Replacing the o-ring
Protecting the inner side of the camera sleeve from dust
The o-ring is located beyond the sleeve of the camera and serves for sealing up the inner side from pollution. From time to time we should check and replace it, when it's damaged or lost (like in our case. The oder number for new ones is 6680974 Sealing Ring 26x1. Remove at first the sleeve. Replace a new o-ring in siding it to one point of the o-ring groove, then use your thumb and your index finger to push the ring into the groove.
DR. ANDREAS KURBAD