Method and arrangement for pre-cleaning an endoscope

A method for pre-cleaning an endoscope, the method comprising:

• connecting a liquid source, a suction pump, and a sealing element each to a different one of a first channel opening, a second channel opening, and a third channel opening of respective, first, second and third channels of an endoscope connected to each other at a channel connection, the connecting being such that each of the first, second, and third channel openings are connected to either the liquid source, the suction pump, or the sealing element, wherein the first channel opening is arranged at an end of the first channel section and at a distal end of the endoscope, the second channel opening is arranged at an end of the second channel section and formed as a connection port, and the third channel opening is arranged at an end of the third channel section and formed as a connection port;
• wherein the liquid source is configured to provide a gas-tight sealing from the environment that surrounds the liquid source, the liquid source has a holding chamber with a holding chamber volume for holding the liquid, wherein the holding chamber volume of the holding chamber is changeable;
• and
• activating the suction pump for drawing liquid from the liquid source towards the suction pump, wherein the holding chamber volume of the liquid source reduces during drawing of liquid from the liquid source.