– Brakes are pretty much the most important safety device on your car. If you’ve ever partially lost your brakes in the past, you’ll agree that it’s not something you want to experience again. Inspecting your brakes twice a year for wear and damage can protect you and your passengers. Additionally, it will also help save you money by catching any damage before it becomes too costly.
The master cylinder, the heart of the vehicle’s braking system, holds the brake fluid when it is not being delivered to the brakes through the brake lines. If brake fluid leaks because the master cylinder is worn or brake lines are plugged or broken, the fluid cannot be delivered, and the brake pads will become ruined. The brake fluid itself can become dirty or contaminated as it draws rust-causing moisture and picks up other debris, or it can break down from excess heat. Clean brake fluid is either clear or slightly yellow, while dirty brake fluid may be brown or even black.
Old and dirty brake fluid can damage ABS brake systems internally. The brake lines connect to the master cylinder through a combination valve, which combines a metering and proportioning valve. It regulates the pressure on the front and rear wheels to make sure both sets of brakes are applied simultaneously. A malfunctioning combination valve may cause the wheels to lock up. Brake pads and shoes can be made of ceramic, metal or organic materials, while the disc rotors and drums they press against are made of metal. Because the pads and shoes create friction to stop the car, they gradually wear down over time and may wear away completely, letting the metal of the calipers and cylinders they are attached to grind against the rotors and drums and damage them. Some pads have a metal strip attached that sounds a warning whistle when the pad becomes too worn, but this strip sounds only when the car is in motion and the brakes are not applied.
BY JEFFERSON BRYANT | NAPA KNOW HOW | JANUARY 7, 2015
Brakes are often overlooked and taken for granted until you have a significant problem on your hands. When it comes to the most important safety mechanism on your vehicle, letting problems go until that system no longer functions properly is a recipe for disaster. Don’t ignore the warning signs of impending brake failure, keep your braking system functioning at its peak performance. The following is a list of the top ten warning signs that your braking system needs servicing. If you have any questions or concerns at all, CALL THE SHOP
A soft, spongy feel in the brake pedal is a sure sign of a problem in the hydraulic system. Issues such as air in the lines, failing calipers or wheel cylinders, or a weak flex line can feel soft when you hit the pedal. Your brake pedal should be firm and the brakes should feel solid and apply gradually. When the pedal is soft and spongy, your braking system is likely to fail soon. It could be as simple as needing more fluid in the master cylinder.
If the brake pedal is hard to push, the problem is most likely in the power assist mechanism. There are two types of power assists – vacuum and hydraulic. Most cars and trucks use a vacuum booster to provide braking assistance so that the driver doesn’t have to exert as much effort on the brake pedal. Some heavier trucks, and certain turbocharged vehicles use what is called a hydroboost instead of vacuum to do the same thing. A hydroboost uses hydraulic pressure from the power steering pump to assist the braking function. When these systems go down, the brake pedal is hard to push, but the braking system is otherwise functional. If the brakes do not work and the pedal is hard, then there is likely a mechanical issue between the pedal and the master cylinder, such as an obstruction or broken connecting rod.
Power assist failures in vacuum systems are typically caused by a loss of vacuum (disconnected, split or block vacuum line) or a tear in the diaphragm of the brake booster. Hydraulic boosters can seize internally, leak, or run out of fluid. If the the rest of the steering system is functioning normally, but the hydraulic brake booster does not, then the booster itself is likely the culprit.
The hydraulic system is complex, with lots of lines running to the various components, especially in vehicles with ABS. A leak in any one of these many connections will lead to a loss of fluid and air in the system. Eventually, the braking system will fail altogether. The most common leak-prone areas are at the wheels and the rubber flex lines between the hard line and the brake calipers. In rear wheel drive vehicles, there is flex line that runs between the body and the rear axle as well. Brake fluid varies from clear to rusty orange, depending on it’s age and condition. The fluid is very thin and quite slippery. There is slight odor to it. Look for the tell-tale sign of wet inner tires for caliper/wheel cylinder leaks. Brake fluid is not good for paint, another sign of a leak is wrinkled paint near a brake line connection.
