🔧 340i - Rear Brake Pad Replacement

You’ll remove the rear wheels, swing the rear calipers out of the way, retract the caliper pistons, and install new pads (and the wear sensor). On your 340i, the rear parking brake is electronic, so you must put the parking brake system into “service mode” before pushing the pistons back.

Difficulty Level: Intermediate | Estimated Time: 1.5-3 hours

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⚠️ Safety & Precautions

• ⚠️ Work on level ground and use jack stands—never rely on a jack alone.
• ⚠️ Do not press the brake pedal with a caliper removed; the piston can pop out.
• ⚠️ Electronic parking brake: retract/enter service mode first, or you can damage the actuator.
• ⚠️ Brake dust is harmful—use brake cleaner, not compressed air.
• ⚠️ Keep grease off pad friction material and rotor faces.

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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
• 17mm socket
• 3/8" drive ratchet
• 6" extension (3/8" drive)
• 7mm hex bit socket
• Torque wrench (10–200 Nm range)
• Flat trim tool
• Small flathead screwdriver
• Brake caliper piston compression tool (specialty)
• Mechanic’s wire or bungee cord
• Brake cleaner spray
• Nitrile gloves
• Safety glasses
• BMW-capable scan tool with EPB service mode (specialty)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Rear brake pad set - Qty: 1
• Rear brake pad wear sensor - Qty: 1
• Brake anti-squeal paste - Qty: 1
• Brake hardware kit - Qty: 1

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📋 Before You Begin

• Park on a flat surface, transmission in Park, and chock the front wheels.
• Turn the electronic parking brake OFF before lifting the car.
• Use your scan tool to retract the electronic parking brake (also called “service mode,” meaning the parking brake motor backs off so the piston can be pushed in safely).
• Tip: Read scan tool prompts carefully.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Retract the electronic parking brake (service mode)

• Connect your BMW-capable scan tool with EPB service mode (specialty).
• Run the parking brake service function to retract the rear calipers (wording varies by tool, commonly “Parking brake > Service/Workshop mode” or “Mounting position”).

Step 2: Loosen rear wheel bolts

• Use a 17mm socket and 3/8" drive ratchet to loosen the rear wheel bolts about 1 turn while the car is on the ground.

Step 3: Lift and support the rear

• Lift the rear using a floor jack (rated 3-ton minimum) and support with jack stands (rated 3-ton minimum).
• Keep wheel chocks at the front wheels.

Step 4: Remove the rear wheels

• Remove the wheel bolts using the 17mm socket and 3/8" drive ratchet, then remove the wheels.

Step 5: Unplug and remove the rear brake pad wear sensor

• Locate the wear sensor wire at the rear brake (typically one rear wheel has it).
• Use a flat trim tool to open the connector box and release the connector.
• Use a small flathead screwdriver to gently pry the sensor out of the pad.
• Tip: Don’t pull on the wire.

Step 6: Remove the caliper spring clip

• Use a small flathead screwdriver to carefully pry off the outer spring clip from the caliper.

Step 7: Remove rear caliper guide pins

• Pop off the rubber caps over the guide pins using a flat trim tool.
• Use a 7mm hex bit socket, 3/8" drive ratchet, and 6" extension (3/8" drive) to remove the two guide pins.

Step 8: Swing the caliper up and support it

• Lift the caliper off the bracket and support it using mechanic’s wire or bungee cord.
• Do not let the caliper hang by the brake hose.

Step 9: Remove the old pads and hardware

• Pull the inner and outer pads out by hand.
• If your new pads come with new clips, remove the old clips from the bracket.
• Spray the bracket/pad contact areas with brake cleaner spray and wipe clean.

Step 10: Retract the rear caliper piston

• Place the old inner pad against the piston face.
• Use a brake caliper piston compression tool (specialty) to slowly push the piston fully back into the caliper.
• If the piston will not push back smoothly, stop and re-check that EPB service mode is active with the BMW-capable scan tool with EPB service mode (specialty).
• Tip: Go slow to avoid seal damage.

Step 11: Install new hardware and pads

• Install any new pad clips from the brake hardware kit.
• Apply a thin layer of brake anti-squeal paste to the pad backing plates where they contact the caliper/bracket (not on the pad friction surface).
• Install the new pads into the bracket in the same positions as removed.

Step 12: Reinstall caliper and guide pins

• Lower the caliper over the new pads.
• Install the guide pins using the 7mm hex bit socket, 3/8" drive ratchet, and 6" extension (3/8" drive).
• Tighten with a torque wrench: Torque to 30 Nm (22 ft-lbs).
• Reinstall the rubber guide pin caps by hand.

Step 13: Reinstall the caliper spring clip

• Reinstall the clip by hand and seat it using a small flathead screwdriver carefully.

Step 14: Install the new wear sensor

• Press the new sensor into the pad until fully seated.
• Route the wire exactly like the original and reconnect it in the connector box using a flat trim tool as needed.

Step 15: Reinstall wheels and torque the wheel bolts

• Install wheels and hand-thread bolts.
• Lower the car.
• Use a torque wrench and 17mm socket: Torque to 140 Nm (103 ft-lbs).

Step 16: Exit EPB service mode and reset the brake service reminder

• Use the BMW-capable scan tool with EPB service mode (specialty) to exit service mode (the tool may call it “End mounting position”).
• Reset the rear brake pad service reminder in iDrive: Vehicle Info > Vehicle Status > Service Required > Rear brake pads > Reset.

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✅ After Repair

• With the car on the ground, pump the brake pedal 10–15 times until it feels firm.
• Start the engine and confirm the brake pedal remains firm.
• Apply and release the electronic parking brake to confirm normal operation.
• Do a slow test drive and make a few gentle stops to confirm no pulling or noises.
• Pad bedding (break-in): do 8–10 moderate stops from 40–10 mph, with cool-down time between stops.

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💰 DIY vs Shop Cost

Shop Cost: ₹12,000-₹25,000 (parts + labor)

DIY Cost: ₹5,000-₹14,000 (parts only)

You Save: ₹7,000-₹11,000 by doing it yourself!

Shop labor rates vary but typically run ₹2,000-₹4,000/hour. This repair takes a shop approximately 1.5-2.5 hours.

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🎯 Ready to get started?

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