Vehicles are made up of a variety of systems, among them one that is of great importance for safety is the brake system, and one of the vital parts of this system is the brake pads.
Because of the function they perform to stop the car, a periodic review should be made to be aware of the brake pad thickness, as this will depend on driving with efficient safety, without running the risk of accidents, and without the risk of causing damage to other people, drivers, and things.
- What are Brake Pads?
- Types of Brakes Pads
- What Is The Ideal Brake Pad Thickness?
- Brake System
- What are the symptoms of thin brake pads?
- How To Inspect The Thickness Of Brake Pads
- How To Keep Your Brake Pads Under Control Easily
- Is 4mm Brake Pads OK?
- What Is the Legal Minimum Brake Pad Thickness?
- How Long Will 3mm Brake Pads Last?
What are Brake Pads?
Brake pads are a consumable component of the automobile, physically they look like small and elongated pieces, which have a metallic part, and another part made of a material similar to asbestos. They have the function of creating friction with the brake disc to slow down the speed of the car and stop it.
These parts have a specific brake pad thickness that is generally 15 mm when new. And the part that forms the wearable area of the pad has several components, including fiber, which has the function of joining the other components of the material, and the type of fiber used in the manufacture of the brakes pads are minerals and synthetics.
Another compound involved in the manufacture of these pads is the mineral fillers used to provide the mechanical consistency necessary for resistance and to withstand abrasion. Among these mineral fillers are barite, carbonate, feldspar, magnesite, mica, and talc.
Some metallic powders are also used in the form of chips, in order to improve friction and heat transfer, commonly used are bronze, copper, and brass powders. The abrasives increase the friction coefficients and keep the contact surface of the disc with the pads clean. These pads are also known as brake pads and brake shoes.
Types of Brakes Pads
The existing types of brakes pads depend on the material from which they are made, thus we have:
1. Organic Pads
This type of pad has the characteristic of being manufactured with fibers that do not contain metal, combined and reinforced with graphite and metal powder that act as friction modifiers, and with a series of compounds to minimize both noise and heat transfer generated by friction at the moment of braking.
These are manufactured with alloys of steel, copper, iron, and a series of organic materials that provide high resistance to high temperatures and an efficient degree of rigidity.
This type of pad is no longer manufactured as in the beginning, since the use of these has been replaced by the previous systems, and has become obsolete. The basis of its components is the combination of metals at certain pressures.
These are pads made of synthetic polymers combined with fiberglass, forming an aramid – a material with excellent durability, resistance, strength, and very light, also with high capacity to minimize friction heat.
What Is The Ideal Brake Pad Thickness?
Taking into account that the original thickness of the brake pads is 15 mm and that the technical recommendations for their replacement should be made when this thickness has been reduced to 2 or 3 mm.
We can affirm that the ideal thickness that should be maintained in the pads should oscillate in a measure that is in a range between these two measurements, i.e. between 3 mm and 15 mm.
Allowing this thickness to be less, is a synonym for risk, we will explain how the brake system works to understand why having brake pads with a thickness less than the recommended one represents a dangerous risk.
This system is composed of a series of elements among which we have the brake pedal, which is where the braking action is initiated, other components of the system also intervene such as the brake servo, which can be master-vac or hydro-vac depending on its pneumatic or hydraulic action. This element fulfills the function of multiplying the force that the driver applies when pressing the brake pedal.
The brake fluid reservoir, the pipes through which it circulates are other components of the brake system, as well as the discs, drums, and calipers. These are the part where the brake pads are placed, which are pushed towards the surface of the disc by a piece called piston, which response to the hydraulic action that occurs in the circuit through the brake fluid.
This shows the importance of properly maintaining the brake pad thickness, it could happen that by letting that thickness become less than 2 mm. The piston must come out more than normal to push the pad and it would generate a dangerous failure that would trigger a malfunction of the system. The car could lose the brakes because of the piston comes out too much, there will be a loss of brake fluid, and the pressure in the entire system will be lost.
For these reasons, it is vital to periodically and reasonably check the brake pads, the wear of them occurs by the friction of these with the brake disc, usually, the pads of the front wheels wear out in less time than the rear ones.
The durability of the brake pads depends on factors such as the mileage traveled. If these trips occur frequently on roads with mountainous descents, the useful life of the pads will be shorter than when driving on flat roads.
A proper revision of the brake pads should not exceed 20 thousand Km. The most advanced models of cars are provided with an electronic mechanism that issues an alarm to the driver if the condition of the pads requires replacement. This alarm works through a light on the dashboard that turns on when the thickness of the pads has reached the functional limit.
