More than likely your brake pads are worn down to the backing plate and need to be replaced.
When rainwater gets on brake pads, it can cause them to vibrate and make a squeaking noise when the brakes are applied.
They are equipped with a "telltale" warning that shrieks when the brakes are applied, with the brake pads are too low and need replacing.
Inspect the brake pads. They are probably worn out and need replacing.
Probably scoured or warped rotors.
When there are any issues with your brakes it is best to take your car in to a certified mechanic. Brakes can knock for several reasons, including the calipers, brake pads, and bearings.
this is usually the indicator that you need new brakes so dont worry just get them replaced problem solved
When the brake pads are worn the rivets will actually touch the brake rotor when the brakes are applied. The brakes should be changed immediately.
Most times, the squeaking and rubbing noises are caused by brake pad wear, but you say the brakes are fine. Otherwise, if by constant rotation speed you mean the squeaking/rubbing noise is present even when the brakes are not applied, you might want to get the wheel bearing inspected
Brakes squeak when cold because the components of the brake system, such as the brake pads and rotors, are not yet warmed up and may not be making full contact. This can cause vibrations and noise when the brakes are applied, resulting in a squeaking sound.
sounds like you need pads cheap fix
depending on the year it might be a bad bearing, ball joint or spindle. have a mechanic check it out
only thing i know that will make brkes grind, is worn out brakesmaybe have em checked at a different mechanic