PLUG 9U7110 - Caterpillar

Identifying The System
Examine the charging ports. If one port is smaller than the other port, the air conditioning system contains R-134a refrigerant.
Illustration 1 g00291316
(1) Block fitting at compressor with R-134a charging ports
If the machine has R-134a charging ports, a tag should identify the type of compressor oil that is used. The tag can be located inside the cab. The tag may also be located near the compressor. The tag will also display the amount of refrigerant in the system. If the machine was delivered from the factory with R-134a refrigerant, the tag will display PAG (Polyalkylene Glycol). PAG oil is the lubricant for the system. Glossary of Terms
Ambient air - Outside airCharge - The charge is a predetermined amount of refrigerant that is put into the air conditioning system by weight.Compressor - The compressor is a component in the system that increases the pressure of the refrigerant in the system by pumping.Condenser - The condenser is a component in the system that changes the refrigerant from gas to a liquid.Contaminants - Dirt, water and airDesiccant - The desiccant is part of the receiver or the accumulator that removes the moisture from the air conditioning system. Detecting - Detecting is finding the source of the problem in the system.Diaphragm - The diaphragm is a rubber-like material. The diaphragm divides the upper chamber and the lower chamber in the thermostatic expansion valve.Discharge - The discharge is the removal of some of the refrigerant or the removal of all the refrigerant from the air conditioning system.Discharge side - The discharge side is the outlet from the compressor to the condenser coil.Evacuating - Evacuating is the removal of air and moisture from the air conditioning system. Evaporation - Evaporation is the process of changing a liquid to a vapor.Evaporator - The evaporator is the component in the air conditioning system that changes the refrigerant from a liquid to a gas by the addition of heat. Expansion Valve - The expansion valve is a component in the air conditioning system that regulates the flow of liquid refrigerants into the evaporator.Fluid - Fluid is a liquid or a gas.Formation of Bubbles - Bubbles in the sight glass of the receiver-dryer implies that too little refrigerant remains.Flush - To remove foreign material and oil from the system, you must flush the system with fluid that is approved. The fluid must be approved by the SAE standard and approved by the ISO standard.Freeze - Freezing can cause a liquid to become a solid.Gas - gas is a vapor which contains no liquid.Graduated Container - A graduated container is a glass scale that is used to measure a fluid in ounces or milliliters.Heat - Thermal energyIdentifier - The identifier is an instrument for testing the system. The identifier is used for determining the type of refrigerant in the system. The identifier is also used for determining the percent of air in the system.In-line dryer - A component of the air conditioning system that removes contaminants (moisture) from the