🔧 A4 - Rear Brake Pads & Rotor Replacement

You’ll remove the rear wheels, take off the rear calipers and caliper brackets, replace the rotors, then install new pads. Because your A4 uses an electronic parking brake (EPB), you must retract the parking brake motors into “service mode” before compressing the caliper pistons.

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

---

⚠️ Safety & Precautions

• 🛑 Support the car on jack stands; never rely on a floor jack alone.
• 🔥 Brakes get extremely hot—work only when fully cool.
• ⚡ Use EPB service mode before pushing pistons in, or you can damage the parking brake motors.
• 🧴 Avoid inhaling brake dust; use brake cleaner and wear a mask.
• 🔌 Battery disconnect is typically not required, but keep the ignition OFF while working.

---

🔧 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
• 17mm socket
• 1/2" drive breaker bar
• 1/2" drive torque wrench (20-200 Nm range)
• 3/8" drive ratchet
• 3/8" drive torque wrench (5-60 Nm range)
• 13mm socket
• 15mm open-end wrench
• M12 triple-square bit socket
• M14 triple-square bit socket
• Torx T30 bit
• Flat trim tool
• Brake caliper piston compression tool (specialty)
• OBD scan tool with Audi EPB service function (specialty)
• Wire brush
• Bungee cord
• Rubber mallet
• Safety glasses
• Nitrile gloves
• Dust mask

---

🔩 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 caliper carrier bolts - Replace in pairs per side - Qty: 4
• Brake pad hardware kit - Qty: 1
• Brake lubricant (silicone or ceramic) - Qty: 1
• Brake cleaner - Qty: 1
• DOT 4 brake fluid - Qty: 1 bottle

---

📋 Before You Begin

• 🅿️ Park on level ground, wheels straight, and place wheel chocks at the front wheels.
• 🔑 Turn ignition ON (engine OFF) only when putting the EPB into service mode; otherwise keep ignition OFF.
• 🧠 Assumption: Your A4 has EPB rear calipers; steps below follow the Audi EPB “lining change/service mode” process.
• 🧴 Open the hood and check brake fluid level; if it’s near MAX, be ready to siphon a little (fluid rises when pistons retract).

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Put the electronic parking brake (EPB) into service mode

• Plug in your OBD scan tool with Audi EPB service function (specialty).
• On the scan tool, go to the EPB function and run the lining change mode. Common names include Parking Brake > Basic Settings > Open Rear Parking Brake or Start lining change mode.
• Wait until the scan tool confirms the motors are fully retracted.
• EPB service mode retracts the caliper motors.

Step 2: Loosen rear wheel bolts and lift the rear

• Use a 17mm socket and breaker bar to loosen the rear wheel bolts 1/2 turn (do not remove yet).
• Use a floor jack (rated 3-ton minimum) to lift the rear at the correct jacking point, then set the car on jack stands (rated 3-ton minimum).
• Remove the wheel bolts with the 17mm socket and remove both rear wheels.

Step 3: Remove the rear caliper (do not hang it by the hose)

• Use a flat trim tool to pop off the caliper guide pin caps (if equipped).
• Use a 13mm socket on the guide bolts while holding the slide pin flats with a 15mm open-end wrench.
• Lift the caliper off the bracket and hang it from the suspension using a bungee cord.

Step 4: Remove old pads and the caliper carrier (bracket)

• Pull the inner and outer pads out by hand.
• Remove the caliper carrier bolts using an M12 triple-square bit socket (some cars use M14 triple-square bit socket).
• Set the carrier aside.
• Torque reference (install later): Torque to 90 Nm (66 ft-lbs)

Step 5: Remove the rotor

• Remove the rotor retaining screw using a Torx T30 bit.
• If the rotor is stuck, tap the rotor “hat” area with a rubber mallet until it breaks free.
• Clean the hub face with a wire brush so the new rotor sits flat.
• Torque reference (install later): Torque rotor screw to 4 Nm (35 in-lbs)

Step 6: Install the new rotor

• Spray the new rotor with brake cleaner to remove protective oil.
• Place the rotor onto the hub and install the retaining screw with a Torx T30 bit.
• Torque to 4 Nm (35 in-lbs)

Step 7: Reinstall the caliper carrier (bracket)

• Position the carrier over the new rotor and start the bolts by hand.
• Tighten using the M12 triple-square bit socket (or M14 triple-square bit socket as applicable) and a torque wrench.
• Torque to 90 Nm (66 ft-lbs)

Step 8: Compress the caliper piston

• Position the old inner pad against the piston (as a buffer).
• Use the brake caliper piston compression tool (specialty) to slowly push the piston straight back into the caliper.
• Go slowly and watch the brake fluid reservoir so it doesn’t overflow.
• Compression tool pushes piston in evenly.

Step 9: Install new pads and hardware

• Install any new abutment clips from the brake pad hardware kit onto the carrier (if included).
• Apply a thin layer of brake lubricant to pad ears/contact points (not on friction surfaces).
• Install the new inner and outer pads into the carrier.

Step 10: Reinstall the caliper

• Lower the caliper over the new pads.
• Install the guide bolts using a 13mm socket while holding the pin with a 15mm open-end wrench.
• Torque to 35 Nm (26 ft-lbs)
• Reinstall guide pin caps using a flat trim tool (press in by hand).

Step 11: Repeat on the other rear side

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

Step 12: Exit EPB service mode

• Use the OBD scan tool with Audi EPB service function (specialty) to close the parking brake / end lining change mode.
• Confirm the scan tool reports the EPB is back to normal operation.

Step 13: Reinstall wheels and lower the car

• Install wheel bolts hand-tight with a 17mm socket.
• Lower the car off the stands using the floor jack (rated 3-ton minimum).
• Torque wheel bolts in a star pattern using a torque wrench.
• Torque to 120 Nm (89 ft-lbs)

---

✅ After Repair

• 🦶 With engine OFF, press the brake pedal 10-15 times until it feels firm (this seats the pads).
• 🧴 Check brake fluid level and top off with DOT 4 brake fluid if needed.
• 🅿️ Test the parking brake function (apply/release) while stationary.
• 🚗 Do a careful test drive: start with gentle stops, then gradually increase braking.
• 🛞 Pad bedding (break-in): make 8-10 moderate stops from ~40 to 10 mph, letting brakes cool between stops.

---

💰 DIY vs Shop Cost

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

DIY Cost: ₹9,000-₹22,000 (parts only)

You Save: ₹9,000-₹13,000 by doing it yourself!

Shop labor rates vary but typically run ₹1,500-₹3,000/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.