2015-2019 Subaru Outback Front vs Rear Brakes: What Wears First and What to Replace

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2015-2019 Subaru Outback the front brakes almost always wear out first, because the front axle does most of the stopping work. The rear brakes last longer, but they carry the electronic parking brake, so a rear brake job on this generation needs more care than a basic pad swap. Replace pads and rotors as an axle set, and inspect the other end every time you have the wheels off.

How the Brakes Are Laid Out on the 2015-2019 Outback

This is the fifth-generation Outback. When Subaru introduced it for 2015, the company said the 2.5i picked up the larger brakes that had been reserved for the 6-cylinder model, and that every trim moved to ventilated rear discs in place of the solid rear discs used before. So whether you drive a 2.5i or a 3.6R, you have four-wheel disc brakes with vented rotors at both ends.

The rear calipers also hold the parking brake. There is no hand lever or pedal on this car: the parking brake is electronic, and a Subaru dealer bulletin describes an electronic parking brake (EPB) adapter cord connector located at the rear brake disc on 2015-2018 Legacy, Outback and WRX models with automatic transmissions. That connector matters when you do a rear brake job, and we cover it below.

The brake system also does more than stop the car. Subaru's launch material explains that Active Torque Vectoring applies brake pressure to the inside front wheel in corners, X-MODE uses enhanced Vehicle Dynamics Control logic on slippery ground, and the Hill Holder keeps the car still until you press the accelerator. Those systems all work through the same pads and rotors, and most of their work happens at the front.

Why the Front Brakes Wear First

When you brake, weight shifts forward onto the front tires. The front brakes are sized to do the larger share of the stopping, so the front pads carry more heat and more friction on every stop. On a heavy all-wheel-drive wagon like the Outback, that gap is easy to see: the fronts usually need service well before the rears.

How far apart the two ends get depends on how and where you drive:

• Stop-and-go city driving wears the fronts fastest, because almost every stop is a front-biased stop from speed.
• Towing, roof loads and mountain descents add heat at both ends, but the fronts still take the most.
• Torque vectoring and stability control use the brakes in corners and on slick roads. On this car the torque vectoring work is aimed at the inside front wheel, which adds a little front wear.
• Rust-belt driving can flip the pattern. Rear calipers see lighter use, so their slide pins and pad abutments corrode and seize more easily. A seized rear slide pin can wear one rear pad down fast while the fronts still look fine.

That last point is why you cannot assume the rears are fine just because the fronts went first. Look at both ends every time.

Symptoms and How to Tell Which End Needs Work

Subaru fits disc brake pad wear indicators that make a warning noise when the pads are worn. The owner's manual says that if you hear a squeaking or scraping noise from the disc brakes while braking, you should have the car inspected right away. Here is how to narrow down which end it is coming from:

• Squeal that starts or changes when you press the pedal is the classic wear-indicator sound. Listen with the window down in a quiet parking lot and note whether it comes from in front of you or behind you.
• Grinding means the pad lining is gone and metal is touching the rotor. Stop driving on it; the rotor is being damaged with every stop.
• Steering-wheel shake under braking points to the front rotors. Uneven rotor thickness, often called warped rotors, shows up through the steering.
• Pulsation you feel in the seat or pedal but not the wheel often points to the rear rotors.
• A flashing brake warning light on an Outback with an electronic parking brake can mean an EPB fault rather than worn pads. Have it checked before you drive further.
• One wheel much hotter or dirtier than the other side after a drive usually means a sticking caliper or slide pin on that corner.

The most reliable check is simple: pull the wheels and measure the pad lining at the thinnest point, inner and outer pad, on both ends. Inner pads often wear faster than outer pads, and you cannot see them well through the wheel spokes.

What to Replace, and What to Replace With It

Brakes are always serviced in axle sets, left and right together, so both sides grip evenly. For the front axle, a pad-and-rotor kit is the cleanest fix, because new pads on old rotors often squeal or judder until they bed in, and many worn rotors are already too thin to resurface.

For 2015-2019 Outbacks we carry the 2015-2019 Subaru Outback front brake kit from Power Stop. It is a Z23 Evolution Sport kit, which pairs carbon-fiber ceramic pads with drilled and slotted rotors. Power Stop describes the compound as a low-dust ceramic formula and ships the pads with dual-layer rubberized shims for noise control. The same front kit is listed to fit 2015-2021 WRX, 2015-2017 Legacy and 2006-2014 Tribeca, which reflects how Subaru shares front brake hardware across these platforms. The kit includes stainless hardware, a new pin bushing kit and high-temperature brake lubricant, so you are not reusing tired clips.

