🔧 GS - Rear Brake Pads & Rotor Replacement

You’ll remove the rear wheels, take off the rear calipers and brackets, replace the rotors and pads, then reassemble and bed-in the brakes. This restores stopping power and prevents noise/vibration from worn pads or warped rotors.

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

---

⚠️ Safety & Precautions

• 🛑 Work on level ground and support the car with jack stands before going under or removing wheels.
• 🛑 Do not press the brake pedal while a caliper is off the rotor (it can push the piston out and leak fluid).
• 🛑 Brakes get hot—let everything cool before starting.
• 🛑 If your GS has an electronic parking brake (EPB), you must retract it before compressing the rear caliper piston.
• 🛑 Avoid breathing brake dust—use brake cleaner, not compressed air.

---

🔧 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
• 21mm socket
• Breaker bar (1/2")
• Torque wrench (20-150 ft-lbs range)
• 14mm socket
• 17mm socket
• Ratchet (3/8" or 1/2")
• Socket extension (3"-6")
• Flathead screwdriver
• Bungee cord
• Brake caliper piston tool kit (specialty)
• Wire brush
• Rubber mallet
• Brake cleaner spray
• Shop towels
• Nitrile gloves
• Safety glasses
• OBD2 scan tool with EPB service function (specialty)

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Rear brake pad set - Qty: 1
• Rear brake rotors - Qty: 2
• Rear pad hardware/clip kit - Qty: 1
• Brake caliper grease (silicone) - Qty: 1
• Brake parts cleaner - Qty: 1
• DOT 3 brake fluid - Qty: 1 quart

---

📋 Before You Begin

• 🅿️ Park on level ground, set the parking brake, and place wheel chocks in front of the front tires.
• 🔓 Crack the rear lug nuts loose 1/4 turn using a 21mm socket and breaker bar before lifting.
• Assumption: This covers both EPB and non-EPB rear brake setups—follow the matching EPB step below.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Lift and secure the rear

• Use a floor jack (rated 3-ton minimum) to lift the rear at the correct jack point.
• Place jack stands (rated 3-ton minimum) under the rear support points and lower the car onto them.
• Confirm the car is stable before removing wheels.

Step 2: Remove the rear wheels

• Remove the lug nuts using a 21mm socket and ratchet.
• Remove both rear wheels and set them aside.

Step 3: Retract the parking brake (EPB only)

• If your GS has an electronic parking brake, connect an OBD2 scan tool with EPB service function (specialty).
• Use the scan tool to run the rear EPB into service/maintenance mode (retract).
• EPB forces the piston out—don’t fight it.

Step 4: Remove the rear caliper

• Turn the steering wheel slightly if needed for access, then locate the two caliper slide bolts.
• Remove the slide bolts using a 14mm socket and ratchet.
• Lift the caliper off the bracket and hang it from the suspension using a bungee cord (never let it dangle by the hose).

Step 5: Remove the old pads and hardware

• Pull the pads out of the bracket by hand (use a flathead screwdriver gently if they’re stuck).
• Remove the pad clips/hardware from the bracket.
• Clean the bracket pad “rails” using brake cleaner spray and a wire brush.

Step 6: Remove the caliper bracket

• Remove the two bracket bolts using a 17mm socket, breaker bar (1/2"), and socket extension (3"-6").
• Set the bracket aside.
• Torque on install: Torque to 98 Nm (72 ft-lbs)

Step 7: Remove the rotor

• Remove any rotor retaining clips (if present) using a flathead screwdriver.
• Pull the rotor off the hub. If it’s stuck, tap the rotor hat with a rubber mallet until it breaks free.
• Clean the hub face using brake cleaner spray and a wire brush so the new rotor sits flat.

Step 8: Install the new rotor

• Spray both sides of the new rotor with brake cleaner spray and wipe with shop towels (removes packing oil).
• Place the rotor onto the hub.
• To hold it flush while you work, thread on 1-2 lug nuts by hand temporarily (remove them before the wheel goes back on).

Step 9: Reinstall the caliper bracket and hardware

• Install the bracket bolts using a 17mm socket and ratchet.
• Torque: Torque to 98 Nm (72 ft-lbs)
• Install the new pad clips/hardware into the bracket.
• Apply a thin film of brake caliper grease (silicone) to the pad contact points on the clips only (not on the rotor).

Step 10: Compress the rear caliper piston

• Use a brake caliper piston tool kit (specialty) to push the piston back in slowly.
• A caliper piston tool is a tool that presses the piston straight back without damaging the boot.
• Watch the brake fluid level while compressing—if it gets too high, remove some fluid from the reservoir (do not spill on paint).

Step 11: Install the new pads and reinstall the caliper

• Install the new inner and outer pads into the bracket.
• Slide the caliper back over the pads.
• Install the caliper slide bolts using a 14mm socket and ratchet.
• Torque: Torque to 34 Nm (25 ft-lbs)

Step 12: Repeat on the other rear side

• Repeat Steps 4 through 11 on the other rear wheel.
• Do one side at a time to compare.

Step 13: Reinstall wheels and torque lug nuts

• Reinstall the wheels and hand-thread the lug nuts.
• Lower the car off the jack stands using the floor jack (rated 3-ton minimum).
• Tighten lug nuts in a star pattern using a torque wrench (20-150 ft-lbs range).
• Torque: Torque to 103 Nm (76 ft-lbs)

Step 14: Exit EPB service mode (EPB only)

• Use the OBD2 scan tool with EPB service function (specialty) to command the EPB out of service/maintenance mode.
• Verify the parking brake applies and releases normally.

---

✅ After Repair

• 🦶 Before driving, pump the brake pedal 10-15 times until it feels firm (this seats the pistons against the new pads).
• 🧴 Check the brake fluid level and top off with DOT 3 brake fluid if needed.
• 🔍 Check for leaks, and confirm both rear wheels spin freely with the parking brake released.
• 🛣️ Bed-in the brakes: make 6-10 moderate stops from ~40 to ~10 mph, allowing short cool-down between stops. Avoid hard stops until bedding is complete.
• 👂 Listen for scraping/grinding; mild smell is normal for the first drive.

---

💰 DIY vs Shop Cost

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

DIY Cost: $160-$420 (parts only)

You Save: $290-$430 by doing it yourself!

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

---

🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.