January 13, 2020
How Do Brakes Work?
The care and replacement of brake components isn't based on the number of miles driven, like many other items. It really depends on the type of brake pads you have and the type of driving you do. If your commute is on roads with few stops, your brakes may last longer. Being in stop and go traffic every day is harder on your brakes. Some drivers are heavier on their brakes than others, causing additional wear. That is why it is important to be aware of the signs that brake components need maintenance and handle it proactively when it happens.
Most cars and small trucks have disc brakes on all four wheels, which consists of a brake disc (or rotor), the brake caliper assembly, and a pair of brake pads. The pads are the part of the brake that provides the friction, and the stopping power, of the whole assembly. When you press the brake, these pads are pushed by the hydraulics in the brake caliper assembly against the rotor, causing this friction. Every time this process occurs, there is some wear on the brake pad and the rotor. Brake pads especially need to be replaced as they wear down.
The rotors do not need to be replaced as often as the brake pads. The rotors will also last longer if you make sure to do regular replacement of the brake pads so that the worn brake pads don't damage the rotors. The rotor will usually last through two to three brake pad changes before showing signs of wear.
There are various types of brake pads that are available, and many manufacturer variations on each type as well. The different materials used within the brake pad compound are designed for different temperature demands and braking needs. As a car owner, researching your options can allow you to fully optimize your vehicle's braking capabilities and stopping power.
Organic/Non-metallic Brake Pads
These are sometimes referred to as NAO. Organic, or non-metallic, brake pads are made from materials such as high-temperature resins, fiber, glass, rubber, or Kevlar. They used to frequently be made from asbestos, but that changed when the health hazards of asbestos were realized. These types of brake pads are softer than the others and are very easy on brake discs. Because they are so soft, they wear away quickly and create a lot of dust. The increased amount of brake dust caused by organic brake pads tends to cover nearby components as well, leading to even more maintenance.
Organic brake pads are not good for anything more strenuous than daily driving, considering how quickly they can deteriorate. These can be used in compact cars to enhance their smooth operation. Larger vehicles, such as trucks or vans with lots of passengers, should look for something a bit heavier duty for their needs. Even as a smaller vehicle owner, it is important to note that if you choose to use organic brake pads, they will require replacing and upkeep much more often than other types of brake pads.
Semi-metallic Brake Pads
Semi-metallic brake pads are generally made of 30% to 65% percent metal materials, such as wire, copper, graphite, iron, or steel wool, and bound together with an organic resin. These brake pads are more resistant to wear than organic brake pads, but are harder on the brake discs. They do require regular maintenance, but will not require replacing as often as an organic brake pad would.
Semi-metallic brake pads are seen in most manufactured cars today and do well for everyday use for most people. They are a safe option for heavy vehicles or hill driving when you need your brakes to work quickly and effectively.
The biggest drawback when it comes to semi-metallic brake pads is that they don't do as well in cold weather due to the lower friction coefficient in low temperatures. This means that the driver would have to apply more brake pressure to get the same amount of braking power when it is cold out. Semi-metallic brake pads can even be used in high-performance vehicles if combined with the proper ductwork for cooling.
Low-metallic NAO Brake Pads
Low-Metallic NAO brake pads are pretty much a mixture between the organic brake pads and semi-metallic brake pads. They are based on an organic mixture but have small bits of metal (generally copper or steel) as well. The metal aids in heat transfer and allows the brakes to work better. Low-metallic brake pads are not common, as they are very dusty and very noisy. That said, they do offer a medium point between organic brake pads and semi-metallic brake pads, and certainly do have their uses.
Ceramic Brake Pads
Ceramic brake pads are not very common, and are typically only seen in very expensive, high-end sports cars. While they are excellent performers, they are simply not cost-effective to put in the majority of vehicles. The ceramic brake pads have a ceramic compound that is very good at absorbing heat from even the most heavy and continuous braking. There are also small amounts of clay and copper to increase both durability and the coefficient of friction. They also put minimal wear on the brake rotors.
While ceramic brake pads can take the constant abuse of consistent race driving, they are not good for everyday driving. In everyday driving, ceramic brake pads rarely reach their optimal operating temperature. This can actually cause a decline in performance in the case of many vehicles and would end up being a waste of money.
