Abstract: A rotary shaft sealing system comprising a rotary lip seal and its associated retention gland, wherein the each of the seal and the gland are complimentary of the other within the environment of use. The system is particularly adapted for the sealing of a rotary shaft in an environment wherein the hydraulic pressure upon the fluid within the gland is at least 20 psi, or higher; and, such fluid pressure within the gland is further subject to variation or surges at the time of start-up and/or during operation/use of the rotary shaft. The retention gland geometry assists in the direction and application of hydraulic pressure against the seal so as to increase the radial contact force between the seal lip and the rotary shaft, thus, insuring more complete and effective sealing at this contact interface. The seal of this system is preferable pre-loaded so as to apply positive sealing pressure against the rotary shaft both prior to and during use.