Generally speaking, the vehicle needs to replace a brake pad at about 50,000 kilometers.
Specific is to replace the front wheel or the rear wheel, according to the condition of the car.
As we all know, when the car brakes, because the center of gravity forward, the front wheel friction will be greater, so the front wheel brake pads play a major role in braking;
Especially for the front drive, or based on the front drive structure of the four-wheel-drive, the vehicle's front and rear weight is heavy and light, the front wheel brake braking force is the largest, theoretically the brake pad wear is also the largest.
Therefore, for most cars, the front brake pads may be replaced before the rear wheels.
But there are exceptions
For rear-drive vehicles, or four-wheel-drive vehicles based on rear-drive vehicles, the total weight ratio is close to 50:50, or even 40:60 for cars with middle or rear engines.
So it's not necessarily that the front wheels are bearing more friction than the rear wheels.
Especially when such vehicles are loaded with goods, the center of gravity moves back, but the rear wheels bear more friction.
As for the braking time, due to the body forward tilt caused by the center of gravity forward, this is correct in physics, but in practical operation, the vehicle is generally slow brake stop, big foot brake or sharp brake is not common, so the center of gravity forward to play a role is secondary.
The most critical, or the vehicle before and after the weight ratio.
For the front drive and the four-wheel drive based on the front drive, the front wheel friction is significantly greater than the rear wheel due to the front and rear weight ratio of 60:40 or even 70:30.
Not surprisingly, the brake pads of the front wheels will be replaced before the rear wheels.
Note that when the brake pads are changed, it is necessary to change a set of brake pads, not a single wheel. This is to ensure that the braking force of the left and right wheels is uniform.
So the question is, how to judge whether the brake pads need to be replaced?
First of all, most cars have a brake pad self - check function.
The relatively low method is through the thickness of the warning iron, that is, the brake pad wear to a certain thickness, generally 3mm thick, the need to replace the brake pad, the iron will cause friction with the brake disc, resulting in abnormal sound.
At this time, we must immediately replace the brake pads, otherwise it will damage the brake disc.
And the last 3mm thickness of the brake pad, is not the standard friction material, but the insulation layer and adhesive layer, the hardness is greater, will damage the brake disc.
On the more advanced cars, electronic detection is used.
A conductive metal block is embedded in the bottom of a thin groove in the middle of the brake pads for cooling.
If the brake pad is flush with the metal, it will cause the metal to rub against the brake disc, and the current in it will change, telling the on-board computer that the brake pad has reached a certain limit.
Therefore, the test method of brake pad is:
First, observe the brake disc there is no obvious ring scratch line, if there is, it is most likely to be a metal sheet or metal block of scratch;
Two, with a thickness ruler, or a dollar coin attached to the wire, homemade thickness ruler, to detect the width of the gap between the brake pad and the brake disc.
We recommend the second method, which can prevent it in advance.
For car lovers, it is the best choice to replace the brake pads in time before the alarm.
In addition to the above two methods, there is the observation method, which is to take a flashlight to shine on the brake pad to observe the thickness.
Turbo brother does not suggest this method, in fact, no effect, most owners of the thickness of the brake pad is no concept, take a flashlight also can not come to any conclusion.
Unless you're a repairman who has trained his eyes for years and can tell the difference at a glance.
Moreover, many cars' hub banners are more complex, and it is impossible to see the brake pads.