🔧 GLA - Front Brake Pads & Rotors Replacement

You’ll be removing the front wheels, swapping the brake pads and rotors, then reassembling everything with the correct torque. This restores braking performance and fixes common issues like pulsation (warped rotors) or squealing (worn pads).

Difficulty Level: Intermediate | Estimated Time: 2-4 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a level surface and support the A4—never rely on a jack alone.
• ⚠️ Brakes may be hot; let components cool before touching.
• ⚠️ Brake dust is harmful—use brake cleaner, not compressed air.
• ⚠️ Keep brake fluid off paint; it damages finishes quickly.
• ⚠️ Do not press the brake pedal with a caliper removed.
• ⚠️ No battery disconnect is required for front brakes on your GLA.

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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 wheel bolt socket
• 1/2" drive breaker bar
• 1/2" drive torque wrench (20-200 Nm range)
• 7mm hex bit socket
• E18 external Torx socket
• T30 Torx bit
• Flat trim/pry tool
• Large C-clamp or brake caliper piston compressor (specialty)
• Wire brush
• Small bungee cord
• Brake cleaner spray
• High-temp silicone brake grease
• Anti-seize compound
• Shop rags
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Front brake pad set - Qty: 1
• Front brake rotors - Replace in pairs - Qty: 2
• Front brake pad wear sensor - Qty: 1
• Front caliper bracket bolts - Replace in pairs per side - Qty: 4
• Front rotor retaining screw - Replace in pairs - Qty: 2
• Brake cleaner - Qty: 1
• Brake fluid DOT 4 - Top-off as needed - Qty: 1

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📋 Before You Begin

• 🧰 Park on level ground, set the parking brake, and chock the rear wheels.
• Open the hood and locate the brake fluid reservoir; make sure it’s not overfilled (fluid rises when you compress pistons).
• Loosen the front wheel bolts with a 17mm wheel bolt socket and breaker bar before lifting.
• Brake piston compressor = tool that pushes piston back.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Lift and secure the front end

• Place wheel chocks behind the rear tires.
• Use a floor jack at the correct front jack point and raise the vehicle.
• Set the vehicle onto jack stands and gently rock-check stability.

Step 2: Remove the front wheels

• Remove wheel bolts using a 17mm wheel bolt socket and breaker bar.
• Set wheels aside flat so they can’t roll.

Step 3: Remove the caliper (do not let it hang)

• Turn the steering to give yourself more room at the caliper.
• If equipped with an outer spring clip, pop it off carefully using a flat trim/pry tool.
• Remove the caliper guide/slider bolts using a 7mm hex bit socket.
• Lift the caliper off the rotor and support it with a small bungee cord (hook to the strut spring).
• Never hang the caliper by the hose.

Step 4: Remove the old pads and wear sensor

• Pull the pads out of the bracket by hand.
• Disconnect the wear sensor from the pad and unplug it from its connector (usually clipped to the strut area).
• Use shop rags to wipe dirt from the pad hardware area.

Step 5: Remove the caliper bracket (carrier)

• Remove the caliper bracket bolts using an E18 external Torx socket and breaker bar.
• Set the bracket aside.
• During reassembly: Torque caliper bracket bolts to 115 Nm (85 ft-lbs).

Step 6: Remove the rotor

• Remove the rotor retaining screw using a T30 Torx bit.
• Pull the rotor off the hub. If stuck, wiggle it and clean rust at the hub edge with a wire brush.
• During reassembly: Torque rotor retaining screw to 10 Nm (7 ft-lbs).

Step 7: Clean the hub and prep the new rotor

• Clean the hub face with a wire brush until it’s smooth and flat.
• Apply a very thin film of anti-seize compound to the hub center (avoid wheel studs/bolt seats and rotor friction surface).
• Spray the new rotor friction surfaces with brake cleaner spray and wipe with shop rags (removes shipping oil).

Step 8: Install the new rotor

• Place the new rotor onto the hub and align the retaining screw hole.
• Install the new retaining screw using a T30 Torx bit and snug it: Torque to 10 Nm (7 ft-lbs).

Step 9: Reinstall the caliper bracket and hardware

• Position the bracket over the rotor.
• Install new bracket bolts using an E18 external Torx socket.
• Tighten with a torque wrench: Torque to 115 Nm (85 ft-lbs).

Step 10: Compress the caliper piston

• