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2018 Enclave: Pulsating Brakes and Steering Wheel Shake at Speed

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Sarah K. · rep 0 · May 25, 2:45 AM · 1 replies · solved · Question

Vehicle: 2018 Buick Enclave Premium

Hey everyone, I've got a 2018 Buick Enclave Premium with about 65,000 miles on it. Lately, I've noticed a significant pulsation in the brake pedal, especially when braking from highway speeds. It's also accompanied by a noticeable shake in the steering wheel.

It feels like the front end is really vibrating when I hit the brakes hard. This problem has been getting progressively worse over the last couple of weeks. I had the pads and rotors replaced about 20,000 miles ago, so I'm a bit surprised to be having this issue again so soon.

Could this be warped rotors again, or is there something else I should be looking at? Any advice on what to check first would be greatly appreciated. Thanks!

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 25, 2:45 AM

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ClearTheCode admin answer:

Experiencing a pulsating brake pedal and steering wheel shake during braking, especially at highway speeds, is a common symptom that often points to issues within your braking system. Given your description, here's a breakdown of potential causes and steps to take:

  1. Warped Brake Rotors: This is the most common culprit. Rotors can warp due to excessive heat from heavy braking, or improper installation/torqueing of lug nuts. When warped, the rotor's surface isn't perfectly flat, causing the brake pads to grab unevenly, which you feel as a pulsation.
  2. Uneven Brake Pad Wear: While less common than warped rotors, uneven pad wear can contribute to a similar feel. This might indicate an issue with the brake caliper not applying even pressure.
  3. Sticking Brake Caliper: A caliper that isn't fully releasing can cause excessive heat buildup, leading to rotor warping, or it can cause uneven braking pressure.
  4. Wheel Bearing Issues: Though less likely to cause a primary pulsation during braking, a worn wheel bearing can contribute to vibrations and noise, especially at speed. However, the pulsation directly tied to braking strongly suggests a brake component issue.

What to do:

  • Step 1: Inspect Visually: Carefully examine your front brake rotors for any visible scoring, grooves, or discoloration (blue/purple spots indicate extreme heat). Check the brake pads for uneven wear.
  • Step 2: Measure Rotor Runout: A professional shop can measure the rotor's runout (how much it deviates from being perfectly flat) using a dial indicator. This is the definitive test for warped rotors.
  • Step 3: Check Caliper Operation: Ensure the calipers are sliding freely and the piston retracts properly. A sticking caliper needs to be serviced or replaced.
  • Step 4: Consider Replacement: If rotors are warped beyond specification, they should be replaced. Sometimes, turning (machining) rotors can fix minor warping, but replacement is often recommended for longevity and safety, especially if they've been turned before or are close to minimum thickness.

When to see a shop:

It's highly recommended to have a professional mechanic inspect your braking system promptly. Braking issues affect your vehicle's safety. They can accurately diagnose the problem, measure rotor runout, and ensure all components are functioning correctly. Do not delay, as compromised braking can lead to dangerous situations.

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