Brakes are frequently used in vehicles but can be used in other moving machinery. Brake rotors that turn with the wheels are attached to the wheels.
When the brakes are engaged, brake callipers compress the brake rotors. In order to lessen the amount of friction caused by metal on metal, a brake pad is placed between the rotor and the calliper. The pads need to be replaced over time.
If the brakes are applied suddenly, the car may pull up to a stop sign or make a screeching noise. These are signs that the pads need to be replaced.
Well, in this reading, I’ll explore what a brake pad is, its functions, diagram, types, and how it works. I’ll also explore its symptoms, replacement, and how to fix a brake pad.
Let’s begin!
What is a Brake Pad?
The majority of cars used a wooden block as their brake until the 1890s. The vehicle stopped when the driver depressed a lever, which in turn caused the block to scrape against the wheels.
The wooden block stopped being the most effective braking technique once cars started moving faster (over 10–20 mph) and wheels became more sophisticated.
The first remedy was created in 1898 by inventor Elmer Ambrose Sperry: a car with front-wheel disc brakes and brake pads that “pinched” the rotor or disc, operating similarly to bicycle brakes.
The brake pad is a thin block that presses against the disc in a disc brake, typically one of a pair. In automobiles and other applications, brake pads are a component of disc brakes.
Steel backing plates make up brake pads, and friction material is adhered to the surface facing the disc brake rotors. Each wheel’s brake calliper, brake disc, and brake pads make up the usual vehicle braking system.
The calliper is designed to hold the pads, which have their friction material virtually touching the brake disc’s two sides.
Hydraulic fluid in the calliper pushes each brake pad on either side of the rotating brake disc when the brake pedal is depressed. The friction that arises from this causes the car to slow down and eventually stop.
In disc brakes, each disc rotor typically has two brake pads that function together. A calliper attached to the wheel hub or suspension upright holds them in place and controls their movement.
However, for the best performance, racing callipers might use up to six different types of pads with different frictional properties arranged in a staggered pattern.
Related: What Is Brake Rotor Resurfacing? Its Signs and Benefits
Functions of A Brake Pad
By friction, brake pads convert a vehicle’s kinetic energy into thermal energy. In the brake, two brake pads are positioned with their friction surfaces directed toward the rotor.
The hydraulic calliper compresses or squeezes the two brake pads against the rotating rotor to slow down and stop the car when the brakes are engaged.
A dull grey coating is left on the disc as a result of the friction material from the brake pad being transferred onto the disc in small amounts as it heats up in contact with the rotor.
Due to the application of friction material to both the brake pad and disc, friction is created between them that stops the car.
Diagram
Types of Brake Pads
Here are the most common types of brake pads:
Non-metallic (organic)
Non-metallic brake pads are the softest type of brake pad available. They are produced and cured to withstand a significant amount of heat and are composed of various combinations of glasses, rubbers, and resins like cellulose, as well as a sparse amount of metal fibres.
The resulting composite is soft and quickly degrades, yet it is kind on brake discs. They are therefore inadequate for use in any situation other than daily road driving, and even then, a more metal-based pad is recommended to prevent needing to replace them frequently.
Semi-metallic
The majority of the cars sold nowadays come with these types of brake pads. To create a hybrid compound that is primarily made of metals, they combine synthetic materials and metals.
Once the fibers’ composition has been determined, an organic resin is used to bind them together. To increase their durability, they are then molded into certain forms and baked for three to five hours in a furnace.
However, because metal has a lower friction coefficient at low temperatures than the more malleable synthetic material, slightly more pedal force is required to produce the same braking force with the semi-metallic pads when cold.
This is because metal has a lower thermal conductivity than the purely organic variants.
Ceramic
If brake fade still occurs with a set of steel brake pads as a result of overheating, then investing in a set of full ceramic brake pads would be worthwhile.
The ceramic compound employed in these high-spec pads, which are only available for the priciest supercars because of the sheer cost of production, is incredibly effective at absorbing heat from very hard, continuous, violent braking.
This means that they can continuously recover from any demands made on them, including those in activities like endurance racing.
