Car Brakes for Dummies: 5 Things You Should Know
You don’t have to be a professional to understand a brake system. In fact, knowing a few things about how they work can help keep you safe. Here are a few things every driver should know about car brakes.
How Car Brakes Work
Hydraulics: When you step on the brakes, the brake pedal lever amplifies the force of your foot to compress the hydraulic system. Pressure builds in the master cylinder, which is transmitted to the brake calipers or wheel cylinders. The system is a closed system, that is, brake fluid doesn’t enter or leave. If you notice low-fluid level, but not below the “low” mark, do not top it off, but inspect your brake pads and shoes for wear. If the fluid goes below the low mark, you may have a brake-fluid leak, which should be checked and repaired immediately.
Boosting: Your foot pressure alone is not enough to stop your car safely, which is why it’s boosted, often vacuum boosted. Some older cars used hydraulic boosting, taking pressure from the power steering pump, while newer cars use an electronic booster. All three systems multiply the force you can put into the brakes, making it easier for you to stop your car safely. Keep in mind, even if you’ve heard it will save gas, don’t turn off your car to coast down that long hill. Downshift instead.
Anti-Lock Brakes: When you’re learning to drive in the rain and snow, you’re often told to pump the brakes to keep the car from going into a skid — and this used to be true of older cars. Anti-lock braking systems (ABS), standard on most cars since the mid-1980s, have eliminated the need for pumping the brakes. Instead, the ABS module uses wheel-speed sensors look for a wheel locking up, using a high-seed solenoid valve to temporarily reduce pressure on that wheel. In this case the wheel doesn’t lock up and you can maintain control of your vehicle.
Noise: Generally speaking, you should not hear any noise when using the brakes on your car. If you hear any noises at all — squeaking, squealing, grinding, knocking, whining, groaning — have your brakes checked immediately. Keep in mind, emergency braking or hard braking on loose surfaces may engage the ABS system, which has an activation noise that has been described as grinding, buzzing or groaning.
Vibration: When you step on the brake pedal, you should feel constant pressure feedback from the system. If you feel pulsation in your foot or vibration in the vehicle or steering wheel, you may have a rotor or drum problem, sometimes caused by overheating. If you feel a vibration, have your brake system checked. Note, though, that ABS activation is often accompanied by pedal vibration, which is normal.
Knowing the basics of how your car brakes work leaves you more informed during your next visit to the mechanic. Be observant and you’ll catch brake problems before they become unsafe or cause any collateral damage.
Check out all the brake system parts available on NAPA Online or trust one of our 16,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on your car brakes, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photo courtesy of Wikimedia Commons.