Air Conditioning and Heating R-12 All Caterpillar Machines – Manifold Gauge Set (Refrigerant) – Remove

------ WARNING! ------

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.


Remove charging hoses properly. A low system charge will result from charging hoses that are not removed correctly. In order to ensure accuracy of the refrigerant charge, the refrigerant should be removed from the charging hoses. Refer to the following steps in order to remove the refrigerant from the charging hoses:

  1. Allow the compressor to continue operating. Close the valve on the high pressure side. The valve is located near the charging ports on the compressor. Disconnect the high pressure hose from the air conditioning system.
  1. Open the high pressure valve and open the low pressure valve at the gauge set. The refrigerant that is in the hoses will be removed by the compressor through the low pressure hose.
  1. Close the valve on the low pressure side. This valve is located near the charging ports on the compressor. Disconnect the low pressure hose from the air conditioning system. The system is now charged.

Note: After the manifold gauge set is removed, it is necessary to cap the charging valves.

Posted in D6Tagged