How to Replace a Moen Stanadyne Cartridge

How to Replace a Moen Stanadyne Cartridge. If your Moen Stanadyne faucet suffers from leaks or poor water temperature control, replacing the cartridge is the best method of repair. It takes about a half an hour or less to complete, if you are experienced with plumbing fixtures and home appliances, or up to an hour if this is your first time working with appliances like this. You will find replacement cartridges at plumbing supply outlets and hardware stores. After the repair, your faucet should run like new again.

Things Needed

  • Allen wrench or screwdriver
  • Small pry bar
  • Large pliers or adjustable wrench

Step 1

Turn both water valves underneath the sink counterclockwise to close them.

Step 2

Find the small set screw on the faucet handle. The set screw, which holds the handle to the stem of the cartridge valve, will be located at the base of the handle or under a round cap on top of the handle. Take off the cap first, if your faucet has one. Insert a screwdriver if the screw has a regular head, or an Allen wrench if it has a hexagonal head, and turn counterclockwise to remove.

Step 3

Lift the handle off the base. If the handle does not budge, slide a small pry bar under the base of the handle and gently pry it off the faucet.

Step 4

Unscrew the dome cap or bonnet, a round nut right under the handle, with a pair of pliers or an adjustable wrench and remove it by turning it counterclockwise. Then remove the retaining nut, another small round nut securing the valve to the faucet body, with a pair of pliers or the wrench. Turn this retaining nut counterclockwise to remove it.

Step 5

Grasp the end of the cartridge valve, which is called the stem, and lift it straight up and out of the faucet. If the cartridge valve does not budge, place a Stanadyne cartridge puller over the stem. Turn it right to tighten the puller and secure it to the cartridge, and then pull the cartridge valve free by turning it the opposite direction. Always follow the cartridge puller directions for appropriate use.