If you are experiencing water leaking between the reservoir and the base, replacing the O-ring & seal will correct this issue.
As you can see the O-Ring is installed on the bottom of the reservoir. Use a pointed object like a pin to remove the original O-ring. The new O-Ring will install easily.
Please note that the Gasket installs with the 3 spokes facing downward.
The Gasket is installed from the top with the 3 spokes facing downward.