Your brake system is arguably the most important safety feature on your car. Without it, stop and go traffic would be a nightmare. The brake system is full of components that work together to slow your vehicle from highway speeds to a complete stop. Some of these components are designed to last the lifetime of the car, whereas others such as your brake pads are wear items that you must occasionally replace to keep your brake system performing optimally.
Function of a Brake Pad
As the wheels on your car turn, your brake rotors turn right along with them. In order to stop your car, you must apply friction to the brake rotors in order to eventually stop the motion of your car’s wheels. Brake pads are the component responsible for applying friction to the rotors. The brake pads are typically housed in a caliper, which forces your brake pads against your rotors each time you apply your brake pedal. As you can imagine, two materials rubbing together frequently at high speeds creates significant heat, which can wear pads and diminish brake performance (in the form of brake fade). Based on the nature of their use, the pads are a high-wear item that will be replaced more than any other component in the brake system.
Common Symptoms of Bad Brake Pads
Brake Indicator Light – Many modern cars have electronic brake wear indicators. When your brake pads wear beyond the minimum thickness, an indicator light will illuminate on your dashboard, indicating that it is time to inspect and replace your brake pads.
Noisy Brakes – Depending on the design of the brake pads, when the pads need to be replaced they will often start to become noisy. Many have a wear indicator that touches the rotor surface when they wear beyond a certain point that is designed to make noise. The indicator produces a squealing or grinding sound intended to alert the driver that the pads are due for a change.
Pulsating Pedal When Braking – As the brake pads and rotors wear, they become more prone to heat related warpage. That heat can induce a pulsation that can be felt through the pedal and can be sensed by your foot. It may or may not reduce the braking performance of your vehicle initially, but a pulsing pedal is a clear sign that your brakes need to be inspected and replaced.
Poor Brake Performance – Failing brake pads can cause poor performance resulting in longer stopping distances and higher brake pedal effort required. When you notice there is a change in your car’s braking performance, it’s time to investigate why and replace parts as needed in order to regain the performance you’ve lost.
Replacing Brake Pads
It is recommended to replace both front brake pads at the same time and similarly both rear brake pads at the same time. You should never replace only one pad, however it’s ok to replace just the fronts or just the rears so long as you do them as a set. It is also a good time to inspect your rotors and replace as necessary since most of the brake pad replacement steps overlap with brake rotor replacement steps. It is always recommended to wear eye protection and a set of sturdy working gloves to protect your hands from busted knuckles as some of the bolts for this project can have pretty high torque and can take some strength to break loose.
Note: The example steps below are intended for general informational purposes solely to help give you an idea of project difficulty and tools required. As all cars are engineered differently, repair procedures and safety hazards vary from vehicle to vehicle. To ensure that you have a vehicle specific repair procedure and an exhaustive list of potential safety hazards, we advise you reference a factory service manual for your vehicle. Similarly, referencing a repair manual such as Chilton or Haynes might serve as a less expensive alternative.
Step 1 – You will need to lift the vehicle off the ground using a floor jack in order to remove the wheels and tires. You will also need to support the vehicle using jack stands. Make sure to loosen the lug nuts with a lug wrench slightly before lifting the vehicle otherwise your wheels will spin as you try to loosen them. Once the vehicle is in the air and the lug bolts have been broken loose, you can remove the wheels and tires completely.
Step 2 – The next step is to remove the brake calipers. Work on one side at a time. Each caliper should be held in place with a handful of fasteners that you can remove with a socket & ratchet set. You might need a small socket extension depending on your vehicle. If the bolts are especially tight, some rust penetrant and a breaker bar is usually enough to break them loose. When the calipers are removed, make sure you do not allow them to hang by the brake hoses. The tension from hanging can damage the hoses causing them to leak.
Step 3 – When the calipers have been removed, you will next remove the old brake pads from inside each caliper. Typically they just slide in place for most modern vehicles. Once the old pads are removed out of the caliper, you will need to compress the piston into the brake caliper before you can install the new pads. You can use a specific brake piston compressor called a brake caliper wind back tool, or a larger C-clamp if you are careful to achieve this. You may need to slightly open the bleeder valve to allow the pistons to compress back into the caliper as forcing brake fluid back through the lines can damage internal check valves and anti-lock brake systems on some models. To prevent air from entering the system, you can use a brake bleeder cup with new fluid to prevent air from going into the caliper.
