Dealing with Brake Noise Problems
Car manufacturers realize how important the braking system is for customer safety and satisfaction. Therefore these systems are some of the most reliable on the entire car. Redundant backups are in place such as the emergency brake and reserve braking which provides power assist even after the engine stalls. Auto makers also install warning devices to notify the driver regular maintenance is required. With that said even the most sophisticated braking system might experience unexpected problems drivers will have to deal with. Let’s discuss several of the noisy ones right here.
If you ask a professional mechanic what the number one complaint is from their customers, most will say brake noise complaints are at the top of the list. This is for good reason since noises are often the first indication of worn out parts or more serious problems within the system.
Different types of noises including rattles, grinding, excessive squealing and even clicking sounds when the brake pedal is pushed, fall under the category of noises the brakes shouldn’t be making. A road test by a professional and careful visual inspection is necessary because axle bearings, tires and wheels can produce noises that are often mistaken for brake malfunctions.
When diagnosing a grinding noise the most important piece of information is when the sound occurs. If it happens all the time and doesn’t change when the brakes are applied, mechanics will look in the area of wheel bearings or perform visual inspections to make sure a stone isn’t lodged between the mounting hardware and the brake rotor.
If the grinding changes intensity as the brakes are applied and released then a full brake inspection must be performed. It is common to find completely worn out brake pads or shoes in this type of situation. When the friction linings have worn out and the backing plate or rivets contact the rotor a violent and loud grinding sound will be heard. At night sparks can be observed from this metal on metal condition.
A clicking sound is another complaint that can be quite irritating when it happens with every application of the brake pedal. With this complaint it’s common to find loose or missing mounting hardware. The hardware is responsible for keeping the friction pads firmly in place.
Most models use steel spring clips to apply constant pressure to the pad. It’s not unusual to find these rusted and weekend after long periods of service. New clips or retainers come with quality replacement parts and should always be utilized if supplied. Cheap pads or lazy mechanics are just two reasons these may not be replaced during service.
More commonly drivers complain about squealing type noises. Because of their high pitch they are easily heard while driving. Individual diagnosis is necessary but we’ll talk about a few of the common problems and solutions for brake squeal. The sound itself is generated from high speed vibration or movement of the brake pad. One method to reduce this problem is the use of anti rattle clips that apply spring-loaded pressure to the inside and outside pads.
These absorb any movement while still allowing the pad float free. Another method is to apply sound deadening material to the backing plate itself. Some manufacturers include a carbon fiber type factory mounted. Bargain basement cheap pads will sometimes exclude this to reduce manufacturing costs. Disc brake quiet is an inexpensive silicone type material that can be applied to the backside of these low quality pads to reduce squeaks and squeals generated by pad movement. The use of this product is not recommended as it’s longevity is questionable.
Brake Wear Indicators
Some high end luxury cars have a fancy brake wear indicator that illuminates a warning light on the dash that says something like “check brake pads”. The more common type of wear indicator found on domestic cars in the United States would be a simple metal tab that is mounted to the backing plate. This metal tab is designed to rub against the surface of the rotor when the friction linings have worn down to their minimum thickness. The noise it makes is high pitched and can disappear if the brakes are applied firmly and then reappear as the vehicle coasts down the road.
With the importance of an automotive braking system any kind of unusual noises should be investigated immediately. Grinding and squealing noises could indicate that the friction linings have worn out and a standard brake job needs to be performed. A squealing sound that appears after a brake job could indicate the installation of inexpensive replacement parts or short cuts taken by the mechanic.
Drivers that experience noise after service should return to the shop that did the work as soon as possible. Push for a road test with the mechanic that performed the repairs to point out the specific noise. Often if an inspection is required the service center will perform these at little or no cost for paying customers.