To slow down your car, the traditional brake system requires a force acting on the brake pedal, which acts on a fluid in which this force turns into pressure and a friction material at the brake pads, converting the kinetic energy of our vehicle into heat.
Changing brake pads is a common maintenance task to be performed on cars and it’s important because of the life hazards related to their failures.
The most common questions related to brake pads and its replacement will be answered in the following sections.
How long do brake pads last?
Brake-pad’s life-cycle will depend on the type of vehicle, the average force applied to the pedals, and the quality of the pads. For example, in a race-car, the brake pads are changed after every race, and the brake pads used during qualifying and practice laps are not the same used at the race.
For a regular road vehicle, their replacement depends mostly on the driving style of the driver, braking at the last minute, applying a large force at the pedal will make the pads wear faster.
Of course, the traveled distance mentioned above depends on the type of vehicle too, and for trucks and other large vehicles, it is recommended to change them between 25.000 and 30.000 kilometers to ensure that brake power remains constant.
Type of materials used for brake pads
Another influencing aspect of the replacement time of brake pads is the material they’re made of.
Nowadays, brake pads are made from 3 different types of materials. Composites, such as carbon fiber, is used for most high-performance cars;
Ceramics, which gained recognition for their amazing ability to dissipate heat, are mostly used in heavy load vehicles like trucks and performance cars where loads on the brakes are high and stopping distances are short.
Last but not least important, we have Semi-Metallic (CerMet) brake pads, which use a blend between metal and ceramic dust and are used in most stock road car’s brakes. Their importance comes from the ability to dissipate heat added by the ceramic’s dust, and the high load resistance and durability offered by metallic components such as iron, steel, and copper.
When do the brake pads need to be replaced?
The main sign that lets you know your brake pads need to be changed is the loss of brake power.
A squeaking sound when pressing the brake pedal is another sign for replacing your brake pads. In this case, braking power may not be affected but an annoying squeak, as if you were sliding your fingernails against a chalkboard will be present. These sounds come from the wear indicator, which is a metal plate attached to the pads mounting and when the pad reaches a certain wear amount, it touches the indicator while braking, generating these irritating sounds.
One last sign is the excessive dust generation of the pads. When we replace our brake pads with a lower-quality brand there’s a high chance that they wear faster, generating friction material dust that messes up the rims, brake discs, and all the other components around our caliper.
Dust is produced because the pad wears faster as it cannot bear the pressure applied. When buying brake pads its highly recommended to select a good, well-known brand instead of a generic one as the prices will not be so different but the duration of the pads will be extended.
It is always recommended to check the pad’s condition before replacing them to make sure that it has reached its usage limits. To check/replace the brake pads we invite the reader to read the process described in the next section.
How to check and replace the brake pads?
For those who like performing their own car’s maintenance activities, to replace the brake pads you’ll need to follow the steps mentioned below:
- Remove the tire as if you were to replace it, using a hydraulic jack and a cross wrench.
- Loosen up the cap screws that support the caliper in place.
- Carefully remove the brake pads from the caliper. In case the caliper is a fixed type caliper (pistons on each side) you’ll need to remove a pair of cap screws that hold the pads in place.
- Check the brake pads to verify that they need to be replaced. In some cases, the loss of braking power will not be linked to pad wear but on a major problem on the master cylinder or brake lines.
- Using a hydraulic press push the piston in place. Due to pad wear, the piston tends to move from its original position to cover the space previously occupied by the pad.
- Lay the new set of brake pads in place, making sure that there’s a minimum space between the pads and the brake disc.
- Mount the caliper back into place and lock the wheel, you are now ready to use your new set of brake pads.
How much does it cost to replace brake pads?
For the common stock road-car, the brake calipers will be located at the front axle while the rear axle uses drum brakes, this is because the forces applied to the front brakes are higher and drums cannot withstand them. The total amount of brake system service fee is affected by this fact, being drum brakes, in most cases, cheaper to replace.
The cost of the brake pads depends on the materials used and their shape, which is determined by the calipers model. The complete set of brake pads (for both wheels at the front axle) ranges between $30 and $60 for common road-cars and performance vehicle prices can be as high as $120 for each set.
Costs, as the time between maintenance, obviously depends on the type of vehicle, meaning that the maintenance costs for a truck or other large vehicle won’t be the same as for a family car.
To car enthusiasts we highly recommended following the steps described in the section above; this will reduce the costs related to their replacement and you’ll only need the common tools that every mechanic must have inside his toolbox.
Changing the brake pads is a safety-related task and its highly important to keep them in a working condition for your own life safety.