FAQ
A :
The approximate lifespan of a brake pad varies depending on car type and driving style. It takes around 40,000-50,000 km for compact cars (small cars), 30,000-40,000 km for sports cars and around 20,000-30,000 km for RV cars. However, different conditions of use, whether in area, passengers, speed or, brake frequency also greatly influences the lifespan of brake pads (1/3 to 2 times the above-mentioned lifespan). The lifespan mentioned above is based on the pad being used up to the limit of its thickness. However, it would be safer to change the pad earlier than such replacement period. Particularly, the thickness of pad friction materials should be checked after driving distance reaches around 30,000 km for compact cars, 20,000 km for sports cars, or 15,000 km for RV cars. Pad changing is recommended if 5 mm or less remains.
→ As specified in the maintenance corner, the pad will be worn out around 10-15% faster in the case of sport-driving use. Additionally, checking is obviously required every time braking is severe due to circuit running etc.
A :
There are 2 main purposes for cooling down the brakes:
1) For cooling down brake pads and rotors; Although it may be different depending on the outside temperature, pad performance will be sufficiently secured if the pad temperature reaches 100°C or below.
2) For cooling down the brake fluid; especially in the case of hard usage, it is necessary to cool down the brakes to prevent vapor.
Lock (the brake fluid is boiled and then becomes no brake) in next driving. Ideally, it is time to cool down and should be able to run for 20-30 minutes with no braking. However, it is actually dangerous, so there is no doubt that cooling down the brakes is needed by stopping for about 1 hr.
Q : Should a vehicle use both front and rear pads made of the same quality by the same manufacturer?
A :
It depends on the intended purpose for the pads.
In the case of requiring similar performance as genuine products (effectiveness, squeaking, rotor aggression, etc.), you should use the genuine products or products of comparable quality as the genuine products.
Normally, the genuine products use different materials for front and rare pads. There are also cases of production by different manufacturers.
If the effectiveness of general driving is considered, it is good to apply sports pads for both front and rear. However, applying only the front pads also gives similar efficacy.
Generally, a stable effect can be obtained by using the same manufacturers and same material quality for both front and rear pads. Under normal circumstances, the changing of materials or manufacturer does not matter that much. However, please be sufficiently careful about vehicle stability and effectiveness at high load, etc.
In the case of circuit running, please use high-temperature resistant pads (SEI sports pads CS). It is also recommended to apply both front and rear pads from the same manufacturer.
A :
When darting on a gravel road, the brakes will take several G to 15 G of vertical
acceleration (about 1/3 to 1/2 on horizontal acceleration) (1 times of 1 G weight). As a result, pads and calipers will vibrate up and down, left and right, while the piston will be hit. Eventually, the clearance between piston and pads will become larger and the pedal stroke will become longer (called Knock-Back). Even in a case of sudden steep turn, rotor will collapse and the clearance will become larger in the same way. For the opposite brake type, Knock-Back is difficult to occur since the floating part is lighter compared to the floating type.
A :
When the temperature gets high (400°C or more), the strength of the rotor itself (usually made of cast iron) will weaken and the hardness of the surface will soften. Meanwhile, the materials contained in brake pads include metal-component materials such as ceramics and steel, which are difficult to soften even at high temperatures. They are easier to cause damage to the rotor’s surface. It is said that the pads that are singled out as being so-called metal or ceramic are highly aggressive to rotors.
A :
Even if using thin brake pads, fade performance is not typically affected. However, fade performance will be worse if it deteriorates due to severe usage. Rather, vapor lock will be a concern when using thin pads. Therefore, it is recommended to change the pads as soon as possible.
A :
While driving, there may be a condition that the rotors lose contact with the pads, causing the piston to retract excessively. This situation is called “Knock-Back” and the pedal will get in at the next braking. It would be good if the driver steps on the pedals several times without hurrying. Even when using thin brake pads, fade performance is not significantly affected. However, fade performance will be worse if it deteriorates due to severe usage. In the case of severe usage, vapor lock will be a concern when using thin pads. Therefore, it is recommended to change the pads as soon as possible if the thickness of pad friction materials reaches 5 mm or less.
A :
Basically, the changing of pad area does not alter its effectiveness. Brake effectiveness = Brake pressure *Cylinder area* is expressed by a coefficient of friction. However, the pad surface pressure may rise and the friction coefficient may lower if the pad area is decreased. In addition, decreased pad area results in adverse effects to occur such as brake fade, corrosion, etc. Therefore, it is not recommended since front and rear balance changing also tends to quicken change of brake pads.