How to Fix a Moen 7800 Faucet From Leaking

Steve Smith

If you own a leaky Moen 7800 series faucet, you can fix it without changing the faucet. This repair also works on many other Moen kitchen faucets. However, a few steps are specific to the 7800 series. Making this repair takes about a half hour to complete and is a permanent solution to leaking or temperature problems. The cartridge in the faucet is worn, so this part needs replacing.

Step 1

Turn off the water to the faucet by shutting the water valves under the sink. Turn the valves all the way to the off position, or clockwise on most pipe valves, to shut them.

Step 2

Pull out the plug on the front side of the faucet with a pair of pliers and unscrew the set screw under the plug with an Allen wrench. Take off the handle by pulling it up and away from the faucet.

Step 3

Remove the handle dome -- the round nut under the handle -- by turning it counterclockwise with a pair of pliers or your hands, if possible. Unscrew the cartridge nut right under this part with a wrench.

Step 4

Remove the cartridge by picking it up and out of the faucet with your hands or a pair of pliers. Replace the cartridge with a new one designed for your 7800 series faucet.

Step 5

Replace the cartridge nut and tighten it with a wrench to secure the cartridge inside the faucet. Replace the handle dome and tighten it. Then replace the handle and tighten the set screw. Replace the plug by pushing it into the round screw hole.