An isolation tool is presented for use in fluidly isolating first and second sections of tubing and more typically to a bleed valve/port of a gas lift mandrel. The isolation tool is configured for disposition within an interior of a gas lift mandrel. The isolation tool includes one or more resilient elements that may be compressed to expand to and seal against an inside surface of the tubing/mandrel. Such expansion and sealing by the resilient element(s) fluidly isolates sections of the tubing/mandrel. The isolation tool may be removed through the tubing when desired by releasing the compression of the resilient element(s) such that the resilient element(s) disengage the inside surface of the tubing/mandrel.