Abstract: A normally closed drain valve is substituted for the normal drain plug in a conventional automobile crank case. Rather than remove the normally provided drain plug each time the oil is to be drained, it is only necessary to open the drain valve. Opening of this valve is accomplished by a specially designed coupler connected to a plastic bag. The arrangement is such that when the coupler is urged over the drain valve and twisted, the valve automatically opens to fill the bag with oil. The coupler can then be twisted back to its original position to close the drain valve and removed with the bag containing the oil. The entire operation can be accomplished only using one hand and with substantially no risk of oil spilling or soiling the operator.