A system for pressurizing a hub having a bearing chamber formed from an air-tight sealing arrangement located on each end of a hub to form a closed air system in the interior of the hub or in combination with a second hub. The closed air system fluidly coupled to a pressurized air tank for receiving pressurized air. A pressure gauge provides a visual indication of the air pressure in the closed air system whereby a breached seal condition within the hub can be detected.