Hearing weird Brake Noises ?

When you have to suddenly stop your vehicle, nothing matters more than reliable brakes.  But when you hear noise coming from your brake system, does that mean there is something wrong?  Usually, but not necessarily.  

The following noises can be normal and are considered general characteristics of all braking systems:

This noise is common with rear-brake drums and on some disc brakes during the first few stops (such as after the vehicle has been parked overnight).  This is primarily due to the formation of trace corrosion (light rust) on the metal surfaces during vehicle non-use or storage.  This light corrosion is typically cleared from the metal surfaces after a few stops, thus causing the noise to subside.

This typically occurs intermittently with front-brake linings at medium speeds when you apply light-to-medium pressure on the brake pedal.  It may also occasionally occur on the rear brakes during the first few stops and/or with cold brakes (especially in the morning) and/or in high humidity conditions.

On automatic transmission vehicles, a slight groan may be heard when you come to an abrupt stop or when you allow the vehicle to creep forward slowly with the brakes slightly applied.

This noise will occur when the vehicle is first started and moved at low speed (for instance, backing or pulling forward out of a parking space).  A slight pulsation at the brake pedal may also be felt during the ABS self-test procedure.  If any problem is found during the self-check, the ABS system will deactivate automatically and the yellow "Anti-Lock" brake warning light on the instrument panel will light up.  If the warning light comes on, the vehicle should be taken to a qualified service technician for immediate service.  While the ABS system is deactivated (when the warning light is on), the brake system will operate as a conventional, non-ABS system.

While the above noises don't indicate improper operation or malfunction in the brake system, all unusual noises should be checked out by a service technician before too much time passes by.  If you let it go too long, you can be jeopardizing your safety, and adding unnecessary costs for additional brake repairs.