Rick's Free Auto Repair Advice

How long brakes last on a car

How long brakes last depends on how you drive, the quality of the brakes and how you maintain them

Many car owners ask this question when their car is in for an oil change and they’re told their brakes are worn. They’re often surprised because they think worn brake always make noise. But worn brakes are inevitable and how long brake last is often predictable based on these factors

• Where you drive — stop and go city driving wears out them out faster than highway driving. Mountainous driving also wears them out faster.
• How you drive — do you drive fast and brake hard?
• What type of vehicle you own — newer vehicles equipped with automatic emergency braking (AEB) and stability control use the rear brakes more often than older vehicles without those safety features. More on that later.
• The quality of the pads and rotors — low quality pads and rotors wear out faster than high quality parts.
• The type of pads used — non-asbestos organic (NAO), ceramic and semi-metallic  pads wear differently from one another
• How much cargo you carry and towing also affects how fast they wear.
• The condition of your shocks also affects how your fast they wear

Let’s start with some general rules

The general rule of thumb is about 40,000 miles

On vehicles without automatic emergency braking and electronic brake force distribution, you can usually expect about 40,000 miles from the fronts in mixed city/highway driving. If you do mostly highway driving, they’ll last as long as 70,000 miles. The rears last much longer since they’re only doing a portion of the braking and providing rear end stability. So they can last up to 80,000 miles in some cases.

Low quality parts dramatically reduce brake life

Many chain operated shops sell low quality brake parts and promote the fact that they come with a lifetime warranty. Don’t be fooled. Brakes are a wear item, so there’s no way any shop can offer a lifetime warranty unless there’s a catch. And there’s always a catch.

Here’s how it works. The cheap parts wear out within a year or two. The shop will be gracious and offer to replace the low quality pads for free. But you’ll have to pay for new rotors and the labor. A year or two from now, those cheap parts will wear out and you’ll have to pay again. See the pattern?

Low quality pads are made with thin low quality steel backing plates and cheap friction material. The thinner backing plates flex during high braking and that causes the friction material to crack. In addition, the low quality steel rusts, causing the friction material to de-bond from the plate and the pad falls apart. See the image below.

image showing rusted brake pad backing plate and broken friction material

High quality pads use premium friction materials and galvanized steel backing plates, so they last longer and resist rust.

Low quality rotors are thinner and don’t cool as well, shortening pad life

Low quality rotors are made with low quality cast iron, are thinner, and don’t use the carmaker’s cooling vane design. So they don’t cool as well and wear out the pads faster. See this post on the differences between cheap rotors and high quality rotors.

The greater the load, the shorter the brake life

This is kind of a no-brainer. If you carry lots of cargo or passengers or tow heavy loads, you’re going to wear out your brakes faster than the same vehicle with just a single passenger and no load.

The brake system works differently in vehicles equipped with AEB and stability control

Automatic emergency braking is designed to stop you quickly if the system senses you’re about to hit something. To stop you fast, these systems have electronic brake force distribution (EBD) that directs more pressure to the REAR calipers to prevent forward weight shift and reduce rear end lift. By reducing forward weight shift, the system reduces the weight on the front brakes so they can stop you more efficiently.

We’re seeing more instances of worn out rear pads wear while the fronts are still in good shape. That’s new and it’s caused by EBD. To learn more about EBD, see this article in Tire Review Magazine

©, 2017 Rick Muscoplat


Posted on by Rick Muscoplat

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