🔧 Q50 - Rear Brake Pad Replacement

You’ll remove the rear wheels, swing the rear brake calipers out of the way, swap the pads and hardware, then compress the caliper pistons so everything fits back together. Rear pads wear from normal braking and can cause squealing, grinding, or longer stopping distances when they’re thin.

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

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⚠️ Safety & Precautions

• ⚠️ Work on level ground and chock the front wheels before lifting the rear.
• ⚠️ Support the car with jack stands; never rely on a floor jack alone.
• ⚠️ Do not press the brake pedal while a caliper is off the rotor.
• ⚠️ Brake dust is harmful; use brake cleaner, not compressed air.
• ⚠️ If your Q50 has a mechanical parking brake, make sure it is fully released before starting.

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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 socket
• 1/2" drive breaker bar
• 1/2" drive torque wrench (20-150 ft-lbs)
• 14mm socket
• 3/8" drive ratchet
• 3/8" drive torque wrench (10-80 ft-lbs)
• 19mm socket
• Large C-clamp
• Flat-blade screwdriver
• Needle-nose pliers
• Wire hook or bungee cord
• Brake parts cleaner
• High-temp silicone brake grease
• Shop rags
• Nitrile gloves
• Safety glasses

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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 (clips/shims) - Qty: 1
• Brake anti-squeal compound - Qty: 1
• Brake cleaner - Qty: 1

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📋 Before You Begin

• Park your Q50 on a flat surface, shift to Park, and fully release the parking brake.
• Place wheel chocks at the front tires so the car can’t roll.
• Loosen (crack loose) the rear wheel lug nuts about 1/2 turn using a 21mm socket and breaker bar before lifting.
• Open the hood and locate the brake fluid reservoir; this helps you watch for overflow when you compress the pistons.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Lift and support the rear

• Use a floor jack to lift the rear of the car at the proper lift point.
• Place jack stands under solid rear support points and lower the car onto them.
• Remove the rear wheels using a 21mm socket.

Step 2: Find the caliper bolts and inspect everything

• Look at the rear brake assembly: the caliper is the clamp that squeezes the pads, and the caliper bracket is the fixed mount the pads slide in.
• Check the rotor for deep grooves or heavy rust lips. If rotors are badly worn, replace them.

Step 3: Remove the caliper (keep it supported)

• Remove the lower and upper caliper slide bolts using a 14mm socket and 3/8" drive ratchet.
• Carefully lift the caliper off the bracket.
• Hang the caliper from the suspension using a wire hook or bungee cord.
• Do not let the caliper hang by the brake hose.

Step 4: Remove old pads and hardware

• Slide the old inner and outer pads out by hand (use a flat-blade screwdriver gently if stuck).
• Remove the stainless pad clips from the bracket using a flat-blade screwdriver.
• Spray the bracket pad ledges with brake parts cleaner and wipe with shop rags.

Step 5: Service the slide pins (important for even braking)

• Pull the slide pins out of the bracket by hand.
• Wipe them clean with shop rags, then apply a thin coat of high-temp silicone brake grease.
• Reinsert the slide pins and make sure they move smoothly.

Step 6: Compress the caliper piston

• The caliper piston is the round plunger that pushes the inner pad. You must push it back in to fit the thicker new pads.
• Place an old pad against the piston face, then use a large C-clamp to slowly compress the piston fully.
• Watch the brake fluid reservoir while you compress; stop if it looks like it may overflow.

Step 7: Install new hardware and pads

• Install the new pad clips into the bracket by hand.
• Apply a very thin layer of high-temp silicone brake grease where the pad “ears” touch the clips (metal-to-metal contact points only).
• Install the new inner and outer pads into the bracket.
• If your new pads include shims, install them exactly as provided.
• Apply a thin layer of brake anti-squeal compound to the back of the pads (not on the friction material).

Step 8: Reinstall the caliper and torque bolts

• Lower the caliper over the new pads.
• Install the slide bolts by hand first to avoid cross-threading, then tighten using a 14mm socket and 3/8" drive torque wrench.
• Torque to 25 Nm (18 ft-lbs) for the rear caliper slide bolts.

Step 9: Reinstall wheels and torque lug nuts

• Reinstall the wheels and snug the lug nuts using a 21mm socket.
• Lower the car off the jack stands using the floor jack.
• Tighten lug nuts in a star pattern using a 1/2" drive torque wrench.
• Torque to 108 Nm (80 ft-lbs) for the wheel lug nuts.

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✅ After Repair

• With the engine off, press the brake pedal slowly 10-15 times until it feels firm (this seats the pistons against the pads).
• Check the brake fluid level and top off only if needed.
• Do a slow test drive in a safe area and confirm no pulling, grinding, or warning lights.
• Bed-in (break-in) the pads: make 6-10 medium stops from 35 mph to 5 mph, with 30-60 seconds between stops. Avoid hard stops for the first 150-200 miles.

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💰 DIY vs Shop Cost

Shop Cost: $250-$450 (parts + labor)

DIY Cost: $60-$160 (parts only)

You Save: $190-$290 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-1.5 hours.

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🎯 Ready to get started?

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