A refrigeration system servicing apparatus includes a digital controller, a vessel for storing and pressurizing refrigerant, a solenoid actuated valve responsive to the digital controller for selective connection of the refrigeration system to a vacuum source, a solenoid actuated valve responsive to the digital controller for connection of the vessel to the refrigeration system, a pressure sensor for providing pressure readings to the digital controller from the low pressure side of the vacuum source, a pressure sensor for providing pressure readings to the digital controller from the vessel and means for quantifying the refrigerant in the Vessel. Three operational modes provided for are: a "vacuum" mode, during which residue material in the refrigeration system is boiled away; a "charge oil" mode, during which lubricant is added to the refrigeration system; and a "charge refrigerant" mode, during which refrigerant is added to a refrigeration system. During vacuum mode the refrigeration system may be subjected to a pressure integrity test. Where in an inadequate vacuum is developed the error condition is signalled and the service technician is given opportunity to attempt correction. If a sufficient vacuum is developed, but cannot be held within a certain range for a minimum period the error condition is signalled and the service technician is again given opportunity to correct the condition, or to abort the operation.