🔧 A3 - Rear Brake Pads & Rotors Replacement

You’ll replace the rear brake pads and rotors, then put the electronic parking brake (EPB) into service mode so the rear caliper pistons can retract safely. This keeps the EPB motor from being damaged and makes the job much easier.

Difficulty Level: Intermediate | Estimated Time: 2.0-3.5 hours

Assumption: your A3 has rear electronic parking brake calipers (common).

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⚠️ Safety & Precautions

• ⚠️ Support the car with jack stands before working under/near wheels.
• ⚠️ Do not press the brake pedal while a caliper is off the rotor.
• ⚠️ Use EPB service mode before compressing rear pistons (this retracts the parking-brake motor).
• ⚠️ Brake dust is harmful—wear a dust mask and avoid blowing dust with compressed air.
• ⚠️ Brake fluid can damage paint—wipe spills immediately.

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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
• Safety glasses
• Nitrile gloves
• Dust mask
• Breaker bar (1/2" drive)
• Torque wrench (20-200 Nm range)
• 17mm socket
• 13mm socket
• 15mm wrench
• 21mm socket
• Torx T30 bit
• Flat trim tool
• Brake caliper piston rewind tool (specialty)
• OBDeleven or VCDS scan tool (specialty)
• Bungee cord
• Wire brush
• Brake cleaner spray
• Shop rags
• Small drain pan

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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 - Qty: 2
• Rear pad wear sensor (if equipped) - Qty: 1
• Rear caliper carrier bolts (single-use) - Qty: 4
• Rear caliper guide pin bolts - Qty: 2
• Brake rotor set screws - Qty: 2
• Brake lubricant (silicone/PTFE) - Qty: 1
• Anti-seize compound - Qty: 1
• Brake fluid (DOT 4) - Qty: 1 liter

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📋 Before You Begin

• Park on level ground, steering straight, and place wheel chocks at the front wheels.
• Release the parking brake and keep the ignition on (engine off) for EPB service mode.
• Set up your OBDeleven or VCDS scan tool (a scan tool is a plug-in device that can command modules like the parking brake).
• Open the hood and check the brake fluid level; if it’s near MAX, be ready to remove a little fluid (use shop rags and a small drain pan).

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Put the EPB into service mode

• Plug in your OBDeleven or VCDS scan tool (specialty) to the OBD port (under the dash).
• Command the parking brake into “service mode/open/retract” (wording varies by tool).
• You should hear the rear motors run.

Step 2: Loosen rear wheel bolts and raise the rear

• Use a 17mm socket and breaker bar (1/2" drive) to crack loose the rear wheel bolts about 1/4 turn.
• Lift the rear with a floor jack (rated 3-ton minimum) and set the car onto jack stands (rated 3-ton minimum).
• Remove the wheel bolts using the 17mm socket and remove both rear wheels.

Step 3: Remove the rear caliper

• Use a 13mm socket to remove the two caliper guide bolts while holding the slide pin flats with a 15mm wrench.
• Lift the caliper off the rotor and hang it using a bungee cord (do not let it hang by the brake hose).

Step 4: Remove old pads and inspect hardware

• Pull the inner/outer pads out by hand (use a flat trim tool gently if stuck).
• Spray dust and grime with brake cleaner spray and wipe with shop rags.
• Inspect the caliper slide pins for smooth movement (they should glide in and out).

Step 5: Remove the caliper carrier and rotor

• Use a 21mm socket and breaker bar (1/2" drive) to remove the 2 caliper carrier bolts.
• Remove the rotor retaining screw using a Torx T30 bit.
• Pull the rotor off. If it’s stuck, tap the rotor hat lightly (keep fingers clear).

Step 6: Clean the hub and install the new rotor

• Use a wire brush to clean rust off the hub face (this helps prevent rotor wobble).
• Apply a very thin layer of anti-seize compound to the hub face (avoid the wheel studs/bolt seats and rotor friction surface).
• Install the new rotor and install the new set screw using a Torx T30 bit.
• Torque to 4 Nm (35 in-lbs)

Step 7: Reinstall the caliper carrier

• Reinstall the carrier using a 21mm socket.
• Torque to 90 Nm (66 ft-lbs) + 90° turn
• If bolts are “single-use,” always replace them.

Step 8: Retract the rear caliper piston

• Use a brake caliper piston rewind tool (specialty) (this tool presses and turns the piston at the same time) to wind the piston back slowly until it seats.
• Watch the brake fluid reservoir while compressing; remove a little fluid if it’s getting too high.

Step 9: Install new pads

• Apply a thin film of brake lubricant (silicone/PTFE) to pad backing plates and contact points (do not get any on pad/rotor friction surfaces).
• Install the new pads into the carrier in the same orientation as removed.
• If equipped, reconnect the wear sensor (route it like the original so it won’t rub the wheel).

Step 10: Reinstall the caliper

• Lower the caliper over the new pads and align the slide pins.
• Install guide bolts using a 13mm socket while holding pin flats with a 15mm wrench.
• Torque to 35 Nm (26 ft-lbs)

Step 11: Repeat on the other rear side

• Perform Steps 3 through 10 on the other rear wheel.

Step 12: Exit EPB service mode

• Use your OBDeleven or VCDS scan tool (specialty) to command the EPB to “close/basic setting/normal mode.”
• Listen for the motors to finish cycling.

Step 13: Reinstall wheels and torque

• Install the wheels and hand-thread all bolts.
• Lower the car and torque wheel bolts using a torque wrench (20-200 Nm range).
• Torque to 120 Nm (89 ft-lbs)

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✅ After Repair

• Pump the brake pedal 10-15 times until it feels firm (this seats the pads).
• Check brake fluid level and top off with DOT 4 only if needed.
• Test the parking brake function (apply/release) before driving.
• Perform a gentle pad/rotor break-in: 6-10 moderate stops from 60→20 km/h, with cooling time between stops.
• If you see an EPB or brake warning light, rescan with the scan tool and clear any stored faults after confirming operation.

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💰 DIY vs Shop Cost

Shop Cost: ₹18,000-₹35,000 (parts + labor)

DIY Cost: ₹8,000-₹20,000 (parts only)

You Save: ₹10,000-₹15,000 by doing it yourself!

Shop labor rates vary but typically run ₹1,000-₹2,500/hour. This repair takes a shop approximately 2.0-3.0 hours.

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