A method detects proper connection of a test connection to an endoscope port which leads to an interior space beneath a flexible sheath on an endoscope. Both the interior space and an air buffer are pressurized and then isolated from each other. Pressure in the interior space is vented and the isolation is removed. After the pressure settles out the new pressure is compared with the first pressure. If it has not dropped substantially it is determined that the test connection is not properly attached and the interior space is in fact not being pressurized.
