DIFFERENTIAL & BEVEL GEAR GP 4716991 - 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.
If replacement of a component is necessary or repair to a component is necessary, the refrigerant in the system must be recovered. Also, if the system has lost any charge after a long period of time, the refrigerant in the system must be recovered. It is necessary to perform the evacuating procedure in order to delete the system of all air and moisture. A complete charge must never be given to a system without first performing the evacuating procedure. Before evacuating the system, refer to the following manual.
Testing and Adjusting, SENR3334, "Refrigerant Leakage - Test"
Testing and Adjusting, SENR3334, "Refrigerant Recovery"
Testing and Adjusting, SENR3334, "Refrigerant Compressor Oil - Check"If the system has been left open for more than 1/2 hour, the system has been exposed to air or moisture and a new receiver-dryer, an in-line dryer or a desiccant accumulator needs to be installed. Moisture will combine with metals in the refrigerant system and this will produce highly corrosive by-products. The by-products are oxides, iron hydroxide, and aluminum hydroxide. Moisture can freeze the expansion valve and moisture can freeze the orifice tube. If there is water in the system the water must be removed. Remove the water by pumping the system with a vacuum pump and boiling the water. Refer to Table 1 that is shown below.The time for the evacuation process will increase under the following conditions:
The air conditioning system has been rebuilt.
The air conditioning system has been flushed.
The air conditioning system has new components.
The air conditioning system has been retrofitted.
Table 1
Boiling Point of Water Under Vacuum    
Temperature of Work Area (°C (°F))    Vacuum That Is Required In Order To Boil Water In An Air Conditioning System (m bar (Hg))    
38 °C (100 °F)    
95 kPa (28 in Hg)