🔧 K900 - Rear Brake Pad Replacement

You’ll be removing the rear wheels, retracting the electronic parking brake (EPB) so the rear calipers can compress safely, then swapping the pads and reassembling with proper lubrication and torque. This restores braking performance and prevents rotor damage from worn pads.

Difficulty Level: Intermediate | Estimated Time: 1.5-3.0 hours

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⚠️ Safety & Precautions

• ⚠️ Support the car with jack stands; never rely on a jack alone.
• ⚠️ Do not press the brake pedal with a caliper removed (the piston can pop out and leak).
• ⚠️ The rear calipers use an electronic parking brake (EPB); retract it into service mode before pushing the piston in.
• ⚠️ Keep grease off pad/rotor friction surfaces; use brake cleaner if contaminated.
• ⚠️ Battery disconnect is not required, but keep ignition OFF unless entering EPB service mode.

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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
• 21mm lug socket
• Breaker bar (1/2" drive)
• Torque wrench (10-200 ft-lbs range)
• 14mm socket
• 17mm socket
• Ratchet (3/8" drive)
• Flat-head screwdriver
• C-clamp brake piston compressor
• Brake caliper hanger hook
• Wire brush
• Brake parts cleaner
• Nitrile gloves
• Safety glasses
• Scan tool with EPB service function (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 hardware kit (abutment clips) - Qty: 1
• Silicone brake lubricant - Qty: 1
• Brake cleaner spray - Qty: 1

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📋 Before You Begin

• 🧰 Park on level ground, put the transmission in P, and chock the front wheels.
• 🧰 Make sure the parking brake is released before lifting the rear.
• 🧰 Loosen rear lug nuts 1/4 turn using a 21mm lug socket and breaker bar before the tires leave the ground.
• 🧰 Have your brake caliper hanger hook ready (this is a metal hook that supports the caliper so it doesn’t hang by the brake hose).
• 🧰 Assumption: torque specs can vary by production; use the values below unless your service information specifies different.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Lift and secure the rear

• Place wheel chocks at the front tires.
• Lift the rear using a floor jack (rated 3-ton minimum) at the proper rear jacking point.
• Set the car onto jack stands (rated 3-ton minimum) under solid rear support points.
• Remove the rear wheels using a 21mm lug socket and ratchet.

Step 2: Put the EPB into service mode (required)

• Method A (preferred): Use a scan tool with EPB service function (specialty) and run EPB > Maintenance/Pad Replacement Mode to retract the actuators.
• Method B (if supported on your K900): Turn ignition ON (engine OFF). Use the EPB switch to command release and follow the on-screen cluster prompts if a maintenance mode appears. If no clear maintenance mode is shown, do not force the pistons—use Method A.
• Don’t skip this—EPB damage is expensive.

Step 3: Remove the caliper from the bracket

• Turn the steering wheel is not needed for the rear; position yourself for clear access.
• Locate the two caliper slide pin bolts on the back of the caliper.
• Use a 14mm socket and ratchet to remove the slide pin bolts.
• Lift the caliper off the bracket and support it with a brake caliper hanger hook (do not let it hang by the hose).

Step 4: Remove old pads and hardware

• Pull the old pads out of the bracket by hand. If stuck, gently pry with a flat-head screwdriver.
• Remove the old abutment clips (hardware) from the bracket.
• Clean pad contact points on the bracket using a wire brush, then spray with brake parts cleaner.

Step 5: Compress the caliper piston

• Confirm the EPB is fully retracted (service mode completed) before pushing the piston in.
• Use a C-clamp brake piston compressor to slowly push the piston straight back into the caliper.
• If you feel hard resistance, stop—re-check EPB service mode.

Step 6: Install new hardware and pads

• Install new abutment clips from the rear brake pad hardware kit into the bracket.
• Apply a thin film of silicone brake lubricant where the pad “ears” slide on the clips (not on the pad friction material).
• Install the new pads into the bracket in the same orientation as the originals.

Step 7: Reinstall the caliper and torque bolts

• Place the caliper over the new pads.
• Reinstall the slide pin bolts using a 14mm socket and ratchet.
• Tighten slide pin bolts using a torque wrench: Torque to 34 Nm (25 ft-lbs).
• If you removed the caliper bracket (only if necessary), reinstall bracket bolts using a 17mm socket and torque wrench: Torque to 78 Nm (58 ft-lbs).

Step 8: Reinstall wheels

• Reinstall wheels and hand-thread 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 118 Nm (87 ft-lbs).

Step 9: Exit EPB service mode

• If you used a scan tool, use the scan tool with EPB service function (specialty) to command EPB > Close/Apply/Exit Maintenance Mode.
• Verify the EPB applies and releases normally using the EPB switch.

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✅ After Repair

• 🧪 Before moving the car, press the brake pedal 10-15 times until it feels firm.
• 🧪 Check brake fluid level visually; top up only if needed (do not overfill).
• 🧪 Do a cautious test drive: confirm normal braking and that the EPB works correctly.
• 🧪 Pad bed-in (break-in): make 6-10 moderate stops from 30-40 mph, letting brakes cool a bit between stops.
• 🧪 Re-check for unusual noises and verify lug nut torque after a short drive.

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💰 DIY vs Shop Cost

Shop Cost: $350-$650 (parts + labor)

DIY Cost: $80-$220 (parts only)

You Save: $270-$430 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-2.5 hours.

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🎯 Ready to get started?

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