Is It Your Brake Pads or Your Rotors? Here’s How to Tell

If you feel a steady pulsing in the brake pedal or the steering wheel while braking, it usually points to the rotors; if you hear high-pitched squealing or harsh grinding, it’s more likely the brake pads. A quick visual check of pad thickness (under 3 mm is worn) and rotor surface (deep grooves, blue heat spots, or heavy rust) can confirm which part needs attention.

What’s the Difference—and Why It Matters

Brake pads are the friction material that clamps down on the rotors (the metal discs) to slow the car. Pads wear down predictably and often include a built-in wear indicator that squeals when it’s time to replace them. Rotors don’t “wear out” in the same way, but their surfaces can become uneven, heat-spotted, or rust-pitted, leading to pedal pulsation and reduced braking performance. Despite the common phrase “warped rotors,” most issues are actually rotor thickness variation or pad material deposits, not literal bending. On hybrids and EVs, regenerative braking reduces pad use, so rotors can rust from lack of use—causing noise and uneven braking unless they’re periodically cleaned with a few firm stops.

Symptoms That Point to Pads vs. Rotors

The following list breaks down common sensations, sounds, and visual cues that help you distinguish pad-related problems from rotor-related ones, plus signs that suggest a different brake-system issue.

• Likely brake pads:
  – High-pitched squeal that starts mild and gets more consistent with speed, especially at low speeds; often the pad wear indicator.
  – Grinding or scraping noise that persists even with light brake pressure—usually pads worn down to metal backing plates.
  – Excessive brake dust on one wheel more than others.
  – Visibly thin friction material: less than about 3 mm (1/8 inch) means due for replacement.
• Likely rotors:
  – Pulse or vibration in the brake pedal during steady braking.
  – Steering wheel shake under braking (commonly front rotors); vibration felt more in the seat or floor can indicate rear rotors.
  – Visible deep grooves, heavy scoring, blue/purple heat spots, or a pronounced outer “lip.”
  – Rust pitting or uneven surface after sitting—especially common on EVs/hybrids that don’t use friction brakes much.
• Other brake-system issues (not strictly pads or rotors):
  – Pull to one side under braking (sticking caliper, hose issue, or uneven pad operation).
  – Soft or sinking pedal (air in system or hydraulic leak).
  – ABS or brake warning light illuminated (sensor/hydraulic/ABS fault).
  – Burning smell or very hot wheel after a short drive (dragging caliper).

Consider multiple symptoms together: for example, grinding plus heavy rotor scoring often means the pads are gone and the rotors are damaged—both typically need replacement.

Quick Driveway Checks You Can Do

These simple inspections can help confirm whether pads or rotors are at fault before you book service. Always park on level ground, set the parking brake, and be safe around moving parts.

1. Check pad thickness: Shine a flashlight through the caliper opening; if the friction material is under ~3 mm, replace pads soon.
2. Inspect the rotor surface: Look for deep grooves, blue heat spots, a heavy ridge on the edge, or heavy rust/pitting. Any of these can justify rotor service or replacement.
3. Spin and listen (wheel off the ground): With the car safely lifted, spin the wheel by hand. Consistent scraping can be normal light contact; rhythmic scraping or binding suggests rotor high spots or a dragging caliper.
4. Pedal feel test: With the engine off, pump the pedal until firm; if it slowly sinks, that’s hydraulic (not pad/rotor) trouble.
5. Wheel lug torque: If you recently had wheels off, uneven or over-torqued lug nuts can induce rotor runout. Proper, even torque in a star pattern can prevent pedal pulsation.

If what you see or feel is inconclusive, a shop can measure rotor runout and thickness with precision tools to diagnose definitively.

Test-Drive Cues by Speed

A careful road test can isolate the problem. Choose a safe, empty stretch and follow traffic laws.