However, because of this characteristic, ceramics can be challenging to warm up to operating temperature, which can be problematic for daily driving.
How Do Brake Pads Work?
Simply explained, the friction created by contact between your brake pads and rotors slows and stops your car. Brake pads are a part of a complex system that depends on each of its components to operate securely and effectively. Your brake pads’ role is as follows:
- When you press the brake pedal, a cylinder opens, sending brake fluid down the pipes to the calipers.
- Your brake pads are engaged by the calipers.
- The rotor, which is directly attached to each wheel, is subjected to pressure from your brake pads.
- The friction produced by this pressure is what allows your car to slow down or stop. Your wheels slow down along with the rotor.
- The brake pads loosen, fluid flows back up the hoses, and your wheels resume motion when you lift your foot off the brake pedal.
Symptoms Of A Bad Brake Pads
You’ll experience the following symptoms in your car when the brake pad goes bad or is faulty: squeaking or squealing sound, grinding noise when the brake is applied, the brake light indicator comes on, the brake pad will be thin, it takes time to stop the car, and finally, vibration when braking.
1. Squeaking or Squealing Brakes
One of the first symptoms of bad brake pads most people notice early is the squeaking or squealing noise emanating from the brakes. Overly worn-down brake pads are frequently the cause of the squealing.
When your pads are worn out, you will begin to hear a grinding sound. At this point, the rotor will begin to be damaged, which will increase the cost of repair.
2. Grinding Noise When braking
Your brake pads need to be replaced right away if you hear grinding noises when pressing the brake pedal. Some brake pads come equipped with metal wear indicators that emit a loud noise to let you know when it’s time to change the brake pads.
You risk much greater damage and more expensive repairs if you allow the brake pads to continue grinding. Learn more about grinding noise when braking
3. Brake Pad Indicator Light Comes On
Most modern automobiles come equipped with brake warning lights, which are typically situated on the instrument cluster. These lights include the primary brake light, the ABS light, and the parking brake light. In most cars, you may also find a brake pad indicator light.
When there is an issue, your brake light won’t always come on, since it also turns on when your parking brake is used.
4. Your Brake Pads Appear To Be Thin
You can quickly assess the condition of your brake pads by touching them for wear. To do this, locate your brake pad, which is typically between the spokes on your wheels.
You should probably replace your brake pads if they appear to be less than 6.4 mm thick, or half of an inch, and if brake dust is present.
5. Car Take Longer To Stop
Loss of performance when applying the brakes is yet another notable sign that your brakes need to be examined.
If you notice less-than-ideal stopping distances when applying the brakes, it could be an indication that your brake pads are worn out or that your brake fluid is low (typically as a result of a leak).
You should visit a brake mechanic as soon as you can to ensure that you maintain all braking abilities and to get a true knowledge of what is going on with your brakes.
6. Vibration When Braking
Vibration when braking is one of the obvious signs of a bad brake pad. If your brakes are in good condition, your car will smoothly stop. However, worn brake pads or damaged rotors can cause vibrations in the car.
If the car shakes or the steering wheel vibrates when you brake but stops when you release the brake pedal, it’s time to have your brakes serviced.
What Factors can Affect How Long Your Car Brake Pads Last?
To know how long your brake pads might last, it’s important to consider the following factors:
Where you drive
Your brake pads may last longer if you conduct most of your driving on highways than if you travel more in inner cities and on shorter trips.
Because driving through cities sometimes necessitates stopping and starting at traffic lights, roundabouts, and junctions, your brakes are required far more frequently than they are when driving down a highway.
How many miles do you cover?
Although it varies depending on the sort of road you’re on, you use your brakes more frequently, and your brake pads wear down more quickly the more miles you log.
That’s all there is to it. Because the front brakes bear more of the braking load, they often deteriorate more quickly than the rear brakes.
Type of brake pads
The durability of the different types of pads you can have in your car varies as well.
- The cheapest brake pads are often made of organic materials; however, they last less time. Low metallic brake pads can be noisy, but they last a little bit longer than organic brake pads.
