Brake discs vs. brake rotors - what's the difference?
There are two types of braking system commonly found on the cars we drive today.
The most common type uses discs, also known as brake rotors
, which turn with the wheel/tire. (We cleverly call these disc brakes.) The disc is straddled by a brake caliper
, whose pistons are pushed down with the pressure originating from the brake pedal which is transferred by the brake master cylinder
. The pistons press on the brake pads
, these clamp against the disc, and this, in turn, slows or stops the vehicle.
Another type of brake system uses brake drums
rather than disc rotors. Essentially brake work the same way as disc brakes but rather than having calipers and pads, drum brakes utilize a brake shoe
that squeezes outwards from the inside of the drum, thus causing the wheel to slow or stop. What to look for when visually inspecting your brakes
Making sure that you regularly inspect your brakes is a very important part of keeping your vehicle in good stopping order.
Remove the tires and wheels and visually inspect your brake pads
to ensure they’re still in good condition. Generally, there should be at least 1/4 inch of pad thickness left. If you see less than 1/4 inch of pad, it is probably time to change those pads, and probably the rotors along with them. You can tell if your rotors need to be replaced by feeling the flat surfaces, front and back, that the pads come into contact with, if this surface has groves, scratches or rust, they should be replaced. (Make sure the rotors are clean, dry and free of any oils or fingerprints you might have left behind.) Both the disc pads and the disc bake rotorbs are commonly replaced when doing a thorough brake job.
What to listen for when inspecting your brakes by sound
Another way to know you need to replace your brakes is by their sound. Have you ever heard a high-pitched screeching sound when you applied your brakes? That's a small metal shim, called an indicator, which is giving you an audible warning that you need to replace your brake pads. This sound is loud enough to be heard while the windows are up, but not necessarily loud enough to be heard over the radio or air conditioner. If you hear noise when braking, make plans to do a visual inspection as soon as possible.
In addition to maintaining the pads, rotors, drums and shoes, you may want to regularly check your brake fluid in the master cylinder, to make sure the brake fluid is at the appropriate level, and in good condition. If your brake fluid has a milky color, it could mean that water or condensation has infiltrated the fluid and you need to change the brake fluid. How does the brake system work?
The brake system uses hydraulics to transfer the pressure that you apply to the brake pedal out to components at each tire. These components then squeeze down, making the tire/wheel stop spinning, thus slowing the car down. The brake master cylinder
, brake hydraulic hoses
and brake hydraulic lines
are the lifeblood of the system and work to make sure the pressure from the brake pedal is transferred correctly and quickly out to each wheel.