The video above is wrong on so many different levels. When checking your brakes, it’s imperative to know their exact use and where everything goes. Within the first minute of this video, the author, FreeStyleFlowFul, makes a costly mistake.

His mistake was very simple. The intended use of a slot in friction material is not for wear reduction but for noise reduction. 

Slots are often used when designing a brake pad. The manufacturer will “tune” the slot(s) so the pad makes less noise. Why? Slots change the natural frequency in which the pad oscillates. Noise is the result of high frequency vibrations between the pads, caliper and rotor.

The only true way to measure wear on a brake pad is to measure the height of the friction material starting at the backing plate.