Air Conditioning and Heating R-12 All Caterpillar Machines – Refrigerant Recovery

------ 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.


If service work is required on an air conditioning system, the refrigerant must be recovered first before components are removed or installed. Use the following procedure:

  1. Use the refrigerant identifier. The refrigerant identifier will detect refrigerants that are not R-12. The refrigerant identifier will prevent the refrigerants from contaminating the tools for recovery and the tools for charging. The refrigerant identifier will also detect the percentage of air that may be in the system.

    Illustration 1 g00389232

    (1) Low pressure valve

    (2) High pressure valve

    (3) Charging hose

    (4) Low pressure hose

    (5) High pressure hose

    (6) Manifold gauge set

    (7) Control panel

    (8) Inlet on recovery station

    (9) Accumulator/oil separator

    (10) Drain valve

    (11) Pressure valve on accumulator

    (12) Compressor

    (13) Refrigerant tank

    (14) Hose (liquid)

    (15) Hose (vapor)

    (16) Refrigerant pump

    (17) Filter dryer

    (18) Scale

    (A) Refrigerant compressor

    (B) Low pressure side (suction)

    (C) High pressure side (discharge)

  1. Install the manifold gauge set (6). Make sure that both valves are closed. Turn the valves clockwise in order to close the valves. Refer to theTesting and Adjusting, “Manifold Gauge Set (Refrigerant) – Install” section.

    Note: Do not operate the engine.

  1. Attach charging hose (3) of the Manifold gauge set to the inlet (8) on the refrigerant service unit.
  1. Slowly open valves (1) and (2) in order to release the air from the charging hose. Ensure that the valves on the refrigerant tank (13) are open. One valve is for vapor and the other valve is for liquid.
  1. Plug the recovery station into an electrical outlet and turn the power switch ON. This switch is located on the control panel (7) .
  1. Press the “Compressor Start”. The amber “Compressor On” light will come on and compressor (12) will start. The compressor will automatically shut off when the recovery of refrigerant is complete.
  1. Drain accumulator (9) of refrigerant oil. Open accumulator pressurizing valve (11) long enough so that some discharge from the compressor can flow back to the accumulator. Open oil drain valve (10) slowly and drain the oil into a measuring cup. Do not allow a complete loss of pressure in the accumulator/oil separator. When the oil stops draining, close oil drain valve (10) .
  1. If 15.0 mL (.50 fl oz) of compressor oil was lost during the recovery process, new oil must be added to the system. Refer to the Testing and Adjusting, “Refrigerant Compressor Oil – Check” section.
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