Checking the rotors, drums, discs, pads and shoes of the brake system is usually done for free at most brake specialty shops. Having the system checked every three to four months is a good safety idea plus it can help you stop and determine any possible problems that may be developing.
Most brake systems have a sensor that will start to make a squealing or squeaking sound when the brakes are wearing down. This squealing is usually heard when the vehicle is in motion but will stop when the brake is pressed. Always get the vehicle into be serviced when you hear this sound.
