What is the braking effect of the brake pads in the automobile braking system? The result was unexpected
Like all auto parts, brake pads deteriorate over time and need to be replaced. They suffer from excessive wear because they are constantly needed by the driver.
The brake pads wear at different speeds and depend on several variables. The mileage of the vehicle, driving habits and the general environment in which the vehicle is used will all have an impact. For example, rural drivers find that their pads have a longer service life than urban drivers who sit in busy traffic and face multiple stops and departures every time they travel.
According to general experience, the service life of brake pads should be 30000-40000 km, up to 60000 km or more, depending on the driving mode and location of the vehicle.
What are brake pads
Brake pad is an integral part of vehicle braking system, which is used to slow down or stop the vehicle. Each wheel relies on brake discs, calipers and a pair of brake pads to ensure its safe stop.
The brake pads are located inside the caliper, and their friction materials contact almost every side of the metal brake disc.
Working principle of brake pad
Each time the brake pedal is pressed, the piston presses against the caliper. Hydraulic oil (brake fluid) from the caliper presses the brake pads against the rotating disc. The resulting friction stops the vehicle under control.
Type of brake pad
There are 3 types of pads, which vary according to price, manufacture and material:
organic
In the 1950s and 1960s, asbestos was used as friction material for brakes because it absorbed heat very well. Asbestos is no longer used because it can become a carcinogen in the air. Therefore, automobile companies have created asbestos free or Nao brake pads. In the United States, almost all vehicles are equipped with Nao brake pads.
Depending on the manufacturer, Nao brake pads are made of fiber, glass, resin, rubber and Kevlar and cured to withstand a large amount of heat. Their softness prevents them from causing damage to the brake discs, but causes them to wear faster than other types.
Nao brake pads are the cheapest and often have the shortest life expectancy.
Semimetal
Semi metallic pads are made of a mixture of synthetic materials and metals and can withstand overheating.
Sintered steel, graphite or iron combine with organic resin to produce excellent heat conduction.
The brake pad has long service life and can meet the high requirements of heavy vehicles and high-performance vehicles.
Ceramic products
Although Nao brake pads have solved the problems related to asbestos, there is still room for improvement. In the 1980s, manufacturers developed ceramic brake pads using the same materials as those in plates and mugs.
The clay in ceramic brake pads is dense and has high friction coefficient. Ceramic brakes are usually embedded with copper plates to further improve their friction coefficient and thermal conductivity.
How long can the brake pads last?
The modern disc brake is much better than the old drum brake; They are safer and have greatly improved braking force. However, brake pads tend to wear faster than old brake pads.
There are many factors affecting the service time of brake pads, including the quality of brake pads and braking system.
Other factors such as friction, pressure and heat determine the service life of brake pads and the driving mode and conditions usually used by vehicles.
Based on the average annual mileage statistics provided by the federal highway administration, the calculated data show that a typical brake pad can be used for 3 to 7 years.
There are many ways to know when to replace the brake pads, but if you need assurance, please ask the mechanic to check each service.
Why do brake pads wear out quickly
Driver error - the most common cause of brake wear is poor sudden braking habits.
Poor quality pads – cheaper pads may contain small pieces of metal that can damage the disc and adversely affect the pads.
Corroded side pins - they will destroy the normal smooth sliding of the caliper. If it is not flush, a small part of the brake pads will constantly contact the rotor and wear faster and unevenly.
Torn piston seal - since it is operated by brake fluid, any tear will cause leakage. If the piston cannot be reset after each movement, it will remain in contact with the rotor, resulting in excessive wear.
Worn rotor (disc) - a rotor with grooves, dents or charring directly affects the speed of brake pad wear. They can also cause the pads to crack or slot, preventing them from completing their work correctly.
Excessive dust accumulation can also lead to brake pad degradation.
How to prolong the service life of brake pads
This may involve minor adjustments to your driving habits to extend the service life of the brake pads.
Install the best brake pads you can afford - high quality brakes have a longer life expectancy.
Driving within the speed limit – sudden braking will exert excessive pressure on the brake pads.
Keep a safe following distance - if the car in front suddenly brakes, you should have enough space to slow down smoothly.
Use engine braking - try to lift your foot off the accelerator and bring the vehicle to a slow, steady stop. Fuel injection stops and the throttle is almost closed, which limits the air flow.
Regular maintenance - worn parts will put too much pressure on healthy parts and try to keep everything in the best condition.
Reduce load - carrying unnecessary weight will increase the pressure and demand of the braking system.
Clean the brake disc - each time you wash the car, use a hose to quickly splash the brake disc to remove dust and debris. Dust = increases friction and wear.
How to determine when to replace the brake pads
Several signs and even special indicators can tell the driver that the brake pad is faulty.
Some brakes are equipped with sensors on the brake pads, which trigger the instrument panel warning light to remind the driver of the need for action.
When the brake pad wear is low, you will hear relevant messages. Inside the brake pad, below the friction material, is a metal wear indicator. As the material wears, the indicator plate contacts the metal brake disc, resulting in a squeak or metal to metal friction sound each time the brake is pressed.
If the car is pulled to one side while you are driving, there may be a problem with the brake pads and uneven wear may occur. Pull over to the side of the road. You may also lose power when the brakes get hot.
The status of the brake pad can also be checked by visual inspection; By observing the spokes of the wheel. If the thickness of the pads is less than 1 / 4 inch, it is time to replace them.
Possible causes are damage to hydraulic system parts, caliper components or handbrake. Sometimes it is due to incorrect bedding in the procedure being performed. Do this immediately after installing a new pad:
Find a safe, open and open road. The quieter the better.
Accelerate to 60 km / h and apply moderate pressure to slow down to 10 km / h
Repeat 4 times to heat the pad
By repeating this process to increase heat, only this time the top speed is 60-70 km / h, down to 20 km / h
If possible, after you do it four times, slide for 10 minutes
Stop and wait at least one hour for the brakes to cool
Last thought
Most drivers realize that braking force is as important as horsepower to the vehicle. Therefore, care must be taken to pay attention to the health of the braking system.
Knowing the service life of the brake pads makes it easier to estimate when they need to be replaced.