What are the symptoms of thin brake pads?
Although it may seem strange, cars work similarly to people when they are going to get sick. Cars give warnings of possible damage and if these are not attended to the damage, in most cases will be greater and in the case of brake pad thickness very dangerous.
1. Metallic Sounds and Noises
Hearing metallic sounds when braking is a clear sign that there are problems with the thickness of the brake pads, it is a case that requires immediate review and replacement of the pads. Neglecting this warning that is giving the car can mean damage to the discs, in the jaws, can even break a piston.
If the thickness of the pad is less than allowed, the piston will nod by leaving more than determined, and will run the risk of breaking causing damage to other components of the system, and increasing the maximum danger of an accident.
Crystallized noises when braking, in the form of squeaking noises, are symptoms of worn brake pads, a sign that the pads are thin and may be at a thickness less than adequate for proper operation, and therefore should be replaced immediately.
2. Vibration During Braking
Another symptom of thin brake pads is the pulling that the car produces when the brakes are applied, the vibration that can be felt in the brake pedal, and the steering wheel, also require an urgent review of the thickness of the brake pads.
3. Burnt Smell
The smell of burnt brakes when applying the brakes is another symptom of thin brake pads, and perceiving hardness, weakness, and sponginess in the pedal when braking are situations that should be promptly addressed by the respective revision of the brake pads.
4. Flashing Indicator Light
And finally, the indicator light on the dashboard conventionally a circle covered on the left and on the right by a kind of parenthesis and an exclamation point symbol in the center of the circle, which is illuminated in red indicates that the pads are very thin and that their replacement should be done immediately to avoid greater evil and to prevent the risk of accidents.
How To Inspect The Thickness Of Brake Pads
One of the parts of the car that should always be in optimum condition is the brake pads, the importance of this element in the safety of the vehicle and people, so demands it.
The revision of the brake pad thickness should be oriented to the verification that this thickness is not below the established minimum of 2 mm. However already 3 mm is a sign that they should be replaced, this action will save headaches, mishaps, and accidents.
The realization of this revision task requires that the vehicle has a prudential time without rolling, this is so that the brakes are not at a high temperature that can cause a bum. Pay attention to the rims of the car. If the pads are well thick it is normal that there is dust residue generated by the pads. If you see too much cleanliness in the rims, it is a sign that the pads may be worn.
Most brands of brake pads have a slot for wear control, and in many vehicles, the brake pads can be visualized without disassembling the wheels. Just lean with the proper lighting to see if the slot is still visible. If the slot is not observed, the pad has already fulfilled the useful life and must be replaced.
In the case of vehicles that do not allow the observation of the brake pads without removing the wheels, you should suspend the car with a jack, remove the wheel and with the use of a vernier or a small meter verify that the brake pad thickness is not less than 5 mm. Otherwise the replacement by the new ones is the most suitable.
How To Keep Your Brake Pads Under Control Easily
The easiest way to exercise good maintenance on the brake pads is to create adequate and efficient driving habits. Using common sense when driving brings many benefits to the safety of the driver and his companions, and to the vehicle. Since not only the brake system is treated properly, but also all the other components of it
Being attentive and concentrated when driving, and driving at the speeds allowed for each road avoids abrupt and sudden braking. When a driver does not drive at excessive speed but does it in a smooth and conscientious way, minimizes the wear that can occur in the brake pads, extending the life of these, and of the tires.
The correct use of the vehicle’s gearbox is a habit that drivers should put into practice, especially when driving on mountain roads and on steep descents. Reducing the vehicle’s speed by using the gears prevents the brakes from overheating, leading to a decrease in the wear of the brake pads’ friction material.
The fact that the brake pads overheat reduces the efficiency of the braking action of the vehicles. When the brake pedal is abused, continuous friction is generated between the brake disc and the brake pads. This friction generates heat, the high temperature due to the constant braking exceeds the maximum temperature that the pads can withstand for its proper functioning.
These pads are composed of organic substances, which are subjected to solidification processes when they are manufactured, and as all products have limits in the case of brake pads they have limits as to the temperatures they can withstand. If these limits are exceeded, these pad materials suffer a decomposition and release gases that with the high temperature generate overheating minimizing the efficiency of braking. Hence the importance of using the brakes properly.
To combat this phenomenon of overheating in the brake pads, one should avoid descending with the gearbox in neutral, in this position the vehicle descends freely, taking more speed, which will imply more friction at the moment of braking, and consequently an increase in the braking temperature that will generate the overheating of the pads.