- Sintered or semi-metallic brake pads combine various materials with fused metal particles, like copper and bronze. Although they have a long lifespan and provide good braking performance, they may cause brake discs to wear out more quickly than other pads.
- Ceramic brake pads are more durable and have a longer lifespan than other materials. The disadvantage is that these also cost more than other options.
The weight of the car
The weight that is routinely carried by the vehicle, such as four or five passengers, a completely loaded trunk, pulling a caravan, etc., is another influence on brake pad wear. It is simpler to slow down and stop with less braking force when the vehicle is lightweight.
A vehicle carrying a 5-person family will obviously weigh more than one carrying, say, a couple. As a result, stopping it in the same period of time will need more force and place a larger strain on the brake pads.
Related: What is Brake Light Switch? Its Diagram and How its Works
What Else Is Checked During A Brake Job?
The brake rotors’ thickness is tested, and any evidence of scoring, abrasion, or uneven wear is examined. For damage, scuffs, and other flaws, the brake disc is examined. There is a check on the reservoir’s braking fluid level.
the car’s suspension system will likely get a fast once-over from the mechanic, along with checks for leaks below the car and the condition of the brake lines.
While they have the chance, they could also examine the state of your wheel bearings and steering system as these are simpler to access while a wheel is off.
It’s simple to physically inspect the condition of your car’s braking system, and mechanics won’t replace a part unless it’s almost worn out. Just ask the technician to show you the replacement parts and their level of wear.
They will be delighted to demonstrate the damaged components and discuss why replacement was necessary.
Conclusion
In conclusion, brake pads are essential parts of a car’s braking system and play a crucial part in providing reliable stopping power. Their importance comes from their capacity to transform kinetic energy into thermal energy, which eventually causes the vehicle to stop.
These small yet essential components are made of a variety of materials, such as organic, semi-metallic, and ceramic, each with certain benefits and characteristics. When brake pads press on brake rotors, friction is created, which slows down and stops the vehicle.
Vehicle owners must be aware of the meaning, functions, types, and workings of brake pads. Maintaining optimal braking performance and guaranteeing road safety requires regular inspections, maintenance, and the prompt replacement of worn brake pads.
Brake pads are a prime example of how seemingly unimportant parts have a significant impact on a vehicle’s overall functionality and safety.
FAQs
What is a brake pad?
Brake pads are a component of disc brakes used in automotive and other applications. Brake pads are composed of steel backing plates with friction material bound to the surface that faces the disc brake rotors.
How much does it usually cost to replace brake pads?
On average, it costs $100-$300 per axle to replace the brake pads in a vehicle. In other words, replacing either the front or rear brake pads would be $100-$300, and replacing both the front and rear brake pads would be $200-$600.
How do you know if brake pads need replacing?
If your brake pads are worn, you may experience screeching while braking, heavy vibrating, or your car pulling to one side as you press down on the brake pedal. You may also find it takes longer than usual for your brakes to slow your car down. A warning light will also help flag any problems with wear and tear.
How often should brake pads be changed?
your car’s brake pads should be replaced every 25,000 to 65,000 miles, while your rotors should be replaced between 30,000 and 70,000 miles. However, the exact figure can vary depending on your terrain, weather conditions, and driving style.
How many brake pads does a car have?
In most cars, each calliper has one inner pad and one outer pad. That’s a total of four pads on a car with front disc brakes and 8 on a car with front and rear brakes. New cars with electronic parking brakes often have separate parking brake callipers on the rear wheels.
How can you tell if your brakes are bad?
- Your brake light is on.
- Squealing, Squeaking, or Grinding Noises.
- Vibration When Braking (Or In Your Steering Wheel)
- Leaking Fluid.
- Spongy or soft brake pedal.
- Burning Smell While Driving.
- Car Pulling to One Side When Braking.
What sound do worn brake pads make?
The brake pad wear indicator in most cars is made from steel. When it hits the rotor, you hear a squeal or squeak. Worn pads are ineffective and dangerous to drive on. If you hear this sound, it’s time for service.