If new pads came with your new calipers, they can squeal a bit until they 'run in'. If you didn't replace your rotors or have them re-surfaced, they can quickly destroy your new pads causing metal-to-metal grinding.
There are a lot of reasons. And of them is you have to change brakes pads. Of course it can be something else but the car is too new to have major problems with it. PS: If you have "sticky" brakes you need to check brakes calipers as soon as possible.
they are horny
The posts that the calipers slide on need to be lubed too. Look at the brakes, something is touching the rotors. Something has been put together wrong or the slides are binding and the pads are staying in contact with the rotors after the brakes are released.
The calipers or wheel cylinders are bad.
The calipers are stuck, or they are cheap brakes, or somebody got oil or grease on the brakes and disks.
usually it will to the brake pads wear a little or it could be your rotors
To replace your bike brakes, follow these steps: Remove the old brake pads and calipers. Install the new brake pads and calipers. Adjust the brake tension and alignment. Test the brakes to ensure they are working properly.
Disk brakes can be noisy. Sometimes you need to use a special compound that stops brake noise.
To replace bike brakes effectively, follow these steps: Remove the old brake pads and calipers. Install the new brake pads and calipers. Adjust the brake tension and alignment. Test the brakes to ensure they are working properly.
Your new bike disc brakes may be rubbing due to misalignment of the brake calipers, a bent rotor, or improper installation.
you need new brakes
Disc brakes are supposed to drag on the rotors, if you think they are too tight you will have to replace the calipers. The caliper slides may need cleaning and new hardware to allow the calipers to move freely.