What are the ways to detect whether the brake pads are failing?

What are the ways to detect whether the brake pads are failing?
Nowadays, cars are not only simple tools, but also intimate companions in people's lives. Traveling has always been our desire for peace, and brake pads are one of the important components of safety, however, running brake checks, 4S shops seem a little bit every day Impractical, time consuming and expensive, is there any easy way to detect brake pads?
Look at the feeling that we can't be cold, if there is such a feeling, it may be because of the soft pad, which becomes thinner, which leads to the impact of the braking effect. At this moment, we need a deeper brake pedal to achieve the original feather braking effect. At this point On, you will need to check if you need to change the pads, check if it is lowered, the brake fluid has deteriorated and failed?
With the passage of time and habitual use, different brake pads will gradually become thinner due to the constant friction thickness. When the thickness of the brake pads we see with the naked eye is only about 1/3 of the thickness, the owner's friend needs to increase Self-inspection frequency, ready to replace at any time. Of course, some models cannot be seen directly with the naked eye, because the hub design requires professional disassembly of the tire to see it.
If the owner's friend has the sound of "iron rubbing against iron" when braking lightly, don't be careless at this time, the brake pads must be replaced immediately. The moving disc is damaged, and the noise cannot be eliminated by simply replacing the brake pads. Replace the brake disc if necessary.