How to Fix a Moen Single-Handle Faucet Leak
- 1). Locate the hot and cold shutoff valves and turn both handles to the "off" position. These valves are usually located inside the sink cabinet against the wall. If there are no sink shutoff valves installed, turn off the main water supply shutoff valve; this valve is situated beside the water meter connected to main water supply line where it comes into the house.
- 2). Open the faucet to relieve water pressure still remaining in the pipes. Insert the tip of a flat-head screwdriver under the round cap on top of the faucet; twist the screwdriver to pop the cap off. Undo the retaining screw below the cap with the screwdriver. Place the cap and screw in a secure location where you won't lose them or flush them down the drain.
- 3). Grasp the base of the faucet handle and remove it by bending it backward while lifting and twisting slightly at the same time.
- 4). Wrap a rag around the round, knurled brass retaining nut on top of the rotating spout. Grip the nut through the rag with a pair of channel pliers. Twist the pliers counter-clockwise to loosen the nut and remove it by hand.
- 5). Hold the barrel of the spout and work it upward while twisting from side to side to remove it. This will reveal two rubber O-rings in the faucet body and the end of a forward facing U-shaped retainer clip on top of the housing holding the cartridge in place. Pry the two O-rings out of their grooves with the tip of the screwdriver and slide them off the faucet body with your fingers.
- 6). Examine the inside of the spout barrel. If it is caked with hard water deposits, soak it in white vinegar for 30 minutes to dissolve the deposits while you disassemble the faucet.
- 7). Put the tip of your screwdriver behind the U-shaped retainer clip from the top. Twist the screwdriver to loosen the clip, and pull it forward and out of its slot with your fingers.
- 8). Pay careful attention to the direction that the flat machined cut-out on top of the cartridge shaft is facing; you must insert the new cartridge the same way for it to work properly.
- 9). Position the white plastic cap that came with the new cartridge kit over the top of the cartridge shaft protruding from the faucet body. Place an adjustable wrench on the square nut molded to the top of the plastic cap. Press the top of the square nut down firmly with your thumb while working the adjustable wrench from side to side to loosen the cartridge.
- 10
Grip the top of the cartridge shaft between the jaws of a downward-facing pair of locking pliers. Clamp the pliers onto the shaft and grip the handle firmly with both hands. Pull the cartridge upward while twisting the pliers from side to side to remove it. - 11
Lubricate the barrel and seals of the new cartridge with a thin layer of heat-proof plumber's grease. Position the flat machined cutout on top of the cartridge shaft facing the same way as the old cartridge was facing. Line up the two lugs or "ears" protruding from the top of the cartridge barrel with the open retaining ring slot in the faucet housing and insert the cartridge all the way down into the housing. - 12
Insert the U-shaped retaining clip through the slot in the faucet housing straddling the front-facing ear on the top of the cartridge and push it home with your finger. Sometimes the ears don't line up perfectly; if this is the case, wiggle the retaining clip gently from side to side to line up the ears before sliding the clip home. - 13
Clean all hard water deposits from the section of the faucet housing between the two O-ring grooves that were exposed after removing the spout. Soak a rag in white vinegar and wrap it around the housing. Leave the rag in place for 30 minutes to soften the hard water deposits, then clean the housing thoroughly with fine steel wool and a rag. - 14
Lubricate the new spout O-rings with plumber's grease and slip them over the housing and into their grooves. Clean the softened hard water deposits from the inside of the spout barrel with a rag and fine steel wool. Lubricate the inside of the barrel and both O-rings with a liberal amount of plumber's grease, and lower the barrel over the two O-rings; wiggle the spout back and forth until it slips down all the way. - 15
Replace the round, knurled brass spout retaining nut, screw it down finger tight, then snug it down gently with the channel pliers. Move the spout from side to side to see that it moves freely without binding against the retaining nut. Replace the spout retaining screw and tighten firmly with the screwdriver before clipping the faucet cap back into place. - 16
Twist the faucet shutoff valves back to the "open" position, or reset the main shutoff valve, whichever is applicable. Lift the handle to open the faucet and move the spout from side to side while checking for leaks. Turn the faucet handle from left to right in the open position with your hand under the spout to see that both hot and cold water temperature controls are working correctly.
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