DISC-ORIFICE 1501764 - Caterpillar

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.
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.
Note: Refer to Systems Operation Section, "General Information" for the air conditioning system service port locations for your machine.
Close both manifold valves on the manifold gauge set by turning the valves fully clockwise. Close both service valves on the service couplers by turning the control knob fully counterclockwise. Note: Make sure that the manifold valves and the service coupler valves are closed before installing the manifold gauge set. Always install the manifold gauge set with the engine OFF.
Remove the protective cap from the high-pressure service port located on the discharge side of the refrigerant compressor. Connect the high-pressure side service coupler valve onto the service port.
Remove the protective cap from the low-pressure service port located on the suction side of the refrigerant compressor. Connect the low-pressure side service coupler valve onto the service port.
Open both of the service coupler valves by turning the control knobs clockwise.
Loosen the charging hose fitting at the auxiliary port of the manifold gauge set. Place a clean rag over the charging hose fitting in order to prevent the spraying of compressor oil. Note: Be careful not to allow refrigerant to spray on bare skin. Refrigerant will freeze skin tissue on contact.
Open the low-pressure manifold valve on the manifold gauge set about