Removal & Installation of Quick-Release Coupling with ID Marking

Push quick-release coupling (1) against pipe (4) thereby relieving strain on spring (2). Press plastic ring (3) into quick-release coupling (1) and remove coupling (1). See Fig 1.
To install, markings (K) on coupling and pipe (4) must be flush. Push quick-release coupling (1) onto pipe (4) until a "click" can be heard. To check that quick-release coupling has been installed correctly, pull it back forcefully.

Fig 1: Identifying Quick Release Coupling With ID Marking

Courtesy of BMW OF NORTH AMERICA, INC.