A properly functioning brake system is not only critical to your own safety, but the safety of your passengers and other motorists on the road. Modern brake systems are highly complex systems designed to stop your several thousand pound vehicle quickly and efficiently. When you push the brake pedal it depresses a piston in the master cylinder, forcing fluid along the pipe. The fluid travels to slave cylinders at each wheel and fills them, forcing pistons out to apply the brakes. Fluid pressure distributes itself evenly around the system. The combined surface ‘pushing’ area of all the slave pistons is much greater than that of the piston in the master cylinder. Consequently, the master piston has to travel several inches to move the slave pistons the fraction of an inch it takes to apply the brakes. This arrangement allows great force to be exerted by the brakes, in the same way that a long-handled lever can easily lift a heavy object a short distance.
How do you know if you are in need of brake repair? Here are some symptoms you should be on the look out for.
Picture this: You’re out driving with the radio off and the windows rolled up. In the relative quiet, you hear a faint scraping, squealing, or buzzing sound. You also observe that, whenever you hit the brakes, that mysterious noise goes away, only to return again as soon as your foot comes off the brake pad. What’s going on here?
Today, most—but not all—brake pads are manufactured with built-in “wear indicators.” The sole purpose behind these things is to emit that unpleasant screech you just heard. Wear indicators are metal tabs located near the top of typical brake pads. When the pad itself wears down to a dangerous extent, the indicator will scrape against the rotor. This creates a distinctive grating noise which warns the driver that his or her current pads are in danger of eroding away altogether.
In some cars, the brake pads fit snugly into a special holding device. Other vehicles keep them steady with clips, bolts, or pins. At all rates, the common goal behind these designs is to keep the pads from wobbling around. If they become loosened somehow (perhaps after a part of the surrounding hardware gets damaged), they’ll begin to rattle. What then results is a clicking sound that rings out whenever the brake pedal is pushed or released.
This problem has a name and that name is “brake fade.” More often than not, it’s the direct result of intentionally applying the brakes over a vast distance without bringing the car to a full stop. From time to time, such a maneuver might be necessary, particularly when driving down a mountainside or over a winding road. However, if this is something you do frequently—say, if you live in a hilly area where you must regularly drive downhill—it will take a toll on your braking mechanism over time. By forcing the pads to make contact with the rotors for a long, uninterrupted period, both components will heat up. In the process, their ability to generate needed friction against each other is reduced over time. As a result, you’ll find that your car won’t come to a complete stop as rapidly as it once did.
Your vehicle’s brake pads won’t always wear out at the exact same rate. Sometimes, those on one side will get thinner faster than their counterparts on the other side. Should this occur, the car may pull slightly to the left or right once you hit the brakes. Leave the problem unchecked, and you’ll put unnecessary stress on your steering rack (plus your vehicle’s ball joints, steering knuckles, and wheel bearings). Don’t risk it: Have a mechanic investigate the problem immediately.
Note that brake pads might not necessarily be the cause behind this particular symptom. It may also stem from such other issues as uneven tire pressure, a faulty wheel bearing, or malfunctioning brake caliper. With that said, if unevenly-worn pads really are the culprit, two new sets should be installed in one session.
Does the brake pedal violently shake whenever you step on it? Pads might be causing the problem. Brake pads are typically held together with a kind of binding resin. As each pad wears down, this adhesive gets hot and gets smeared across the rotor. Under ideal circumstances, it will form a layer that’s evenly spread over the disc’s surface. But if a pad gets overheated, the resin may not be distributed uniformly. Mechanics call this issue “glazing” and it can cause brake pedals to vibrate.
A pulsating brake pedal isn’t a trustworthy one. If this issue goes unchecked, your ability to brake safely could be compromised. When it comes to brake pad upkeep, stay safe and don’t procrastinate.
If you are experiencing any of these issues give us a call to schedule an appointment for a brake inspection.