Actually, it could take you longer to find the right part than it does to make the repair. Most major faucet manufacturers make single-lever faucets, and replacement parts are widely available at home center and hardware stores, but the valve assemblies are not interchangeable. Even different faucet models from the same manufacturer are likely to require different valve replacement parts. It will be easier to get the right parts if you know the name of the manufacturer and the faucet model number. If you know the manufacturer but not the model, a local plumbing-supply house might be able to narrow the choices for you. If all else fails, pull the old part before buying a new one. That's not the most convenient option, Sorrell says, but at least it's foolproof.
We used a Moen faucet for the steps shown here. If your faucet is from a different manufacturer, the parts will look a little different. But, according to Sorrell, the procedure for replacing them is virtually the same. Cartridges are available in both plastic and brass; plastic cartridges work just as well as their brass counterparts, and they are a few dollars cheaper. If you have well water, Sorrell suggests the plastic model because it is less susceptible to damage from untreated water.