When to replace brakes and rotors: A consumer’s Guide

Learn how long brakes last and when to replace your brakes and rotors

Replacing the brakes and rotors on your car is a crucial maintenance task that ensures your vehicle stops safely and effectively. Unfortunately, you won’t find a firm mileage in your owner’s maintenance guide telling you when to replace brakes. No carmaker can do that because brake wear is dependent on how you drive, whether you haul heavy loads, and your particular braking habits. However, I can give you some general guidelines for brake pad life, along with the common symptoms of brake issues.

When to replace brakes and rotors: A general guide

Front brake pads and rotors typically last about 40,000 miles, while the rear brake pads and rotors last around 70,000 miles. As I mentioned, how you drive, the loads you carry, and how you brake affect how long your brakes last. The factors below can prolong or reduce the 40,000 and 70,000-mile figures I just posted.

• The loads you carry dramatically affect how long your brakes last— Logically speaking, carrying heavier loads wears out your brakes faster than driving with a light load.
• How you drive—Hard braking wears out brakes faster than lighter braking
• Where you drive affects brake life— City stop-and-go driving wears out brakes faster than long stretches of highway driving. Driving in the mountains wears out brakes faster than driving on flat streets.
• Brake parts quality affects brake life— Low-quality brake pads and rotors wear out faster than high-quality brake parts

The six warning signs of brake problems

1) The red brake light is on— A brake warning light is serious. It can be the sign of a leaking fluid line, a leaking caliper or wheel cylinder, or a failed brake hose. Never ignore a brake warning light. Get it checked out immediately.

2) You notice a soft or spongy brake pedal— If your brake pedal feels soft or spongy when you press it, or if it sinks to the floor with little resistance, it’s a sign of a serious brake problem. This issue requires immediate attention as it can significantly reduce your ability to stop effectively.

3) You have reduced responsiveness— If your car isn’t stopping as quickly as it used to, or if you need to press the brake pedal further than normal to stop, this could indicate worn brake pads or a problem with your brake fluid.

4) You hear a squeal, screech, or squeak when you brake— If you notice a squeal, screech, or squeak as you apply the brakes, it’s time to have them checked out. Inspecting your brakes at the first sign of noise can often catch problems early and avoid accelerated brake wear that can cost you a bundle.

5) Your brakes grind— A seized component or worn-out brake pads often cause brake grinding. If you catch the problem early, the shop can often unseize the caliper or brake pad and save you the replacement cost.

6) The car shakes when you brake, or the brake pedal pulsates— For smooth braking, the brake disc (rotor) must rotate perfectly parallel to the wheel hub. Rust buildup on the wheel hub can cause lateral run-out, which causes the rotor to rotate in a wobble, which causes brake pedal pulsation. Get it checked out right away.

Brakes have changed since the old days— brake facts  you may not have known

Front brakes in older cars wear faster than rear brakes, but that’s not true on newer cars

On older vehicles without accident avoidance systems or electronic brake force distribution features, the front brakes perform almost 80% of the braking. So, the front brakes wear out long before the rear brakes. In those older vehicles, rear brakes can last twice as long as the front brakes.

However, on newer vehicles, brake wear is more evenly distributed

On vehicles equipped with accident avoidance systems (ADAS), automatic emergency braking (AEB), traction control, and stability control (TCS and ESC), the electronic brake force distribution (EBD) feature often applies the rear brakes first during hard braking events to reduce front-end noise dive and forward weight movement. This prevents the forward weight shift that can put high stress on the front tires, reducing their braking ability.

Due to the more equalized braking, shops perform rear brake jobs earlier on late-model cars and trucks.

Why worn brakes make a squealing noise

Car makers install metal wear indicators on the brake pads that come in contact with the rotor once the brake pad friction material wears down to a replacement level. The wear indicators are designed to contact the rotor once the friction material wears down to 1.5mm-2mm in thickness. Once the wear indicators touch the rotor, you’ll hear a high pitched squeal when you’re driving.

Brake pad wear indicators

©, 2015 Rick Muscoplat