John Linden: Hi! I am John Linden; Master ASE Certified Technician and North America Training Manager for Midas International Corporation. Today, I would like to talk to you about how to diagnose some common brake problems. If the amber colored anti-lock brake light or the red brake warning indicator light is on, this should be checked by a mechanic as soon as possible; preferably one who is ASE certified in brake repair. If the red warning light is on constantly, it generally means that you have a hydraulic or brake fluid problem in the brake system. This could be dangerous and should be checked as soon as possible.
Some vehicles use the red warning light to alert you that the parking brake is on. If the red warning light is on, put your foot under the parking brake pedal, and as you pull out on the release handle, lift up the parking brake pedal with your foot. If the red brake light goes out, you most likely have a parking brake issue. The red brake warning light can also be used to alert the driver that the brake fluid level is getting low. Brake fluid under normal condition should never be low. The brake system is a hydraulically sealed system that you should not have to add fluid unless there is a leak.
Low fluid could be a sign that the brake pads or brake shoes are getting low. A brake noise could be a number of things. But, if you hear a grinding noise, it generally means that the brake pads or brake shoes no longer have any friction material left and you are stopping on metal to metal, which has a direct effect on how well the vehicle will stop. If you feel the brake pedal pulsating or going up and down as you apply it, a brake rotor or brake drum could have what is called excessive run out. It is similar to a bicycle with the bent rim, in that it wobbles when it rotates.
If you feel the brake pedal going up and down rapidly doing a hard or emergency stop, this maybe normal. If your vehicle is equipped with anti-lock brakes, the ABS unit pulsates the brakes electronically, preventing the wheels from locking up.
If your car pulls to one side when braking, it usually indicates a hydraulic problem with the brakes. If a disc brake caliper oil wheel cylinder ceases up, it will cause the brakes to pull to the opposite side. If you hear a squeal noise while applying the brakes, this could indicate that the brake pads or brake shoes are loose or vibrating.
Now, if you hear a squealing noise with your foot off the brake pedal, this could be a squeal sensor making noise. Numerous vehicles are equipped with a squeal sensor. That alerts the driver that the brake pads are getting low and should be checked as soon as possible. Doing so could save you time and money. The front and rear brakes work in conjunction. So anytime you have your brakes checked, have all four wheels inspected. The mechanic should show you and explain why the part or parts wore out or failed. If this explanation does not sound right, get a second opinion.