: How do I know when to replace a cartridge and when to get out the silicon grease? I have five faucets (2 showers & 3 lavatories) that are very hard to operate in and out. All use the 1225 cartridge. I replaced one about five years ago, the others are 19 years old. Water supply is hard. How does one clean the interior of the faucet body

Pete,
19 years is a long time. You can pull the cartidges to clean and grease them, add new seals. Or while you are at it, just pop in new ones. You will need to balance effort with cost. The new ones will outlast the tuneups.