Automobile brakes serve one basic but very important function: They stop the vehicle. Experiencing a failing brake system while you're driving demands quick thinking and skilled maneuvering - not to mention nerves of steel - to bring the car to a safe stop. If your car needs as much space to stop as a commercial airliner, it's obviously time to have the brakes inspected. Fortunately, the brake system usually warns you that something is wrong well before this happens.
Brake system basics
All parts of a car's brake system work together to stop the car safely, and if one part isn't working the way it should, the entire system ceases to operate properly. With disc brake systems, stepping on the brake pedal puts the system in motion by activating the master cylinder, which delivers brake fluid through the brake lines to the calipers. The fluid pushes on the pistons in the calipers, which squeeze the brake pads against the rotors and slow the car down.
Drum brakes operate like disc brakes, except that pushing the brake pedal forces brake fluid into the wheel cylinder. In turn, the wheel cylinder moves the brake shoes into contact with the inside of the drum, which slows the car. When you release the brakes, the return spring releases the shoes and pulls them back into their resting position, allowing the car to move.
Signs of a brake problem
One basic way of checking for impending brake trouble is to estimate the remaining thickness of the brake pads. You can peek in through the top of the brake caliper with the wheel off, and most dealerships and mechanic shops will do a brake inspection during routine service. Take your car in for service when the brake pads are less than 1/4 inch thick; otherwise, you'll soon hear metal rubbing on metal as you apply the brakes. According to the Federal Trade Commission, there are other obvious signs of a brake problem in the making, and you can detect most of them by using your senses.
Brake warning light: Even if you don't smell or hear anything that tells you something's wrong with your brakes, the brake warning light on your dashboard is an indication of a problem. If you see this light, take your car in to be checked out. Never ignore the brake warning light.
Fluid leak: You can check your brake fluid simply by looking at the brake fluid reservoir. If the fluid level is below the "full" line, add more fluid until it reaches the line. But unlike oil, losing a little bit of brake fluid could be a sign of a bigger problem. A damaged brake line may leak fluid. When this happens, the fluid level in your brake fluid reservoir falls and you may notice a puddle of oily fluid on the pavement around the tire area of your car. Stepping on the brake pedal pushes more fluid through the lines that will continue to leak onto the pavement. The pedal may have a spongy feel or it may go all the way to the floor with little or no resistance. If there's no brake fluid, the brakes won't work, which leads to a dangerous situation if the vehicle is in motion. Do not operate the car without fixing the leak.
Abnormal sounds: Hearing a grinding or squealing noise when you apply the brakes is a good indicator of worn pads or shoes that require replacement. If you don't have the problem fixed, the sound will get worse over time. Disregarding these types of noises can lead to rotor damage and more expensive repairs down the road.
Shaky steering wheel: A steering wheel that shakes when you apply the brakes is a symptom of possible rotor problems. It most likely suggests that the rotor is warped and the pads don't make even contact as the brake disc spins. If you neglect this symptom now, you're asking for more expensive repairs and replacement parts later.
Burning smell: A burning smell when you're braking or light smoke coming from the tires means there's a possibility of stuck brake pads. Check to make sure you don't have the emergency brake engaged and, if so, release it. If that doesn't work, your car could have other potential problems that call for maintenance.
Pulling: Feeling your car pulling to one side or the other when you brake is a sign of several potential problems. It could be a bad steering alignment, but symptom could also mean leaking fluid or a frozen or worn-out brake in one corner. All these situations signal the need for repairs before they lead to other more serious problems.
Spongy pedal: If you put your foot on the brake pedal and it feels spongy or you have to push it down farther than normal, there could be a couple of problems going on with the system. This symptom is generally indicative of air trapped in the brake system, and the solution might be as simple as bleeding the brakes to release it. It could also mean you have a leak in the brake line. In either case, maintenance is essential as these problems affect your braking ability.
Acceleration drag: A sensation of drag on the car when you're accelerating means you may have a stuck emergency brake. An emergency brake that's frozen continues applying pressure to stop the car, even if it appears to be disengaged. This usually happens because of rust and requires inspection before additional damage occurs.
Basic brake maintenance
The appropriate interval for regular brake inspections depends on your car's make and model and the recommendations found in your car owners manual. If you prefer to err on the side of safety, take your car in for a yearly brake inspection to ward off potential problems. Keep in mind that scheduling regular inspections and nipping any problems in the bud can help prevent expensive repairs. Since the brake system is so important when it comes to safety, don't ignore any signs of possible trouble. Instead, have them quickly checked out by a certified mechanic.