Abstract: An environmentally sound apparatus and method for automatically extracting fluids such as lubricating fluids from a target reservoir such as a crankcase for a vehicle engine, and injecting the proper type and quantity of fresh fluid into the reservoir is disclosed. The apparatus includes one or more sources of lubricating fluid, a waste fluid tank, a pump, and a flow meter. A programmed microprocessor produces selected sequences of control signals to govern the flow of fluid among the fluid sources, the waste fluid tank, and the target reservoir in response to input identification information and signals produced by a flow monitoring pulse meter. Input identification information is compared with data in a stored database to determine the correct type and quantity of fresh fluid to inject. Operator identification information is compared with a stored operator database to determine what operations each operator is permitted to perform.