Did you flush out the valve body prior to installing the new cartridge
To remove a Moen bathroom faucet cartridge, first turn off the water supply. Then, use a cartridge puller tool or pliers to grip and pull out the cartridge from the faucet body. Be sure to follow the manufacturer's instructions for your specific faucet model.
To remove a Moen faucet cartridge, first turn off the water supply. Then, use a cartridge removal tool or pliers to grip the cartridge and twist it counterclockwise to loosen and remove it from the faucet body. Be sure to follow the manufacturer's instructions and use caution to avoid damaging the cartridge or faucet.
Any faucet or control that mixes the hot and cold water before it comes out of the spout is a mixer valve. It is usually reserved for a shower control. They will vary in how to fix them. Some you replace rubber seals and gaskets, some you replace a cartridge. It is really no different than a kitchen faucet in the way it is put together. All of them you take the handle or handles off, then the trim plate and then you have access to the valve. Some are screwed in and some are held in with a clip that locks the cartridge in the body of the control. With the water turned off, taking it apart one step and layer at a time, laying out the pieces as they come off, it shouldn't be a problem fixing it. I believe this is true, if the valve screws in, it will probably have rubber seals that can be replaced. If the cartridge is held in with a clip, you replace the entire cartridge.
To remove the cartridge from a Moen shower faucet, first turn off the water supply to the faucet. Next, remove the handle and any other components covering the cartridge. Use a cartridge puller tool to carefully extract the cartridge from the faucet body. Be sure to follow the manufacturer's instructions and use caution to avoid damaging the faucet.
The inside part of a Moen faucet / shower body
To remove a cartridge from a faucet, first turn off the water supply. Then, locate the set screw or retaining clip on the handle and remove it. Next, use a cartridge puller tool to carefully extract the cartridge from the faucet body. Be sure to note the orientation of the cartridge before removing it for easier reinstallation.
To remove a Moen cartridge from a faucet, you typically need to locate and unscrew the retaining nut holding the cartridge in place. Once the nut is removed, you can use a cartridge puller tool or pliers to carefully extract the cartridge from the faucet body. Be sure to follow the manufacturer's instructions and use caution to avoid damaging the faucet during the removal process.
To remove a Moen kitchen faucet cartridge for replacement or repair, first turn off the water supply to the faucet. Then, use a wrench to loosen and remove the retaining nut that holds the cartridge in place. Once the nut is removed, you can pull out the cartridge from the faucet body. Be sure to note the orientation of the cartridge before removing it so you can install the new one correctly.
To remove a Moen shower valve cartridge, first turn off the water supply to the shower. Then, use a cartridge puller tool to grip the cartridge and pull it out of the valve body. Be sure to follow the manufacturer's instructions carefully to avoid damaging the valve.
To remove a shower cartridge, first turn off the water supply to the shower. Then, use a cartridge removal tool or pliers to carefully twist and pull out the cartridge from the valve body. Be sure to follow the manufacturer's instructions for your specific shower model to avoid damaging the cartridge or the valve.
I assume the handles are the quarter turn type. If you turn the into the bowl to shut them off, it may be that the handles are just set on the stems wrong. If this is not the case, the cartridge in each side is in backwards. Shut the water off, take the handle off and the ring under the handle that holds the cartridge in. Pull straight up on the stem, pulling the cartridge out and rotate the whole cartridge 180 degrees and reinstall. There should be two small notches in the body of the faucet that line up with bumps on the cartridge.