A monitoring system for a dual-stage, separated gas/fluid shock strut, comprising: a controller ; and a tangible, non-transitory memory configured to communicate with the controller, the tangible, non-transitory memory having instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations comprising: receiving, by the controller, a primary chamber temperature sensor reading; receiving, by the controller, a primary chamber pressure sensor reading; receiving, by the controller, a secondary chamber pressure sensor reading; receiving, by the controller, a shock strut stroke sensor reading; determining, by the controller, a shock strut stroke at which a secondary chamber of the shock strut is activated; calculating, by the controller, a volume of oil in an oil chamber of the shock strut based upon the shock strut stroke at which the secondary chamber of the dual-stage, separated gas/fluid shock strut is activated; calculating, by the controller, a primary chamber gas volume in a primary chamber of the shock strut based on the total internal volume of the shock strut in the fully extended position, the nominal volume of the secondary chamber when the shock strut is in the fully extended position and the calculated volume of oil in an oil chamber of the shock strut and calculating, by the controller, a primary chamber oil leakage volume of oil leaked into the primary chamber of the shock strut based on the primary chamber gas volume in the primary chamber and a primary chamber nominal dead volume. a controller ; and a tangible, non-transitory memory configured to communicate with the controller, the tangible, non-transitory memory having instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations comprising: receiving, by the controller, a primary chamber temperature sensor reading; receiving, by the controller, a primary chamber pressure sensor reading; receiving, by the controller, a secondary chamber pressure sensor reading; receiving, by the controller, a primary chamber temperature sensor reading; receiving, by the controller, a primary chamber pressure sensor reading; receiving, by the controller, a secondary chamber pressure sensor reading; receiving, by the controller, a shock strut stroke sensor reading; determining, by the controller, a shock strut stroke at which a secondary chamber of the shock strut is activated; calculating, by the controller, a volume of oil in an oil chamber of the shock strut based upon the shock strut stroke at which the secondary chamber of the dual-stage, separated gas/fluid shock strut is activated; calculating, by the controller, a primary chamber gas volume in a primary chamber of the shock strut based on the total internal volume of the shock strut in the fully extended position, the nominal volume of the secondary chamber when the shock strut is in the fully extended position and the calculated volume of oil in an oil chamber of the shock strut and calculating, by the controller, a primary chamber oil leakage volume of oil leaked into the primary chamber of the shock strut based on the primary chamber gas volume in the primary chamber and a primary chamber nominal dead volume. <EOS>