Abstract: This invention relates to a grouting tube for packer designed to prevent back-flow of cement grouting material past the grout packer out of the grouting area. The grouting tube is comprised essentially of an innertube constructed of steel or like material through which the grouting material is designed to flow. The inner tube has threaded nut means disposed a distance from the upper end of the tube on reverse threads. At the other or lower end of the tube, a retaining ring means is disposed and attached to said bottom end by means of rivets or the like. Concentric with said inner tube and disposed between said ring and said nut means is a series of alternating frusto-conical tubes and flexible frusto-conical leather caps. The caps are designed to act as seals between the grouting tube and the walls of the grout hole to prevent backflow of grouting material.