• Low speed (5–15 mph): Intermittent squeal that changes with light brake pressure suggests pads; harsh grinding implies pads are gone and chewing the rotor.
• Moderate speeds (25–45 mph): A steady pedal pulse or vibration under light-to-moderate braking points to rotor thickness variation or runout. Steering wheel shake usually means front rotors; vibration through the seat/floor can indicate rears.
• Higher speeds (50–60 mph to 10–15 mph): If a few medium-firm stops smooth out light noise after rain or sitting, that was surface rust or glazing; persistent pulsation means rotor correction or replacement.
• Coasting (no brakes applied): Vibration when not braking is typically tires, wheels, or suspension, not brakes.

Repeat a test only if safe; overheating brakes during testing can create new pad deposits and muddy the diagnosis.

When to Stop Driving and Fix Immediately

Some brake symptoms signal urgent safety issues and can damage parts quickly if ignored.

• Metal-on-metal grinding.
• Brake pedal that’s soft, sinks, or goes to the floor.
• Brake or ABS warning lights illuminated.
• Strong pull to one side or burning smell from a wheel.

In these situations, arrange a tow or drive only the shortest safe distance to service.

Repair Choices: Pads Only, Rotors, or Both?

Whether you replace pads, rotors, or both depends on measurements and surface condition. The rotor’s minimum thickness is stamped on the hat; shops also check runout. Typical acceptable runout is around 0.002–0.004 in (0.05–0.10 mm).

• Pads only: Reasonable if rotors are smooth, within thickness spec, and there’s no pedal pulsation. Lightly deglaze rotors and bed the new pads properly.
• Rotors (and usually pads): Recommended if you have pulsation, heavy grooves, heat spots, significant rust pitting, or the pads reached metal. New rotors with old pads can cause poor bedding and noise.
• Resurface (machine) rotors: Viable if thickness allows and surfaces can be restored true. Many shops replace rotors instead, given cost and long-term results.

Always service brakes in axle pairs (both fronts or both rears), replace pad hardware, and follow a proper bed-in: typically 5–8 medium-hard stops from ~60 to ~10 mph without coming to a full stop, then allow cooling.

Costs and Time

U.S. typical ranges vary by vehicle: pads only often runs $100–300 per axle parts and labor; pads plus rotors commonly $250–600 per axle; performance or luxury models can be higher. Resurfacing may cost $20–40 per rotor if feasible. DIY saves labor but requires the right tools and procedures, including correct torque and service modes for electronic parking brakes.

Notes for EVs and Hybrids

Because regenerative braking reduces friction-brake use, rotors can rust and develop deposits. Do a few medium-firm stops weekly or monthly to keep rotors clean. Many EVs/hybrids have electronic parking brakes requiring a service mode before pad replacement; consult the service manual or a qualified shop.

Bottom Line

Pulsation under braking usually implicates the rotors; squealing or grinding points to the pads. A quick visual check—pads under 3 mm, rotors with grooves or heat spots—confirms the diagnosis. Address urgent symptoms immediately, service both sides of an axle together, and bed new parts properly for quiet, confident stops.

How do I know if I need new rotors or just brake pads?

You likely need new brake pads if you hear high-pitched squealing or your pedal feels soft; you likely need new rotors if you feel a pulsating or vibrating steering wheel, hear grinding, or see deep grooves, significant rust, or edges on the rotor surface. A professional inspection is recommended to accurately diagnose the issue and determine if both components need replacement. 
You can watch this video to see the difference between good and bad rotors: 59sMohawk ChevroletYouTube · Apr 7, 2023
Signs You May Need New Brake Pads

• High-pitched squeal: An annoying high-pitched noise that occurs when you apply the brakes often indicates that the brake pads are worn down and the wear indicator is making contact with the rotor. 
• Soft or spongy brake pedal: If your brake pedal feels like it travels closer to the floor or is less responsive than usual, it could be a sign of thin brake pads. 
• Visible thin pads: A quick visual inspection through your wheels may reveal that your brake pads are less than 1/4 inch thick. 

