90 mL (3 fl oz)
   In-Line Dryer (1)	30 mL (1 fl oz)
   Receiver-Dryer	30 mL (1 fl oz)

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   Refer to the Service Manual, SENR3334, "In-Line-Refrigerant Dryer - Remove and Install " before any oil is added.

5. Refer to the Service Manual, SENR3334, "Refrigerant System-Evacuate" section in testing and adjusting.

6. Refer to the Service Manual, SENR3334, "Refrigerant System-Charge" section in Testing and Adjusting.