Just got my upper left ball joint replaced Now when I brake it makes a screeching noise. It will only do it when I have the pedal down about half way and doesn't do it all the time What could it be
My car has 77000 miles.
My car has an automatic transmission.
You may have got a little grease on the inside of the rotor when work was done and this will cause the squeal from the brakes getting glazed. Try to go on a safe road where you can get up to about 45 and stop quickly a few times and see if problems goes away. If it does not, have the brake system inspected by a qualified technician, like one from YourMechanic, for glazed rotors and pads.