Things You'll Need
The Moen 103258 faucet is a discontinued single-handle shower faucet. This faucet is an early version of the Chateau line before posi-temperature controls were added. Repairing or replacing the faucet requires taking it apart. Disassembling the Moen 103258 faucet is much like any other single-handle faucet. If you are disassembling to replace the cartridge, take the old cartridge to a home improvement store. Match the new cartridge to the old one to ensure that you get the proper size.
Locate and turn off the water supply to the shower. The shut-off valves are usually in the wall behind the faucet. There should be an access panel in the adjacent room that allows access to them. If you cannot find the shut-off valves, turn off the main water supply to the house.
Place a towel over the tub drain to prevent accidentally dropping screws down the drain. Find the screw securing the handle to the faucet. The screw is under the curve of the handle near the decorative escutcheon plate. Remove the screw with a Phillips-head screwdriver and pull the handle off the faucet stem.
Remove the screw securing the adapter to the faucet cartridge with a Phillips-head screwdriver. The adapter is the white plastic piece extending beyond the escutcheon plate. Pull the adapter away from the cartridge.
Unscrew the two retaining screws that secure the escutcheon plate to the wall with the Phillips-head screwdriver. Pull the escutcheon plate away from the wall. Pull the white plastic plate that sits behind the escutcheon out of the wall. This reveals the rest of the cartridge assembly.
Find the two c-clips that secure the cartridge to the house plumbing sleeve. The top of the c-clips are visible on the top front and back of the plumbing stop valve. The stop valve is the part of the house plumbing where all the shower pipes connect.
Pull the c-clips out of the cartridge with a pair of needle-nose pliers. Remove the cartridge from the stop valve with a pair of pliers. Grab the cartridge by the end and pull it straight out.
If the cartridge will not budge, purchase a Moen cartridge puller at a home improvement center. Moen manufactures a line of cartridge pullers specifically to remove their cartridges.