🔧 WRX - Rear Brake Pads & Rotor Replacement

You’ll remove the rear wheels, take off the rear brake caliper and bracket, swap the rotor, then install new pads and reassemble with correct torque. On your WRX, the parking brake is a small drum brake inside the rotor “hat,” so the parking brake must be fully released before rotor removal.

Difficulty Level: Intermediate | Estimated Time: 2-4 hours

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⚠️ Safety & Precautions

• ⚠️ Work on level ground and support the car with jack stands—never rely on a jack alone.
• ⚠️ Keep the transmission in 1st gear (or Reverse) with the engine off while lifting; release the parking brake only after the front wheels are chocked.
• ⚠️ Brake dust is unhealthy—use brake cleaner, not compressed air.
• ⚠️ Do not let the brake caliper hang by the brake hose; support it with a hook/strap.
• ⚠️ If brake fluid rises near the top of the reservoir when compressing pistons, remove a little fluid safely.

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🔧 Required Tools

You'll need the following tools for this repair:

• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• 19mm socket
• 1/2" drive breaker bar
• 1/2" drive torque wrench (20–150 ft-lbs)
• 3/8" drive ratchet
• 14mm socket
• 17mm socket
• 10mm wrench
• Flathead screwdriver
• C-clamp (6-inch)
• Wire brush
• Rubber mallet
• Pick tool
• Brake caliper hanger hook
• Brake cleaner spray
• High-temp silicone brake grease
• Anti-seize compound
• Shop towels
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Rear brake pad set - Qty: 1
• Rear brake rotors - Replace in pairs - Qty: 2
• Rear pad hardware/clip kit - Qty: 1
• Brake cleaner - Qty: 2 cans
• High-temp brake lubricant - Qty: 1

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📋 Before You Begin

• Park on flat ground, turn the engine off, and put the shifter in 1st gear (or Reverse).
• Chock both front wheels securely with wheel chocks.
• Fully release the parking brake lever.
• Open the hood and locate the brake fluid reservoir; you’ll check the level again after compressing the rear caliper pistons.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Loosen rear wheel lug nuts

• Use a 19mm socket and breaker bar to crack the lug nuts loose about 1/4 turn while the car is still on the ground.

Step 2: Lift and support the rear of the car

• Use the floor jack (rated 3-ton minimum) to lift the rear safely.
• Set the car onto jack stands (rated 3-ton minimum) at proper rear support points.
• Give the car a gentle shake to confirm it’s stable before you work.

Step 3: Remove the rear wheels

• Use the 19mm socket and 3/8" drive ratchet (or breaker bar) to remove the lug nuts, then remove both rear wheels.

Step 4: Remove the rear brake caliper (and support it)

• Locate the two caliper “slide pin” bolts (slide pins are the smooth guide posts the caliper moves on when you brake).
• Use a 14mm socket and 3/8" drive ratchet to remove the caliper slide pin bolts.
• Lift the caliper off the pads and hang it from the suspension spring using a brake caliper hanger hook.

Step 5: Remove the brake pads and hardware

• Pull the old pads out by hand; use a flathead screwdriver gently if they’re stuck.
• Remove the pad clips/hardware from the bracket (use a pick tool if needed).
• Spray the bracket areas with brake cleaner spray and wipe with shop towels.

Step 6: Remove the caliper bracket

• The “caliper bracket” is the heavy mount the pads sit in; it’s bolted to the knuckle.
• Use a 17mm socket and breaker bar to remove the two caliper bracket bolts.
• Set the bracket aside.

Step 7: Remove the old rotor

• Pull the rotor straight off the hub by hand.
• If it’s stuck, tap around the rotor hat with a rubber mallet to break rust loose.
• If it still won’t come off, the parking brake shoes may be lightly dragging inside the rotor:
  • Make sure the parking brake is fully released.
  • Use a flathead screwdriver through the rotor access slot (if aligned) to back off the parking brake star wheel adjuster a little at a time.

Step 8: Prep the hub and install the new rotor

• Use a wire brush to clean rust from the hub face so the new rotor sits flat (this helps prevent pedal pulsation).
• Apply a very thin film of anti-seize compound to the hub center ring only (avoid the wheel stud threads and rotor braking surface).
• Clean the new rotor braking surfaces with brake cleaner spray and shop towels.
• Slide the new rotor onto the hub.

Step 9: Reinstall the caliper bracket

• Position the bracket over the new rotor.
• Install the two bracket bolts by hand first, then tighten with a 17mm socket and breaker bar.
• Final tighten with a torque wrench: Torque to 80 Nm (59 ft-lbs).

Step 10: Service the slide pins and install new pad hardware

• Pull the slide pins out of the bracket (use your hands; use a pick tool gently if the boots stick).
• Wipe old grease off with shop towels, then apply high-temp silicone brake grease and reinstall the pins so they move smoothly.
• Install the new pad clips/hardware onto the bracket.
• Grease pins only, not pad friction material.

Step 11: Install the new brake pads

• Install the new pads into the bracket.
• Apply a thin layer of high-temp silicone brake grease to pad “ears” (the metal ends that touch the clips) if your pad maker recommends it.

Step 12: Compress the rear caliper piston

• Place an old pad against the caliper piston face to spread force evenly.
• Use a C-clamp (6-inch) to slowly push the piston straight back into the caliper until it bottoms out.
• Check the brake fluid reservoir level under the hood; do not let it overflow.

Step 13: Reinstall the caliper

• Set the caliper over the new pads and align the slide pin bolt holes.
• Install the slide pin bolts by hand first, then tighten with a 14mm socket and 3/8" drive ratchet.
• Final tighten with a torque wrench: Torque to 27 Nm (20 ft-lbs).

Step 14: Repeat on the other rear side

• Repeat Steps 4–13 on the opposite rear wheel.

Step 15: Reinstall wheels and torque lug nuts

• Reinstall both rear wheels and hand-tighten lug nuts.
• Lower the car off the jack stands using the floor jack.
• Torque lug nuts in a star pattern using a torque wrench: Torque to 120 Nm (88.5 ft-lbs).

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✅ After Repair

• Before driving, press the brake pedal slowly 10–15 times until it feels firm (this seats the pistons against the new pads).
• With the engine running, hold the brake pedal and confirm it stays firm and doesn’t sink.
• Check brake fluid level and top off only if needed (use the correct DOT brake fluid shown on the reservoir cap).
• Test drive at low speed first; confirm no grinding, pulling, or warning lights.
• Pad bedding (recommended): make 6–10 moderate stops from ~40 mph to ~10 mph, letting brakes cool a bit between stops; avoid holding the pedal hard while stopped right after.
• If the rotor was stuck and you adjusted the parking brake star wheel, confirm the parking brake holds properly and releases fully.

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💰 DIY vs Shop Cost

Shop Cost: $450-$850 (parts + labor)

DIY Cost: $180-$450 (parts only)

You Save: $270-$400 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-3 hours.

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