The discs and the pads are parts of the brake system that are going to wear out one hundred percent, so it is essential to check them from time to time and change them when necessary.
The first thing we have to know what the brake discs are, before changing them. And as its name suggests, they are discs, which are usually made of iron, which rotate together with the wheel. When we step on the brake, the brake calipers close, squeezing the wheel to slow down the car.
Now that we know what the brake discs are, we will see when to change them and to know when to change them we have to know that it varies depending on the type of use and driving. But, in general, it is recommended to change the brake discs for every time we change the pads twice, that is, every 80,000 miles. The best thing is to delay its replacement, since if they break we will run out of brakes causing an accident.
We also know how much it costs to change the brake discs, which is usually between 200 and 360 dollars, depending on the car model.
We also have to know if they fail, since they can break before their time and we don't want that, so we can identify it before it breaks. If, when you brake, you notice vibration in the pedal and you feel in the steering wheel, it is because the discs are loose and need a change. Also, you can see their status visually: if you notice something protruding between the braking surface and the edge of the disc, it's time to change them.
To understand the brakes we must also know the brake pads. These are inside the brake calipers, the pads rub against the brake discs to slow down the car when you step on the brake pedal.
To know when we should change the brake pads, we have to know that it depends on the type of use you give the car and your aggressiveness at the wheel. On average, the front pads are changed every 60,000 miles and the rear ones every 80,000 miles.
Also know that the brake pads already mounted, are usually worth between 100 and 250 dollars depending on the model of the car.
About how often to change them, we will see that almost all workshops will recommend that you change the pads if they are less than 30% thick, although they can be rushed more. The way to know how much pill is left is by looking. Through the spokes of the rim, you can see how much they have left. If your car does not have spoked wheels, you will have to remove the wheel to see the pads. If you see that there is less than 3 mm of pad left, you will have to change them.
To find out if they are failing, we will have to see if you hear a screeching noise when braking, or if your car lights up the pad wear warning light, replace them immediately.
And if we delay the change, and let the pads wear out completely, you will damage the surface of the discs. You could even damage the piston.