A joint enclosure apparatus includes a dust boot having an opening and a rim located adjacent to the opening, a flexible flap formed as a portion of the rim, and at least one grease relief passage located on an outer surface of the dust boot adjacent to the flexible flap. The dust boot is useful for use in a ball joint assembly which includes a ball stud having a shank portion and a ball portion; a housing adapted to receive the ball portion in articulatable engagement in a ball stud exit end; a dust boot having a shank opening in sealing engagement with the shank portion and a housing opening in sealing engagement with the housing at the ball stud exit end and a rim adjacent to the shank opening; a flexible flap formed as a portion of the rim; and at least one grease relief passage located on an outer surface of the dust boot adjacent to the flexible flap. The grease relief passage may comprise a rib or a recessed channel. The area of the outer surface of the dust boot adjacent to the flexible lip may be undercut to control the relief characteristics of the flexible lip. As grease is flushed from the dust boot, it is directed along a path defined by the grease relief passage. If a dust boot becomes pinched during stud articulation, the grease relief passage provides an escape path for grease after it passes the flap.