Quick-Connect Coupling With ID Marking
WARNING: This page is about a different car, the 2010 BMW 135i, 2009 BMW 135i, and 2008 BMW 135i. However, it is still accessible from the selected car via links, so may be relevant.
Removing:
Push quick-connect coupling (1) against pipe (4) (thereby relieving strain on spring (2)).
Press plastic ring (3) into quick-connect coupling (1) and remove coupling (1).
Assembly:
Markings (K) on coupling (1) and pipe (4) must be flush.
Push quick-connect coupling (1) onto pipe (4) until a "click" can clearly be heard.
To check that quick-connect coupling (1) has been installed correctly, pull it back forcefully.