When considering car safety features, brakes should be at or near the top of the list. After all, stopping in time is the most frequent safety activity performed by a vehicle. Brakes use the principles of mechanical advantage (leverage) and hydraulics (force multiplication).
Fortunately you don’t need to know a thing about physics to keep your brakes in top shape. What’s important to know is that brakes include many serviceable components such as pads, shoes, rotors, drums and fluid.
Disc brakes traditionally on the front wheels, squeeze a pair of pads against a rotor that turns with the wheel to slow the wheel down. When pressure is released, a piston seal pulls the pads back to allow wheel rotation.
Drum brakes, may be used in the rear on some cars. Drum brakes use shoes in a rotating drum that are forced outward to provide friction to slow the wheel.
Over time, friction wears down braking components and they need to be replaced. Quality of materials is important. Less expensive brake components could be less safe and wear quickly or produce unwanted noise. Cheap rotors may not properly remove heat.
What’s the difference?
Less expensive rotors may only last about 10,000 miles. Manufacturers make them faster and cheaper by reducing heat treating procedures and cool down time.
Higher quality rotors, lasting 25-40,000 miles, are heat-treated and have more mass so the heating process can create the correct hardness, resulting in better stopping power and a longer life.
First You Hear It
Drivers recognize they need new brakes when brakes squeal or squeak when applied. It might take more force to apply the brake pedal or the pedal depresses closer to the floor, before the vehicle stops. If the vehicle pulls strongly to right or left instead of stopping in a straight line, brakes should be checked.
Ceramic vs. Metal
Ceramic brake pads improve grip and are more reliable and quieter than metallic. They don’t create annoying brake dust on affected wheels and extend rotor life. But they wear out quicker and cost more.
Metallic brakes wear out brake pads and rotors faster. They create more heat when stopping and over time this decreases the fluid’s effectiveness, making synthetic brake fluid a better choice for metallic brake pads.
Brake fluid should be changed every two years or according to your vehicle manufacturer’s recommendations because it absorbs moisture, and that can cause brake fade or failure.
Braking Tips
Drivers should practice using anti-lock brakes to experience the kick-back on the brake pedal and know what to expect. The key is to hold your foot firmly down. The kick-back is the computer re-adjusting brakes in milliseconds to provide maximum braking power and control. The anti-lock brake warning light may trigger when a spare tire is used due to the difference in wheel speed compared to the other wheels
Jim Grey is president of AAA Car Care Center and a master technician. For more car care tips and money-saving coupons, visit AAA.com/carcare. |