Back brake rotors, rotor,brake kit, brakes, machined rotors, resurface rotor, PowerStop

If you just had your brake rotors cut or machined and installed them with new pads but you hear a rhythmic thumping sound, it’s likely a rough finish on the rotor. The rough finish on the rotor acts like a screw to draw up the pads. The thump comes when the pads snap back to their original position.

Rotor finish is critical for proper brake operation. If your rotors look like an old vinyl record, you can try to sand the rotor surface with 180 grit sandpaper to remove any ridges that grab at your pads. You may have to re-machine or cut them at a very slow speed.

It is likely that a new set will cost less and save you time. PowerStop’s rotors come with a beautiful non-directional cross-cut finish that will perform well with those new pads.

What Causes Rotors to Make a Thumping Sound?

Thumping noises are somewhat common, and often caused by worn, grooved brake rotors. New rotors start out smooth and even, but like many of a vehicle’s parts and components, they eventually wear down over time. When brake pads press onto a rough, uneven surface, your braking and steering will feel rough, as well.

If your vehicle wobbles more than it thumps – and it only occurs intermittently or at certain speeds – your vehicle’s suspension may be the culprit, not the rotors. An auto technician can help you determine the root of your problem and address the issue.

How Long Do Brake Rotors Last?

Braking systems comprise three primary elements: rotors, calipers, and brake pads. A rotor is essentially a metal wheel inside your tire that is attached to the overall brake system. Calipers squeeze the rotor, causing friction that slows the vehicle to a stop. Brake pads attach to the calipers to prevent them from directly scraping the rotor.

The exact number of miles when you should replace brake components will vary, depending on your vehicle, parts, driving style, and even the locations and roads where you drive. It’s best to bring your vehicle in for regular maintenance and pay attention to any sign that may indicate an issue with your braking system.

Benefits of Replacing Rotors Instead of Machining Them

Rotors are machined to restore a smooth, flat surface by removing layers of material. When rotors are smooth and flat, they provide the necessary friction to allow maximum pad contact. Smooth rotors also reduce vibrations that can cause noise. 

In many cases, it may be in your best interest to replace worn rotors rather than machine them. Below are some benefits of replacing worn rotors with new ones instead of machining them.

Better Value in Less Time

It may be less expensive to simply replace worn rotors with new ones than it is to machine them. When rotors are resurfaced, it is important to machine the full set to prevent an imbalance. Machining rotors is a time-consuming process that could require multiple hours at the repair shop. This could make getting new rotors faster and less expensive.

Premium Quality

It is not uncommon for repair shops to resurface rotors as quickly as possible. Hurried work can lead to errors and possibly result in the removal of too much metal during the process. Trimming too much metal off the rotors can cause vibrations when driving. By replacing your rotors instead of machining them, you know that your rotors are in premium condition.

Peak Rotor Thickness

You can notice a problem when driving or braking when there is only a .001-inch difference in rotor thickness. If rotor weight is not evenly distributed, the imbalance can damage brake parts and cause your vehicle to shake, vibrate, or shift weight. Because of this, it is often a good idea to replace your rotors to ensure even and balanced rotor thickness.

Not Every Shop Machines Rotors

It is increasingly more difficult to find shops that will machine rotors anymore. If you do manage to find a shop that machines rotors, it may not be in your area or close to you. This is another reason why it may be beneficial to simply purchase new rotors rather than going through the hassle of finding a business that will machine them.

Safety You Can Rely On

If a problem with your rotors causes your vehicle to shake or a brake part to fail, it puts your safety and that of others on the road at risk. When you choose to replace rotors instead of machining them, you can rest assured that you are driving with safety you can rely on.

PowerStop offers high-quality performance brake kits and rotors that you can replace yourself or bring to a reliable repair shop. 

Need help finding a reliable shop near you? You can find one easily with PowerStop’s “Find an Installer” map.

Have a Question? PowerStop Can Help!

At PowerStop, our mission is to provide top-quality performance brakes for every vehicle on the road. If you have a question regarding any of our products, contact us today online or toll-free at (888) 863-4415. Our customer service team is available to answer your questions Monday through Friday from 8 a.m. to 5 p.m. (CST). Se habla español.


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