2017-2023 Subaru Crosstrek Brake Caliper Problems and Replacement

By Core Brake Parts Tech Team — Circleville, OH warehouse

Most caliper trouble on the 2017-2023 Subaru Crosstrek is not a failed caliper at all. It is a slide pin or pad clip that has corroded and stopped letting the pads move, which causes dragging, pulling, heat and uneven pad wear. Subaru addressed the pad clip side of this in a service bulletin, and separately ran a service program on 2018 Crosstrek brake hoses that could swell. A caliper only needs replacing when the piston is seized, the piston seal leaks, or the body or bleeder is damaged.

How the Crosstrek Caliper System Works

The Crosstrek service manual lists a floating two-piston caliper up front and a floating single-piston caliper at the rear, both on disc brakes. "Floating" means the caliper body slides on two guide pins mounted in a support bracket. When you press the pedal, the pistons push the inner pad into the rotor and the caliper body slides inward to pull the outer pad against the other face. That sliding is what goes wrong most often.

The rear brake also carries a small drum-style parking brake inside the rotor hat, with its own primary and secondary shoes and an adjuster, so the rear caliper itself does not do the parking brake job. The manual specifies brake fluid meeting FMVSS No. 116 DOT3 or DOT4. Confirm your exact parts by VIN, since specifications can differ by trim and market.

Symptoms of a Caliper Problem

• Pull to one side under braking - one caliper is not clamping as hard as the other, or one is dragging.
• One wheel much hotter than the others after a drive, often with a burning smell - a dragging pad.
• Uneven pad wear - the inner pad worn much thinner than the outer, or one side of the car worn far more than the other.
• Squeal, grinding or a light rubbing sound that does not go away when you release the brake.
• Brake fluid on the inside of the wheel or tire - a leaking piston seal, bleeder or hose banjo fitting.
• Soft or sinking pedal - external leak or air in the system; check the reservoir level.

A quick check: with the car safely on stands and the wheel off, the caliper body should slide on its pins under hand pressure. If a pin will not move, moves in jerks, or springs back, it needs service.

Common Causes on the Crosstrek

Corrosion at the pad clips

Subaru bulletin 06-68-19 (revised as 06-68-19R) applies to all Crosstrek models and every Subaru that uses upper and lower pad clips. It added a step to the pad installation procedure: apply brake grease between the caliper support and the pad clips. Subaru states the reason directly - without it, corrosion builds up under the clips and the pad drags, causing uneven or premature wear of the new pads. The grease called out is Molykote AS-880N (Subaru part K0777YA010) or the equivalent supplied with the pad kit. In salted-road states this is the most common cause of a Crosstrek brake sticking after a pad job.

Seized or dry guide pins

Brake trade technicians list bent or binding mounting pins, worn slides, swollen or hardened guide seals and missing lubricant as the reasons a floating caliper stops moving freely. The result is the same as a stuck clip: uneven wear, heat and noise. A torn pin boot lets water in and the pin rusts in its bore.

Swelling brake hoses (2018 Crosstrek)

Subaru service program WUR-03R covers 2018 Crosstrek models built from May 9, 2017 to March 21, 2018, plus 2017-2018 Impreza. Brake fluid could squeeze between the hose inner and outer layers and make it swell. The remedy is replacing all four brake hoses. A swollen hose can hold pressure on a caliper, which looks exactly like a stuck caliper. If you own a 2018, have a Subaru retailer run your VIN for this program before buying a caliper.

Piston seal and piston corrosion

Old, moisture-laden fluid corrodes the piston and bore. The piston then retracts poorly or seizes. This is the case where the caliper itself is the fix.

The Fix: Service or Replace?

For replacement units, browse our brake calipers. If the pins and clips are the issue, a brake hardware kit with new clips and pin boots is usually all you need.

What to Replace at the Same Time

• Pads - a dragging caliper has usually glazed or tapered its pads. Replace pads on both sides of the axle, for example these 2017-2023 Crosstrek and Impreza front ceramic brake pads, or see all brake pads.
• Rotors - measure them. Front rotors below 22 mm or rear rotors below 8.5 mm, or runout over 0.05 mm, are done. Heat from a dragging caliper often leaves them uneven. See brake rotors.
• Calipers in pairs - replace both on an axle so braking force stays balanced side to side.
• Hoses - if a hose is cracked, swollen or the car falls under WUR-03R, see brake hoses. The bulletin notes the caliper banjo bolt sealing washers must always be new, never stacked on the old ones.
• Brake fluid - bleed with fresh DOT3 or DOT4 after opening the system.

How Hard Is the Job?

Caliper replacement on the Crosstrek is a moderate driveway job for someone who has done pads before. You remove the banjo bolt and the caliper or support bolts, swap the caliper, fit new sealing washers, and bleed the system. The Subaru hose bulletin lists 26 Nm for the caliper banjo bolts and 8 Nm for the bleeder screws; torque the caliper and support bolts to the values in the factory service manual. The same bulletin warns that if the reservoir drops below MIN during the work, the master cylinder or the VDC hydraulic unit may need separate bleeding, which can mean a trip to a shop. Keep the reservoir topped up while the line is open to avoid that. Finish with a test drive and check that no wheel runs hot.

Frequently Asked Questions

Is there a brake caliper recall on the Subaru Crosstrek?

The 2018 Crosstrek brake action we found is a service program (WUR-03R) that replaces all four brake hoses on a range of 2018 models, not the calipers. Separately, bulletin 06-68-19R adds grease between the caliper support and pad clips. Run your VIN with a Subaru retailer or on NHTSA to see open campaigns.

Why does my Crosstrek brake pull after new pads?

Most often a pad is dragging on rusted clips, or a guide pin was not cleaned and lubricated. Check that each caliper slides freely and that grease was applied between the support and the clips.

Does the Crosstrek have rear disc or drum brakes?

Rear discs with a single-piston floating caliper. The parking brake is a small drum shoe set inside the rear rotor hat.

What brake fluid does a Crosstrek use?

The service manual specifies fluid meeting FMVSS No. 116 DOT3 or DOT4.

Can I just rebuild the caliper?

Seal kits exist, but if the piston or bore is pitted a rebuild will not last. A replacement caliper is the faster, more reliable fix for most owners.

Do I need to replace both calipers?

It is good practice to replace calipers in pairs on the same axle so both sides clamp evenly and the car does not pull.

Sources

1. Subaru Crosstrek Service Manual - Brake specifications - caliper type, piston sizes, rotor sizes and limits, pad limits, DOT3/DOT4 fluid
2. Subaru Crosstrek Service Manual - Brake components - guide pins, boots, pad clips, rear parking brake shoes
3. Subaru Service Program WUR-03R (NHTSA) - 2018 Crosstrek brake hose swelling, production range, banjo and bleeder torque
4. Subaru Service Bulletin 06-68-19R (NHTSA) - grease between caliper support and pad clips
5. Subaru Service Bulletin 06-68-19 (NHTSA) - original pad clip lubrication bulletin, all Crosstrek models
6. Brake and Front End - Binding mounting pins on slider calipers - causes and fixes for sticking floating calipers