The best way to descend is to use a strong gear, such as third, or second in the case of synchronous vehicles, and L, L1, and L2 in automatic vehicles which is an excellent way to keep the brake pads under control.
Another efficient behavior that drivers should observe when driving down long descents is the use of the brakes at regular intervals. The purpose is to slow down the car without constantly braking it giving the brake pads the opportunity to cool down at those intervals.
And lastly, if you notice the brakes overheating without remedy, park the car and wait for them to cool down naturally to continue driving.
Is 4mm Brake Pads OK?
Whether 4mm brake pads are OK depends on the thickness of the rotor. When the rotor is warped, it will squeeze the brake pad, leading to pulsing and vibration while braking. Warped rotors should be replaced when their thickness reaches a certain level. This limit is often specified in millimeters. If your rotor has less than 4 mm of thickness, you should replace it as soon as possible.
Ideally, your brake pads should be between six and eight millimeters thick. However, most car mechanics recommend replacing them when only 20 percent of the thickness remains. In addition, thinner brake pads can cause the brake system to malfunction. The ideal brake pad thickness is 6.4 mm. However, there are many exceptions to this rule, so you should make sure your new brake pads are thicker. Most car owners should stick to 6 mm or thicker for their brakes.
When to replace brake pads, your car’s mileage, driving style, and climate all play a role in the lifespan of your brakes. Ideally, you should replace them every 5,000 miles or five months. A thinner pad may compromise your vehicle’s performance and safety on the road, so make sure to replace them when needed. If you use your brakes too often, you may end up with an unsuitable brake pad.
Changing brake pads is a fairly easy task, but it’s important to follow proper procedures. Brake pads are a critical safety feature of your vehicle and should never be underestimated. Make sure you have someone who has done this before you try it on your own. Watch videos online, read a repair manual, or get an expert’s advice at your local NAPA Auto Parts store. If you’re unsure about brake pad thickness, check it out with a brake expert before proceeding.
What Is the Legal Minimum Brake Pad Thickness?
While there is no federal minimum thickness for brake pads, the UK’s legal minimum is 1.5 mm. New brake pads are roughly 12 mm thick. Most manufacturers recommend changing them after seventy-five percent wear. If you’re unsure of the exact thickness of your car’s brake pads, take your vehicle to a trusted mechanic to check the thickness. Brake pads can wear down to less than half that thickness.
While checking brake pad thickness isn’t always possible, it’s worth a try. Most brake pads have visual indicators, such as a thin painted strip or a slot cut into the material. These indicators fade away with wear, so when you notice them going missing, it’s time for a replacement. Brake pad thickness should be between 1.5 mm and 2.0 mm. This thickness is considered “adequate” for the safety of your car, but it is still worth taking the time to check.
A good pad thickness will make all the difference when you need to brake. A pad with too little material will wear away quickly, leaving the metal backplate pressed against the rotor’s face, reducing stopping power. Thicker brake pads won’t stop a car as well as they should, and this is dangerous for the driver, passengers, and other road users. Lastly, a faulty brake will be unsafe for pedestrians.
What is the legal minimum brake pad thickness? Should I be concerned about the thickness of my brakes? Brake pad thickness is a very important aspect of your car. A thin pad can ruin your car or your driver’s safety, so it’s vital to know how much thickness you need. A few millimeters is considered adequate. Depending on how often you brake and the friction material of your brake pads, you should have at least three-quarters-inch-thick brake pads.
How Long Will 3mm Brake Pads Last?
The thickness would make it very possible for 3-millimeter brake pads to be still useful after around 50,000 miles (more or less). While 50k miles is typical, 20k miles can be more achievable for others.
Keep in mind that some brake pad materials are more durable than others. Steel backing plates, shims, friction materials, rubberized coatings, and thermal insulation coatings are all utilized to make brake pads. These are durable materials, but they will not last indefinitely.
Your brake pads will eventually wear out and need to be changed. Brake pads wear out after around 50,000 miles since they are used every time you step on the brake pedal. However, if you use brake pads that are the correct thickness, your brake pads will last longer.
Keep in mind that the thinner the pads are, the worse they handle the heat and the more likely they are to shatter. In most circumstances, the recommended thickness for replacing brake pads is between 3mm and 4mm.
The brake pad thickness is one of the basic aspects that every good driver should pay attention to. It should be known what is the minimum thickness at which they can provide efficiency, when they should be replaced, and how to drive to get maximum performance from these pads.