The What, How & Why: Brakes Edition

Written by Jack Crowley, Jr. C&J Automotive Specialists

This article is going to deep-dive into one common car care need: Brakes! As you read this article, you’ll learn all about brakes and why keeping them maintained is so vitally important.

What are brakes?

We all know that brakes are what make your car stop. But brakes are more than just the things you commonly replace, like the pads and rotors. Brakes, or the brake system, go all the way from your brake pedal through a hydraulic system with pistons and brake fluid, through brake lines and hoses, to those final disc or drum brakes.

Jack Crowley, Jr.

How do brakes work?

Brakes work by pressing either the brake pad (in disc brakes) or the brake shoe (in drum brakes) into the disc (commonly known as a rotor) or the drum, respectively. Doing so creates a LOT of friction — enough to stop the car by converting the kinetic energy of a car in motion into heat.

Why do you need new brakes?

Over time, all that friction and heat will wear down those components, the pads and rotors or the shoes and drums. The pads and shoes will wear down more quickly than the rotors and drums. Without replacing what has gotten worn down, you won’t be able to stop as effectively as before, thus increasing your risk for injuring yourself and others.

Why do you need new brake fluid?

Brake fluid is the brake system’s hydraulic component that allows the pads and rotors to be applied effectively. Over time, brake fluid deteriorates, gets dirty and less effective.

How can you tell when you need new brakes?

You may feel like you have to push on the brake pedal harder, almost into the floor, to make your car stop normally. You may also hear your brakes constantly squeaking, squealing or grinding. A high-pitched scraping sound could be pad-wear indicators, literally sounding an alarm. And in some cases, a red brake warning light may light up on your dashboard!

What happens when my mechanic inspects my brakes?

Your mechanic will be able to identify the specific issue with your brakes. For example, while excessive brake pedal travel could mean worn pads, it could also be caused by low brake fluid.

Your mechanic will also measure the thickness of the pads and rotors and whether they’re evenly worn. Those measurements will then be compared with the manufacturer’s recommended guidelines. But generally, most shops will recommend new pads and rotors when only 20% of the original thickness remains (as new pads can range from about 3/8"to 1/2") or if the pad is worn down to 3/32 of an inch.