What is an O-Ring?

An o-ring is the thin rubber ring that is usually at the top of a housing. It looks like a tiny hula hoop. It is used to seal the cap (top) and the sump (bottom half) of the housing. O-rings are sometimes referred to as gaskets.

What is a gasket?

A gasket is a thin rubber piece that is often part of a filter cartridge. A gasket looks like a frisbee with a hole in it. Gaskets help the cartridge seal to the housing. Gaskets are sometimes referred to as o-rings.

Do I need a new O-Ring?

Some people like to change O-Rings every time they change their filters to ensure that there will not be a leak. Others change their O-Rings only after changing the filter several times.

Should I use a lubricant on my O-Ring?

If you choose to reuse your o-rings, you should use a lubricant on them to keep them effective. You can use a special silicone lubricant such as this O-Ring Silicone Grease.

First, wipe your old O-Ring clean. Then wipe the groove in the filter housing clean. Finally, apply just enough lubricant on the O-Ring to give it a gloss.

Do I need to lubricate the gasket on the filter cartridge?

Generally, no because each replacement filter cartridge comes with its own new gasket.