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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. |
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Personal injury can result from hot coolant. Any contact with hot coolant or with steam can cause severe burns. Allow cooling system components to cool before the cooling system is drained. |
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Never weld or solder any charged components. |
The following is a list of general concerns and comments regarding the function of the air conditioning and heating systems. Additional information can be found in the troubleshooting articles that are specific to troubleshooting each system.
- Low refrigerant charge causes a loss of cooling ability and lubrication in the compressor, resulting in failure of the compressor.
- Overcharge of refrigerant will cause a loss of cooling ability. A system that is overcharged will contain excess liquid refrigerant, which will severely damage the compressor.
- The appearance of frost does not always indicate a failure. Refer to Testing and Adjusting, UENR4125, "Air Conditioning Performance - Test" to diagnose a blockage in the air conditioning system properly.
- A small amount of moisture will penetrate the hoses that are used in R134a systems. Replace the dryer or replace the accumulator that is containing the desiccant according to recommendations in Systems Operation, UENR4125, "Service Intervals".
- Formation of black sludge deposits is caused by the presence of moisture in R134a systems.
A loss of cooling ability of the system and failure of the compressor may be caused by one or more of the following conditions.
- Low charge
- Overcharge
- Too much oil
- Too little oil
- Dirty filter or plugged filter
- Dirty condenser or plugged condenser
- Dirty evaporator or plugged evaporator
- Dirty orifice tube or plugged orifice tube
- Dirty expansion valve or plugged expansion valve
- Too much moisture in the system
- Missing drain valves for the evaporator