2013 Subaru BRZ Brake Noise: Squeal, Grinding and Pulsation Causes

By Core Brake Parts Tech Team — Circleville, OH warehouse

Most brake noise on a 2013 Subaru BRZ comes from one of three things: a pad wear indicator telling you the pads are nearly done (squeal), friction material worn through to the steel backing (grinding), or uneven rotor thickness (pulsation you feel in the pedal). A quick wheel-off inspection sorts out which one you have, and the fix is usually pads, rotors and fresh hardware rather than anything deeper in the system.

How the 2013 BRZ Brake System Is Built

Subaru's published 2013 BRZ specifications list power-assisted four-wheel disc brakes with a 4-channel, 4-sensor ABS, Electronic Brake-force Distribution and Brake Assist. Both axles use ventilated rotors, which matters when you diagnose noise: there are no rear drums on this car, so a rear scrape or squeal is coming from a disc, pad or caliper, not from shoes.

Because the BRZ is a light rear-drive sports car, a lot of owners run it hard on back roads, autocross or track days. That usage pattern drives many of the noise complaints below: heat glazes pads, aggressive compounds get installed for the track and then left on for the commute, and hot spots build up on the rotors.

It is also worth knowing that NHTSA's recall list for the 2013 BRZ shows two campaigns, 18V772000 (engine valve springs) and 12V254000 (owner's manual airbag wording). Neither involves the brakes, so brake noise on this car is a wear and maintenance issue, not a known factory defect.

Squeal: What It Means and How to Diagnose It

A high-pitched squeal is the most common complaint, and it has several possible sources. Work through them in order.

• Wear indicator contact. Many pads carry a small steel tab that touches the rotor when the pad is getting thin. Power Stop describes this happening at roughly 1/8 to 1/4 inch of remaining material. If the squeal is steady while driving and changes or stops when you press the pedal, look at pad thickness first.
• Tired or missing hardware. Anti-rattle clips and springs lose tension from heat cycles. Wagner's technical guidance notes that vibration is the main source of brake noise, and loose, rusty or weakened parts are what let the pad vibrate.
• Dry contact points. Caliper slide pins and the pad backing-plate contact points need the right lubricant. Dry pins also let the pad sit crooked, which leads to uneven wear and more noise.
• Glazing. Repeated hard stops from speed can overheat pads and rotors until the surfaces turn glassy. Glazed brakes squeal and lose bite, and a spirited-driving car like the BRZ is a prime candidate.
• Surface rust. A short squeal on the first few stops after the car sits overnight, especially in damp weather, is usually the pads wiping flash rust off the rotor. If it disappears after a few stops, it is normal.

Pull the wheels and check each pad against the rotor. Look for a shiny, glassy pad surface, blue or dark heat marks on the rotor, a pad shim that has shifted, and clips that no longer spring back. Compare inner and outer pads: a big difference points to a sticking slide pin or piston.

Grinding: Stop and Inspect Now

Grinding is a different sound, a low, harsh scrape that you often feel through the pedal. On a BRZ it usually means one of these:

• Metal on metal. The friction material is gone and the steel backing plate is cutting into the rotor. This is the most serious case: it ruins the rotor quickly and reduces stopping power. Park the car until it is fixed.
• Debris between pad and rotor. A small stone trapped behind the rotor splash shield or in the caliper makes a grinding or scraping noise that may come and go. It can score the rotor if left alone.
• Race pads on the street. Track compounds are built to work hot. Hawk lists its DTC-70 compound, for example, with a 400 to 1,600 F operating range and an optimal range of 800 to 1,200 F. Driven cold on the street, a pad like that tends to be noisy and hard on rotors. If a previous owner left track pads on, that alone can explain the noise.

If you see a groove cut into the rotor face, or a pad with little or no friction material, plan on pads and rotors on that axle, not pads alone.

Pulsation and Vibration: Rotor Thickness, Runout and Deposits

A pulsing brake pedal or a steering-wheel shimmy during braking is usually a rotor problem. The rotor face has developed uneven thickness, often from pad material deposited unevenly after a hard stop where the car sat with the brakes clamped on hot rotors. Wagner also points to excessive rotor runout and corrosion on the hub contact surface as sources of vibration.

