I recently took my car to have its brake pads replaced, and I have to be honest, I wasn’t too excited about the bill. No one wants to shell out money to replace brake pads that aren’t completely used up.
When should brake pads be replaced? You should replace your brake pads regardless of miles traveled when they reach ¼ of an inch in thickness or if your brakes become hardened.
Read on to learn more about when brake pads should be replaced and how to check them yourself before you head to the garage.
When to Replace Your Brake Pads
Each time you apply your brake, the brake pads of your car press against the brake rotor, and a small amount of the brake pad wears away.
Brake pads must be changed when they reach ¼ of an inch thickness. If they wear down too far, you may cause damage to your brake system, and you risk brake failure.
Often it is suggested that you change your brake pads every 35,000 to 70,000 miles you travel with them, but these numbers aren’t very useful.
First all there is a big between 35,000 miles and 70,000 miles. Secondly, it may be counterintuitive, but the number of miles traveled is not the best way to estimate how worn your brake pads are.
Your brake pads will wear down more quickly if…
- You drive in a city and have to make frequent stops
- You drive frequently in mountainous or hilly areas
- You drive in an area with cold, snowy winters.
If you do most of your driving across flat terrain in warm weather with few stops, you will not need to change your brake pads as often.
In addition, the location of the brake pads matters. In most cars, the front brakes wear faster than the back brakes.
The kind of brake pads you use in your car also makes a difference. There are three different kinds of brake pads:
- Semi-Metallic
- Organic
- Ceramic
Semi-metallic brake pads are made of metal and synthetic materials. They are the most commonly used brake pads because they perform well in all road conditions, and they are inexpensive.
Organic brake pads are made of a combination of glass, resin, and rubbers. They are quieter, but they wear faster than the semi-metallic pads and cost about the same.
Ceramic brake pads are made of ceramic and fine copper fibers. They last longer and do less damage to the rotor when you apply your brakes. They also cost 2-3 times more than semi-metallic brake pads. (Source)
If you’re wondering what kind of brake pad to use with your car, you should select whatever kind of brake pad came standard with it.
Brake Hardening
Hardened, or glazed, brake pads occur when the brake pads have overheated to such a degree that they lose friction and their ability to stop your car effectively.
If only the surface of the brake pad becomes hardened, it can be fixed with a light sanding. If the entire brake pad becomes hardened, it must be replaced.
Causes of brake hardening include:
- City traffic with lots of stopping
- Steep downhill travel
- Riding the brake
- Excessive panic stopping
How to Check Your Brake Pads
In most cases, all you need to inspect your brake pads is a good flashlight. By looking through the hole in your wheel with a flashlight, you can spot the brake pads on most cars.
- Allow your brakes to rest for at least an hour before trying to inspect them. Brakes can get hot, and there is no point risking a serious burn.
- Get a flashlight and crouch down by the wheel of your car. Try to find the brake pad.
- Once you locate the brake pad, you can examine it.
- Some brake pads have a groove down the middle of them called a wear indicator slot. On fresh brake pads, the groove is deep. On worn out brake pads, the pad will be almost flush with the groove.
If you cannot see the brake pad through the holes in the wheel, then you have to remove the wheel. To do this, you will need a jack, a lug wrench, and maybe your owner’s manual.
- Remove the hubcap following the directions in your owner’s manual to expose the lug nuts.
- Jack up the car about six inches off the ground.
- Unscrew the lug nuts.
- Remove the tire.
- Examine the brake pad as described above.
- To check for hardening, run your hand over the brake pad. Hardened brake pads will feel smooth and look shiny.
Here is a helpful video on how to remove a tire.
There is no need to measure the brake pad if there isn’t a wear indicator slot. If the pad is approaching ¼ of an inch in thickness, it is time to change them.
Warning Signs that Your Brake Pads Need Replacing
Brake Pad Thickness
If a visual inspection of the brake pad reveals that it is less than ¼ inch thick, then it is time to change the brake pad. Your brake pads’ wear indicator slots makes this simple.
Smooth or shiny Brake Pad
If you run your hand over the brake pad, and it feels smooth, or the brake pad has a shiny appearance, the brake pad has likely become hardened and needs to be replaced.
Squealing or Screeching
If your brakes are persistently squealing or screeching, it is probably time to change the pads.
Many brake pad manufactures insert small metal shims into their brake pads so that when they are low, they make a noise, alerting the driver that there is a problem.
Sometimes brakes will squeak after being in wet conditions. This is normal and usually stops after you apply the brake a few times.
Grinding or Growling
If your brakes are groaning, grinding or growling in a deep metallic way, this means you probably don’t have any brake pad left to speak of, and the caliper is pressing into the rotor to stop the car.
This is not only ineffective, but it will quickly cause serious damage to your car.
Indicator Light
Modern conveniences have made checking your brake pads easy. Some cars have an indicator light to let you know when your brake pads need to be replaced.
Brake Pad Dust
As your brake pads begin to wear they produce dust that can make your tire look dirty. If you pay attention to this dust, it could give you a clue about how worn your brake pads are.
When your brake pads are fresh, the dust will be heavier. If you notice that this dust is not as heavy as it normally is, it might mean your brake pads need changing.
This is not the most accurate way of knowing that your pads need to be changed. It is worth taking a peek at the pad to be sure.
Vibrating Brake Pedal or Steering Wheel
Vibrations that occur while you are braking in the brake pedal or the steering wheel could mean you need new brake pads. Of course, there also could be another brake issue.
Cost of Replacing Brake Pads
The cost of new brake pads averages between $100 and $300 per axle, meaning for two wheels (Source).
This does not include the cost of replacing rotors or any other part of the brake system beyond the pads. This price can increase depending on what kind of vehicle you drive.
If you are comfortable working on your car, you can change the brake pads yourself. A set of brake pads, enough to handle two wheels, costs around $50.
But changing your brake pad is not a task for a beginning home mechanic. Getting your brakes wrong has dangerous consequences.