If brakes on a vehicle make any type of noise under driving and braking conditions, it is the sign of a malfunction. Noises may be a variety of brake and brake mounting systems failures, or they may be other problems that occur when the motion of braking creates movement in another part. This can include steering parts, motor mounts and transmission mounts.
Brakes may make a scraping sound at low speeds, which can start quietly in a rhythm coinciding with the speed of the car and gradually become much louder. The scraping rhythm will increase in speed as the car speeds up and then becomes inaudible at higher speeds. This can be a sign of brake shoes or pads that are entirely worn down to the metal, and in this case, the brakes may not stop your car when it involves metal-to-metal braking. Check pads and shoes for wear and replace them if necessary. Wheel bearings that are loose or have failed will also cause this sound; they'll need repacking or replacement. A scraping sound can be a sign that the mounting hardware for disc brakes needs adjustments or replacing. Adjustments will hold the disc pads in place so they do not move and cause the scraping sound.
A clunking or banging noise may be audible when applying brakes on a car. Harder braking creates a louder noise at higher speeds. This can be a failure of steering parts like the rack-and-pinion steering on a front-wheel-drive vehicle or tie rod ends on a rear-wheel-drive vehicle. The steering parts can be cracked or broken and need replacement before they are inoperable.
Shocks and springs can cause a clunking noise when braking if they are loose or broken. At times, these suspension parts can benefit from an adjustment or they may need replacing. Calipers that hold the disc brake pads in place may be out of adjustment, which will cause clunking. Adjusting or replacing calipers is advisable if this is the case. Broken motor and transmission mounts also make a loud clunking noise when the brakes are in use just before or after the vehicle stops its forward motion.
Squealing noises when applying brakes may point to mud, dirt or brake dust on the pads or shoes that cleaning and sanding will fix. Brake pads and shoes may be wearing out due to usage and need replacement or they may have excessive heating problems, which can be attributed to a lack of brake fluid. In overheating cases, a vehicle may pull to one side or the evidence of steam and smoke may appear around that tire. Brake pads and shoes can also have a squealing noise that is in their make-up by the manufacturers. This audible sound is a signal to replace brakes before they become dangerous and cause accidents.