Once you wear through the actual friction material on the pads, you are grinding metal on metal, which is a bad.
If you hear noises when you hit the brake pedal, you likely have a mechanical issue with the braking system. Grinding is a metal on metal sound that means the brake pads/shoes are worn out and the base pad is grinding on the rotor. Once you get to this point, braking performance is seriously diminished and the rotors are actively being destroyed with every press of the pedal. Bring your vehicle to your local shop as soon as possible to avoid further damage and an unsafe condition.
When the brakes have been heated up too much, the rotors can develop hot spots, which when cooled, contract more than the rest of the rotor. The result is a warped brake rotor. Once this occurs, every application of the brakes sends pulses through the brake pedal or steering wheel. These vibrations can also be a sign of poor steering alignment, so you should schedule an appointment with US to get the problem checked out.
A dragging brake shoe on the drum can lead to reduced performance in all aspects- acceleration, cruising and braking. This drum had two grooves worn into it.
Hit the gas and the engine revs, but the vehicle is not pulling away as fast is should? The problem could be a caliper or drum hanging up. If you let off the gas (after reaching 35 MPH or so) and the vehicle slows down much faster than it normally does, this is a sure sign of a braking issue. Road grime buildup and faulty caliper/wheel cylinders are the typical cause of this issue.
If you smell a funky burning odor when you hit the brakes, you have a problem. Overheated brakes smell quite bad and are a dangerous situation. If your brakes are smoking, you are burning the pads. Overheated pads develop a glaze on the surface that is slick, and your braking performance will be be greatly reduced. This is a component of brake fade as discussed earlier.
Any time the brake warning light comes on, you need to pay attention. There are two brake lights – the main system and the ABS system. ABS components can fail and allow the rest of the system to function normally, but the main braking warning light means that vehicle has most likely experienced a failure in the hydraulic system and needs to be serviced immediately.
These warning signs are the most common signs of an impending brake failure. If your brakes do not work, you can’t stop the vehicle. Should that happen, follow these steps to stop the vehicle:
DO NOT PANIC. Take a breath, focus and calm down. You can’t do anything if you panic.
Pump the brakes. If the pedal suddenly goes to the floor, there is likely a broken line. Pump the brakes repeatedly. Most vehicles have separate front and rear systems, so a broken line on one half allows the other half to still work. Pumping the brakes can build up pressure in the system, allowing the brakes to work.
Downshift. Let the engine do most of the work. If the brakes have failed, you need to get off the road. Downshift through the gears to reduce your speed so that you can get slowed down before trying to get stopped.
Parking-brake. Unless you have to, don’t just yank the handle or stomp on the e-brake, this will lock up the rear brakes send you in a spin if you are at speed. Instead, use the e-brake to scrub off speed slowly. A hand brake is better for this, but that all depends on your vehicle. If you moving slower than 30 or so, a full application of the e-brake is less likely to send the vehicle into a spin.
Controlled swerving. To scrub off speed, you can use the steering wheel to swerve the car side to side, slowly and deliberately. Don’t just yank the wheel one side to the other, that will cause a wreck. Once you get the vehicle slowed down, you can make harder turns to bring the vehicle to a stop. You are looking for a slow weave, not a hard turn.
If you are in a runaway vehicle, turn on your flashers and honk your horn to alert other drivers that you are in an emergency situation. Most brake failures occur quickly and in situations where you need to stop immediately, so practicing these steps will help you remain calm and get your vehicle as slow as possible before you have a collision, and they may allow you to avoid a wreck altogether.
Your brake system is a critical safety feature in your car, truck or SUV. If our brake inspection uncovers any wear, damage or problems, our Auto Care Brake System Service includes:
Disc brakes consist of a Disc Brake Rotor, which is attached to the wheel, and a Caliper, which holds the Disc Brake Pads. Hydraulic pressure from the Master Cylinder causes the Caliper Piston to clamp the Disc Brake Rotor between the Disc Brake Pads. This creates friction between the pads and rotor, causing your car to slow down or stop.
