f73a157e_ion_and_Trouble_Shooting_Guide__PROBLEM
[CAUSE] -O ring not sealed properly. [SOLUTION] - If O-ring is damaged, replace. If dirty, clean, lubricate with Dow 111 silicone sealant and retighten filter housing sump. Hand tighten firmly. Do not use a filter housing wrench to tighten. [PROBLEM] 
Filter housing sump leaks.
Water Filter and Reverse Osmosis Installation and Trouble Shooting Guide
PROBLEM