So I created this picture of a warped rotor. On the left, that’s what most people imagine a warped rotor to look like. On the right it is what a warped rotor actually looks like, like any other normal rotor. One way to know if a rotor is warped is to use caliper gauge to measure the thickness.
So for years my brake pedals were vibrating. For a better term, it would actually pulsate. My dad would always mention how it bothered him that my car’s brake pedals pulsated when he pressed on the brakes. I said that’s normal since its a SUV. The front brake rotors and brake pads were new at that time, rear rotors were Raybestos that were a few years old with Wagner brake pads so I assumed those couldn’t be the culprit because they were name brand products with a reputation for quality. So my father changed the brake booster thinking it was the culprit but the pedals still were pulsating when braking. Did it bother me? Not really, I assumed since it was a SUV and had all terrain tires that a rough ride was expected. Until one day I was driving a 2016 Camry and when I pressed on the brakes I realized how smooth it felt when it stopped. That’s when I realized that there was an issue with my brakes.
Upon researching people were blaming unbalanced tire for the brake vibration and someone else saying that brake rotors rarely ever warp but its just an uneven deposit of material. I did find a comment that mentioned that the only reason the brakes pulsate is because the brake pads will move in and out due to the warp in the rotor causing the fluid to pulsate back and forth. This sounded really reasonable but at the same time I doubted my brake rotors were warped because online people mentioned warping only happens when:
- Uneven torque on wheel lug nuts, but I always used a torque wrench to tighten my lug nuts to make sure the torque is consistent
- Cheap rotors made with poor quality material, but these rear rotors were made by Raybestos which is known for their quality.
- Uneven deposit of material so you have to even the material out by driving from 0 to 60 and then braking really fast, repeat 8 to 10 times. I tried it and my brake pedals was still vibrating/pulsating.
- The rotors were not warped but unbalanced tires is causing the vibration. With all terrain tires my entire car does vibrate a little. When braking my car doesn’t vibrate at low speeds but my brake pedals pulsate still.
So I decided to service my brakes and see if I notice any faults. I sanded down the pads to make it level, sanded down the glaze on the rotors, re-greased the calibers and bleed the brakes. That’s when I discovered a surprise. A warped rotor! So I was sanding one of the rear rotors and I noticed one side was sanding higher than another side.
This is the rear warped rotor on my Xterra
This is to highlight the high and low side.
This was the high side. The inside was flat with the rest of the rotor.
Here was the low side. There was a noticeable drop off. My nail actually dipped down running across it.
I didn’t have a specialized tool but it was noticeable when I ran my fingers across the low and high side. I decided switch it out with my OEM Nissan rotors that came with the Xterra and to my surprise the vibration actually stopped. No more pulsating in the brakes. Not as smooth as the Camry but a huge improvement!
So if your brakes do pulsate you might actually have a warped rotor that needs to be replaced.