If your car brakes making grinding sound when stopping, you need to fix it as soon as possible. One way to do this is while driving slowly near a wall or a row of parked cars, open your car windows. The sound will bounce off the wall or the parled cars and this can give you some idea whether the sound is from the front or rear wheels
Generally the front brakes wear first before the rear. However, it is important to have all 4 wheels checked whenever you hear noise related to braking. If you hear grinding sound, chances are the brake pad or brake shoe friction material has worn so thin that the metal rivets or steel backing plates are exposed directly to the brake rotors or drums.
The metal to metal contact between the brake pads and the rotors or between the brake shoes and the brake drums could damage the surface of the rotors or drums.
Mechanics could repair the slight damage by machining the rotor or drum surface on a brake lathe. This process also known as cutting cutting the rotors or drums whereby the old metal surface is cut away to create a new smooth surface.
Any way, there is a legal limit to how much metal can be removed. If the damage exceed the legal limit, you need to replace the rotors or drums with brand new.
Other way to solve this problem is by checking the red brake warning light on the car instrument panel. If there’s problem with the barke hydraulic system, the warning light will lit. The light will be ON when there is brake fluid loss. The indication also stays ON when the rear brakes are badly worn out.
Brake warning light accompanied with grinding noise might be caused by worn or misalligned rear brake shoes. Ask the mechanic to check the brake for wear and adjust or replace the brakes when required.