How to narrow it down:

1. If the steering wheel shakes, suspect the front rotors. If the seat or whole car shudders, check the rear as well.
2. Clean the hub face and rotor hat before measuring. Rust between the hub and rotor can create runout on a perfectly good rotor.
3. Measure runout with a dial indicator and thickness at several points with a micrometer, and compare both to the limits in the factory service manual.
4. Tighten lug nuts in a star pattern with a torque wrench to the factory value. Uneven impact-gun torque can distort how the rotor sits on the hub.

Rotors that are under the minimum thickness stamped on them, cracked, or badly heat-spotted should be replaced rather than machined.

The Fix: Which Parts to Replace on a BRZ

Match the part to the problem and to how you drive the car.

For a daily-driven BRZ, a quality street pad is the right call. Browse our ceramic brake pads for a quiet, low-dust choice, or the full range of brake pads and replacement brake rotors. Street performance compounds such as Hawk's HPS 5.0 (part HB711B.661 for the front of the BRZ) are designed to add bite while staying street friendly. If you do track days, a dedicated race pad like the Hawk DTC-70 front race pads for the 2013 BRZ belongs on the car for the event, then back to street pads for the drive home. Hawk notes its compounds are for iron rotors, not carbon ceramic.

What to Replace at the Same Time and How Hard the Job Is

• Hardware: New pad clips and anti-rattle springs are cheap insurance against squeal. See our brake hardware kits.
• Slide pins and boots: Clean, inspect and re-lube. Replace torn boots.
• Brake fluid: Hard driving heats the fluid. Use the DOT type printed on the reservoir cap and flush it on the factory schedule, more often if you track the car.
• Rotors: Replace in axle pairs whenever they are under spec, grooved or pulsing.

On the BRZ this is a straightforward bolt-on job for someone with basic tools, a jack and stands, and a torque wrench. Plan an hour or two per axle. After installation, bed the pads in. Wagner's burnishing procedure calls for 20 slow-downs from 50 mph to 20 mph with light pedal pressure and about 30 seconds between each, which lays down an even transfer layer and helps prevent both noise and vibration. Follow the pad maker's own bed-in instructions where they differ.

Frequently Asked Questions

Are 2013 Subaru BRZ rear brakes discs or drums?

Discs. Subaru's 2013 spec sheet lists 290 mm ventilated rear rotors with single-piston calipers, and 294 mm ventilated rotors with dual-piston calipers up front.

Is there a brake recall on the 2013 BRZ?

NHTSA lists two recalls for the 2013 BRZ, one for engine valve springs and one for owner's manual airbag wording. Neither covers the brakes. Always run your own VIN on nhtsa.gov to confirm.

Why do my new BRZ brakes squeak?

The most common reasons are skipped or incomplete bedding, reused worn clips, missing lubricant on contact points, or a performance or race compound that is noisy when cold. Re-check the hardware and repeat the bed-in procedure.

Can I drive with grinding brakes?

Only as far as a safe place to park. Grinding usually means the pad backing plate is hitting the rotor, which reduces braking and destroys the rotor quickly.

Should I resurface or replace pulsing rotors?

If the rotor would end up below the minimum thickness marked on it, or has cracks or heat spots, replace it. Given the labor involved, many owners replace rotors in pairs with new pads.

Sources

1. Subaru Canada - 2013 BRZ Specifications - rotor sizes, caliper types, ABS/EBD/Brake Assist, tire size
2. NHTSA - 2013 Subaru BRZ recalls - recalls 18V772000 and 12V254000, none brake related
3. Wagner Brake - Brake System Noise - vibration causes, hardware, hub corrosion, runout, burnishing procedure
4. Power Stop - Causes and Solutions for Squealing Brake Pads - wear indicator at 1/8 to 1/4 inch, glazing, lubrication, bedding
5. Hawk Performance - DTC-70 - race compound operating and optimal temperature ranges, iron rotors only
6. Hawk Performance - HPS 5.0 HB711B.661 - street compound fitment for BRZ front