Step 4 – The new pads will slide in place of the old ones. When the caliper is ready to go back on, make sure the rotor is clean prior to install. A quick spray with brake cleaner and a wipe with a clean microfiber towel or similar will remove any debris on the rotor surface.
Step 5 – Reinstall the calipers. You should follow the manufacturer’s guidelines regarding the use of thread locking compound for the fasteners at the time of install to prevent loosening later on. Torque the fasteners for the calipers to manufacturer’s specs using a torque wrench.
Step 6 – Even if you didn’t open the bleeder screw to compress the caliper piston, it is good practice properly bleed the brake lines and calipers after the new pads are installed. This will ensure that you have no air in the braking system which will give your brake pedal a firm and positive feel rather than a pedal that feels spongy and unpredictable. To accomplish this you can use a brake bleeding kit.
Step 7 – Once all calipers are reinstalled with new pads, you can reinstall the wheels and tires by placing them onto the hub and securing with lug nuts. Snug each lug nut to ensure the wheel is sitting flat on the hub surface. The vehicle can then be lowered to the ground. Once the vehicle is on the ground, torque the lug nuts to the manufacturer recommended torque with a calibrated torque wrench. Bolts are typically torqued in a star pattern.
Step 8 – Check the fluid level of your brake fluid in the Master Cylinder Reservoir to ensure that you are above the minimum level required for safe driving. Add fluid from a new bottle of brake fluid as needed to be above the minimum line. Sometimes swapping pads can actually increase the level of brake fluid since the caliper pistons are less extended due to the thicker pad material, in which case you may need to remove fluid to bring the level back below the maximum. For this you can use a syringe or even a turkey baster but be careful not to get any brake fluid on your paint as brake fluid can damage paint quite easily. Make sure you close the master cylinder cap once the brake fluid is at the correct level. Also be sure to read the owner’s manual for your vehicle to ensure that you get the right type. The most common types manufacturers recommend are DOT3, DOT4, and DOT5. Make sure you put the correct one in your vehicle and avoid mixing and matching.
Step 9 – Take the car for a drive to make sure everything is in good working order. The brake pedal should feel firm. If the brakes feel soft and squishy, you may need to re-bleed the brake system to remove air in the lines. Make sure to check for any leaks as well to make sure everything has been reinstalled correctly.
Best Brake Pad Brands
When it comes to selecting a replacement set of brake pads for your vehicle, there are many brands out there to choose from. To help narrow your search, we have provided our favorite three brands that we highly recommend as we have found them to work great for us over the years.
Brembo is well-known for their motorsports involvement, and the benefits of that knowledge trickle down to their replacement parts available for your vehicle. They have plain old replacement pads with good quality, and also manufacture calipers and complete brake sets to add more stopping power to your vehicle. In enthusiast circles, they are well regarded for their big brake kits, vented and cross-drilled rotors, and variety of performance brake pads. Overall, you can’t go wrong with a set of Brembos.
Click here to find a set of Brembo brake pads for your car.
Powerstop offers a range of brake pads from simple OEM replacements to high-performance parts. Whether you just need something to drive every day, or want to upgrade to more braking power, they offer pads and matching rotors for your vehicle. They also offer complete kits, as well as braking sensors to complete your replacement. Their quality is consistently good, and they are often sought after by driver’s who enjoy driving on the track or at autocross events due to the performance value.
Click here to find a set of Powerstop brake pads for your car.
EBC Brakes has a product line that covers OEM replacement parts and high-end racing components for most vehicles. Their parts are budget friendly, and are consistently ranked high in quality. They offer pad replacement sets or complete pad and rotor kits for most vehicles. They brand their different pads by color, with the EBC Greenstuff and EBC Redstuff brake pads being the most popular for performance oriented drivers who intend to use their car on the street. It’s hard to go wrong with a set of EBC pads.