Grease the O-ring
If the O-ring is not properly greased, it may crack or peel, causing leaks. If the bottom of the O-ring appears dry, place a drop of O-ring grease on your index finger and spread grease on the O-ring by sliding it between your thumb and index finger, gently stretching the ring. Do not use cloth or paper, as these may leave fibers on the O-ring. Note that applying too much grease may cause foreign matter to adhere more readily to the ring, preventing the case from sealing properly.
Replace the O-ring
Making sure the O-ring and guide are free of foreign objects, place the O-ring so that it runs evenly at the same level all the way round the O- ring guide, without undue stretching and without protruding from the guide.
Check the seal
Close the case and check that the case is fully sealed. If the O-ring does not form a perfect seal, open the case and adjust the O-ring to prevent leaks.
Cleaning
18