Signs You May Need New Rotors 

• Grinding or scraping noise: A low-pitched grinding or scraping sound when braking is a serious indicator that the rotors are damaged, warped, or the pads have worn down completely. 
• Pulsating or vibrating steering wheel: If you feel a vibration or pulsing in the steering wheel or brake pedal when you apply the brakes, it often means the rotors are warped. 
• Grooves, scores, or rust: A visual inspection of the rotor surface can reveal deep grooves, scoring marks, or excessive rust buildup, which can compromise braking performance. 
• Large edges: A noticeable lip or edge on the outer part of the rotor is a sign that the rotor has worn unevenly and needs replacement. 
• Vehicle pulling to one side: If your vehicle drifts to one side when you brake, it could be due to uneven rotor wear. 

This video explains how to check your brake pads and rotors: 59sBudget MechanicYouTube · Oct 11, 2022
When to Consider Replacing Both 

• Uneven pad wear: Opens in new tabIf one brake pad is worn unevenly, it can indicate a warped rotor, requiring both parts to be replaced.
• New pads on old rotors: Opens in new tabInstalling new brake pads on worn or damaged rotors can lead to improper pad wear and reduced braking performance, so it’s often best practice to replace them together.

Is it my brakes or my rotors?

Decreased Braking Performance
If your vehicle takes longer to come to a complete stop or if the brakes feel less responsive, it’s time to inspect the brake rotors. Reduced braking performance can result from worn-out or damaged rotors that need replacement.

What will bad brake pads feel like?

If the brake pads are worn out, the backing plate can contact the rotor and exhibit metal-on-metal grinding noises as well as a rough feeling in the brake pedal. Extended stopping distances. The friction material helps you slow down sooner, and worn-out brakes often aren’t as effective. Grooves in the rotor surface.

How to tell if a brake rotor is bad?

You can tell a brake rotor is bad by listening for squealing, grinding, or scraping noises during braking, feeling a pulsating brake pedal or a shaking steering wheel, observing the rotor for deep grooves, cracks, or rust buildup on its surface, or noticing increased stopping distances. A mechanic can also check for rotors that have become too thin or are glazed with blue or shiny spots.
 
This video demonstrates the differences between a good and a bad brake rotor: 59sMohawk ChevroletYouTube · Apr 7, 2023
Listen for Sounds

• Squealing or Squeaking: A high-pitched squeal when braking can indicate worn brake pads or warped rotors. 
• Grinding or Scraping: A metallic grinding or scraping noise, especially at lower speeds, suggests a severely worn rotor, potentially down to the metal. 

Feel for Vibrations 

• Pulsating Brake Pedal: Opens in new tabA continuous pulsing sensation through the brake pedal when you press it often signals a warped or distorted rotor. 
• Shaking Steering Wheel: Opens in new tabA shaking steering wheel when you brake is another sign that the rotors may be warped or unevenly worn. 

You can watch this video to see how to inspect your brake rotors for signs of warping: 1mExpertVillage Leaf GroupYouTube · Dec 14, 2020
Visually Inspect the Rotor 

• Deep Grooves or Scoring: Look for deep, visible grooves or score marks on the rotor’s surface, which indicates excessive wear. 
• Rust Buildup: While some surface rust is normal, excessive rust, especially on the inner surfaces of the rotor, can necessitate replacement. 
• Cracks: Look for any large cracks on the rotor’s surface, as these are a serious cause for concern and can lead to brake failure. 
• Blue or Shiny Spots (Glazing): Glazed rotors with blue or shiny spots indicate overheating and a compromised surface. 

Check Performance

• Increased Stopping Distance: Opens in new tabIf you have to press the brake pedal harder or for longer to stop your vehicle, it could be a sign of worn or bad rotors. 
• Reduced Braking Performance: Opens in new tabA general reduction in your vehicle’s braking effectiveness, especially during heavy or prolonged braking, can also point to rotor issues. 

This video explains 7 signs that your brake rotors are worn out: 59scar PROblemsYouTube · Jun 1, 2025
If you notice any of these signs, it’s best to have a mechanic inspect your brake rotors immediately to ensure your safety.