Drum brakes consist of a Brake Drum attached to the wheel, a Wheel Cylinder, Brake Shoes and Brake Return Springs. Hydraulic pressure from the Master Cylinder causes the Wheel Cylinder to press the Brake Shoes against the Brake Drum. This creates friction between the shoes and drum to slow or stop your car.
Computer-controlled anti-lock braking systems (ABS) are a recently developed safety feature. When sudden stops are made, the ABS prevents wheel lock-up. The system is comprised of wheel-speed sensors that monitor wheel rotation, computer-controlled hydraulics that pulse the brakes on and off rapidly, and the on-board computer. Anti-lock Brake Systems (ABS) ensure that the wheels don’t stop rotating during braking, preventing the car from skidding and offering greater control. If your ABS light comes on, visit us and we will be happy to diagnose and fix the problem.
The Parking Brake uses Cables to mechanically apply the brakes (usually the rear brake.) This is used to prevent the car from rolling when not being driven.
Your vehicle’s brake system is a culmination of over 100 years of technological innovation, transforming crude stopping mechanisms into dependable and efficient equipment. While brake systems vary by make and model, the basic system consists of disc brakes in front and either disk or drum brakes in back. Connected by a series of tubes and hoses, your brakes link to each wheel and to the master cylinder, which supply them with vital brake fluid (hydraulic fluid).
When you first step on the brake pedal, you are triggering the release of brake fluid into the system of tubes and hoses, which travel to the braking unit at each wheel. You actually push against a plunger in the master cylinder, releasing fluid. Brake fluid can’t be compressed. It moves through the network of tubes and hoses in the exact same motion and pressure that initiated it. When it comes to stopping a heavy steel machine at high speed, this consistency is a good thing. The performance of your brakes can be affected when air gets into the fluid; since air can compress, it creates sponginess in the pedal, which disrupts consistency, and results in bad braking efficiency. “Bleeder screws” (located at each wheel cylinder) remove unwanted air in your system.
A car without functioning brakes is dangerous. In many cases, warning signs will tell you if your car’s brakes may need service.
We want our customers to have the opportunity to feel comfortable in their vehicle. You can leave the repairs and services to our professionals, but please don’t hesitate to ask us questions about why a service is needed or how it occurred. We will be happy to speak with you. Here is some valuable information on brake issues and corrective services:
Brake pad problems can usually be identified by squealing brakes. If your brake pads deteriorate completely, you’ll hear a grinding metal-on-metal sound when braking, meaning that it’s too late and you’re ruining your rotors or drums! Those with knowledge of auto repair may be able to fix this at home, but you should always see an auto repair professional immediately if you have brake problems.
In a disc brake system, rotors are attached to your vehicle’s wheels. When the brake pads grip the rotor, they bring both the rotor and wheels to a stop. However, the friction causes grooves and cracks to appear over time. Resurfacing brings the rotor back to a “like-new” condition, reducing squealing and wobbling. We will give your rotors a thorough inspection and recommend your best course of action.
The brake caliper houses your brake pads and fits around the rotor like a clamp, pressing the pads against the rotor when you brake. A brake caliber problem could cause uneven braking, making your car slide forward when you brake. Uneven braking can also cause your vehicle to slide out of control in bad weather conditions, so contact us as soon as possible.
A brake hose is a tube carrying pressurized brake fluid from the master cylinder to the brakes. A crushed hose can cause a lagged or slow brake, and a leak in the hose can cause the brake, or the entire brake system, to fail. These don’t need to be replaced often, but should be replaced at the first sign of cracking or wear.
Brake fluid will absorb water from the air over time, causing the brake system to become less effective and the fluid to become corrosive, possibly damaging the system. It is important to perform a brake fluid flush regularly to ensure that your vehicle is using fresh fluid. Talk to our technicians about when it’s time for a brake fluid flush.
Wheel bearings are found inside of wheels, allowing the wheels to spin freely, and are connected to the brake system. They can become worn over time, causing a vibrating suspension and noisy rubbing as the car is driven. If they break completely, the vehicle will become very difficult to control and unsafe to drive. Replacement interval for wheel bearings varies greatly, but they should be checked for leaks and wear periodically. We can make sure that your bearings are in good shape and let you know if they need replacement.
