Brake pads should be thicker than 6.4 mm ( around ¼ inches) for proper functioning and safety measures. That makes the wear limit on the brake pad around 3 mm, consider getting a replacement soon if your pads are thinner than this.
What Are the Wear Limits on Brake Pads?
Brake pads are a segment of disc brakes used in automotive and other uses. Composed steel backing plates, brake pads convert the kinetic energy of the vehicle to thermal energy through friction
Most of the mechanics and manufacturers have suggested and agreed upon that the approximate wear limit to the brake pads is 3 mm. Almost all of the new brake pads available in the market are around 8-12 mm thicker. Usually, your brake pads need to be thicker than 6.4 mm, so that they can function properly. Many modern vehicles are provided with wear indicators to warn drivers when replacement is needed.
Changing the brake pads before it reaches its wear limits stops the vehicle from brake failure and future accidents. So, it is important to know the wear limit on the brake pads that you’re using.
Minimum Brake Pad Thickness MOT
At least 1.5 mm of friction material wear is required for the brake pads to pass the MOT. Though manufacturers and mechanics will suggest you replace your brake pads when their thickness is 3 mm, the legal minimum brake pad thickness is at least 1.5 mm.
In the case of the MOT test, brake pads and discs are checked. The advisors will inform you if the brake pads are wearing thin and set you a later date when you need to replace your brake pads.
If the brake pads of your car are 1.5 mm or less than that they will need to be replaced immediately or it will occur in brake failure and future accidents.
Uneven Brake Pad Wear Left Right
DTV or Disc Thickness Variation is the most common cause of unevenly worn brake pads. If your disc has any small difference in thickness, the brake pads will wear down differently over time. And if there is any difference, the thinner parts of the discs will slip through the brake pads easily, where the thicker parts will not.
There is a precaution you can follow when installing brake rotors or discs by yourself, that is using brake cleaners to wipe off the dirt of the surfaces.
Brake calipers are also a reason for uneven brake pads. The guide pins of the calipers sometimes cause the brakes to drag along the rotor when brakes are not being applied. You can get them greased or replaced by your mechanic.
Worn Brake Pads Symptoms
Some worn brake pads symptoms to watch out for:
Making noise
When brake pads get worn out, it starts accumulating a lot of dust on the rotor. The continuous dust accumulation will occur in squealing noises when you press on the brake pedal. As brake pads are created from friction material, this friction material creates dust.
Indicator Warning
This feature is available on new model modern high-end vehicles. There is an indicator light that lets you know when to change your brake pads. There are two sensors, one is on the friction material which creates a signal when making a contact with the brake rotor. The other one is a position sensor that calculates the amount of the pedals that have to move before the brakes are applied.
Slow response
If the brake pads are worn out and you press the brake pedal, it won’t react quick enough. The brake pads will become unable to create enough friction with rotors within time. This might cause serious accidents.
Burning smell
If while driving you smell burning when pressing the pedals, it is because the pads are overheated. Pullover the car immediately to check. And if someone is unable to cool off that heat, the brake fluid might heat up to the boiling point which might lead to brake failure. If you see smoke coming out of that tire, it might be a brake caliper stuck and it’s very unsafe driving with it.
Vibrations
When pressing pedals if you feel a vibration, it might be either because of bad brake pads or brake rotors. This vibration is caused by the brake pad touching the rotor. If either one of them is damaged, it will keep happening.
What Is the Legal Limit for Brake Pads?
The legal limit or the safe MM for brake pads is approximately 3 mm. Though in the UK the legal brake pad limit is 1.5 mm. If your brake pad thickness is 1.5 mm or less you have to change your pads immediately. Though most of the mechanics will recommend you to change your brake pads if they are worn down to 3 mm. Anything less than 3 mm will expose the metal sensor making contact with the brake disc.
At What Thickness Should Brake Pads Be Replaced?
The ideal thickness for your brake pads to work functionally is more than 6.4 mm. But if the brake pads are thinner than this, you need to consider getting them replaced. Up to 6.4 mm thick of brake pads is very functional for brake pads. 3 mm is the legal limit of the brake pads to get replaced. If it’s less than 3 mm, you need to replace them immediately.
FAQ
Q: Can you drive with worn brake pads?
Ans: Continuing driving with worn brake pads will cause a lot of problems and serious issues. It might also occur in a serious accident. You will find harsh squeaking noise, slow response in brake, overheated brake pads, etc.
These things indicate that your brake pads are worn out. And if you keep driving with these worn brake pads, there will be a brake failure and could cause serious accidents.|
Q: How often should brake pads be replaced?
Ans: There are some factors that will let you know how often you should replace your brake pads. Such as:
- Your driving habits
- Environment
- Brake pad hard
- Materials
Usually, after 50,000 miles, the pads need to change. But there are also some of them which last 25,000 miles only while others can last for 70,000 miles. It depends on the above factors.
To Conclude
While getting a replacement for your old weary brake pads, make sure to check out the factors such as Maximum Operating Temperature (MOT), weather performance, pad and rotor lifetime, friction response to temperature for durability, and better performance. And lastly, know exactly when you need to change the pads, safety comes before anything else.
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