My older W203 C180 Kompressor makes a really annoying high pitch noise when braking...screeching you can say.

Change of brakes needed ? Or something else?

 

Lots of causes will cause a screeching sound when your car brakes. One would be that it's running low on brake pads. Check to make sure if the brake pad wear is below the indicator line. This "indicator" is made of metal, and when your brake pads are worn out, it will get in contact with this metal indicator, causing the screeching sound.

Less serious causes may be just debris or surface elements rubbing between your brake pads and your calipers. Take it to a mechanic shop so they can find the rue cause for you.