No matter how complicated a faucet seems, you can repair most faucets by following a few simple steps that apply to most faucets. First remove cap and the screw that holds the handle on. Secondly, remove the retainer which is usually present in some form on most faucets that secures the valve parts inside the faucet body. Then there should be some trim pieces and some kind of sealing device-springs, O-rings or button seals that regulate water flow. The illustrations above will show you an idea of how different faucets are set up and their similarities.
The Moen cartridge faucet system has evolved substantially over the years. Early designs lasted a long time. Their design is uncomplicated, they repair easily, and parts are available and inexpensive. The newer Moen design uses more parts and is far more complicated to take apart and put back together. Even still, these faucets are not difficult to repair.
Follow the steps outlined below for instructions on how to repair.