Many many things about tune up
There's a good chance that you have a leak in your brake fluid line. Brake wear indicators are supposed to wear down, if you think about it; if they did not, they would not be performing their job well. They're meant to grind and also squeal upon release of the brake pedal when it's time for brake repair. However, other rotor issues may be present if a brake pedal or wheel begins to vibrate. Have your brakes checked out as soon as possible! Experts suggest a few preventative measures to keep your brakes functioning properly.