A pressure compensation cap, system, and method for equalizing pressure in an endoscope while preventing a liquid from entering an interior of the endoscope through an opening. The cap is adapted to fit over an opening in the endoscope and includes a hole occluded by a filter. The filter is made with a material which allows certain gasses to pass through the cap into or out of the endoscope while preventing certain liquids from passing through at certain pressures and temperatures. The liquids, gasses, pressures, and temperatures may include those typically encountered when sterilizing an endoscope, those typically encountered during transport of an endoscope by air or otherwise, or those encountered at any time during the lifecycle of an endoscope.