Sintered Brake Pads
Sintered brake pads are considered to be more of a hybrid brake pad, rather than its own specific type. They are a composite including ceramic, so they can withstand a higher heat threshold than normal semi-metallic brake pads. Sintering is a process that fuses the metallic particles under high heat to increase their strength. Sintered brake pads are more durable than semi-metallic brake pads and are also more expensive. Sintered brakes are very common in motorcycles and ATV's.
As you can see, each type of brake pad is designed for a different type of application, and there are pros and cons to each one. Semi-metallic brake pads are the most versatile for everyday drivers, even though they are hard on the rotors. Organic brake pads are too soft for most everyday use, and ceramic brake pads are also not suitable for everyday use, but make an amazing addition to a car used for racing.
Manufacturers of brake pads do offer different compounds than the four main types listed above to best offer a brake pad to suit each individual's needs. For instance, some manufacturers will add some ceramic into regular semi-metallic brake pads to market towards people who have a more performance-oriented car. There are many different hybrids available that mix aspects of the different varieties to get the proper brake pad. It is recommended that you choose one that suits the combination of the car you drive, what kind of driving you do, and the type of performance you are looking for.
Which Type of Car is Best for Which Brake Pad?
Compact Car / Sedan - If you drive a compact car, non-metallic brake pads are generally considered fine, as they are quiet and inexpensive. A smaller car doesn't need a lot of stopping power, and these brake pads are enough to provide the stopping power required of such a car. If you have a midsize car, you probably want to upgrade to a low metallic set of brake pads for the additional stopping power needed for the larger size vehicles.
SUVs / Vans / Trucks - Anything larger need sheavy-duty brakes with a high metal content, like the semi-metallic or sintered varieties.
Sport Cars - The best performing brakes for these are ceramic brakes, but semi-metallic brakes may be sufficient depending on your needs.
Racing / Aggressive Use - The best brake pads for these situations are sintered brake pads, as they work best at dispersing the heat and regulating the temperature of your brake pads.
Purchasing brake pads that have some additional performance characteristics can greatly improve the performance of your vehicle. Each vehicle and driver are different, so there is no one best type. It is also important to consider that brake pads are not the only thing that affects the stopping power of your vehicle. Equally important to your brake pad choice is your choice in tires. Your tires are the point of friction between the vehicle and the road. If the tires are not high quality, then changing your brake pads will not have the performance improvement you are looking for.
It is always recommended to read the owner's manual for your vehicle to see what type of brake pads are recommended and why. This doesn't mean that you have to abide by this suggestion per se, but it is a good baseline to start with and may give you some insight in order to make the best decision.
There are many factors to consider beyond just the ability to stop your vehicle. Different materials and compounds affect the ability to withstand heat, durability, noise, and the amount of dust they create. Be careful to research different brands as well. While it may be tempting to find the type of brake that you want and just go with the lowest price, they may not all be the same quality. Low-quality brake pads may not be as reliable or durable, which will be something that will cost you more in the long run.
Once you determine which brake pad best suits your vehicle, location, and weather patterns, you can purchase an OEM set and change them yourself. You can purchase high-quality brake pads, rotors, and other parts for your vehicle at Suburban Auto Parts.
Signs Your Brake Pads Should Be Replaced
It is import to keep an eye out for signs that your brake pads need to be replaced. If you are noticing 'squishy' brakes, vibrations, decreased stopping power, or anything else that doesn't feel right, make sure to get your brakes looked at. A grinding sound may indicate that the pads are completely worn through and the rotors are being damaged. If you are hearing a squeal, that usually means your brake pad has an included wear strip, which is a piece of metal in the pad when it wears to about 1/4 inch, meaning it should be replaced.
In addition to listening and feeling for signs that the brakes need to be replaced, you may be able to visually check your brakes as well, depending on the type of vehicle you have. If you look at the wheels of your car, you should see brake dust, which is a normal accumulation from brake usage. If you notice the amount of dust increasing, then your brake pads may be worn and need to be changed.
Additionally, you can see the brake pad through the wheel on many cars. Some brake pads have a slot in the center to indicate the amount of wear. If your car has one of those, you should be able to easily see if the brake pads are due to be changed. If there is no wear slot, look at how thick the brake pad is. If it is a quarter of an inch or less thick, it should probably be changed.