Also replace or service these at the same time:

• Abutment clips and slide pins. Clean the caliper brackets down to bare metal, lubricate the slide pins with a brake-rated lubricant, and replace torn pin boots. See our brake hardware kits.
• Brake fluid. Brake fluid absorbs moisture over time. Subaru recalled certain 2015 Outback and Legacy models because brake fluid with excess moisture could affect how the electronic stability control system performs; the fix was a fluid flush. That is a good reminder that old fluid is not only a pedal-feel issue on this car.
• Calipers if a piston is seized, leaking, or a boot is torn. Replace them in pairs. Browse brake calipers.
• Rear pads and rotors if the rear lining is getting close to the wear indicator. Shop brake pads and brake rotors by vehicle.

How Hard Is the Job on Each End?

Front: a front pad and rotor job on this Outback is a straightforward bolt-on job for a home mechanic with a jack, stands, a torque wrench and basic hand tools. Tighten the caliper bracket bolts, caliper bolts and lug nuts to the values in the factory service manual, not by feel.

Rear: the rear is where people get into trouble. Because the parking brake is electronic and works at the rear brakes, do not simply clamp the rear piston back like an older car. Put the electronic parking brake into its service or maintenance mode, by scan tool or the procedure in the service manual, before you retract the pistons, and follow the factory steps to return it to normal operation afterward. Forcing the piston can damage the parking brake mechanism.

Be gentle with the EPB wiring too. Subaru extended warranty coverage for a cracked lock tab on the EPB adapter cord connector at the rear brake disc on certain 2015-2018 Legacy, Outback and WRX models with automatic transmissions, to 15 years with unlimited mileage. The repair attaches a retaining clip so the connector cannot disconnect. If you find a cracked tab during a brake job, ask a Subaru retailer whether your VIN is covered before you pay for it yourself.

After either job, bed in the new pads with a series of moderate stops from speed, and check the fluid level in the reservoir under the hood.

Frequently Asked Questions

Do the front brakes on a 2015-2019 Outback really wear faster than the rears?

Yes, in normal driving. Weight shifts to the front under braking, so the front pads do more work and wear first. The exception is a sticking rear caliper or slide pin, which can wear a rear pad very quickly.

Does the 2015-2019 Outback have rear drum brakes?

No. Subaru moved every trim of the 2015 Outback to ventilated rear disc brakes, and the electronic parking brake works at the rear brakes.

Can I push the rear caliper pistons back with a C-clamp?

Not before you put the electronic parking brake into service mode. Use a scan tool or the service manual procedure to retract the parking brake first, then compress the pistons. Skipping this step can damage the EPB.

Should I replace rotors every time I replace pads?

Not always, but often. If the rotors are below minimum thickness, grooved, or causing a pulsation, replace them. A pad-and-rotor kit also gives the new pads a fresh surface to bed into, which cuts down on noise.

What is the squeak from my Outback brakes?

Subaru fits disc brake pad wear indicators that squeak or scrape when the pads are worn. Subaru's owner's manual says to have the brakes inspected immediately if you hear that noise.

Is my 2015 Outback affected by a brake-related recall?

Certain 2015 Outback and Legacy models were recalled for brake fluid with excess moisture that could affect stability control, remedied with a free fluid flush. Enter your VIN on nhtsa.gov to see open recalls for your car.

Sources

1. Subaru U.S. Media Center - 2015 Subaru Outback Press Kit - larger brakes on 2.5i, ventilated rear discs on all models, Active Torque Vectoring, X-MODE, Hill Holder
2. Subaru of America EPB Connector Tab Warranty Extension (NHTSA file) - EPB adapter cord connector at the rear brake disc, 2015-2018 models, 15-year extension
3. NHTSA recalls for the 2015 Subaru Outback - brake fluid moisture ESC recall and its remedy
4. Subaru owner's manual - Disc brake pad wear warning indicators - audible wear indicators and inspection advice
5. Power Stop - Z23 Evolution Sport - carbon-fiber ceramic, low-dust compound, rubberized shims, drilled and slotted rotors
6. Power Stop Z23 front kit fitment listing - 2015-2019 Outback fitment, shared WRX/Legacy/Tribeca fitment, included hardware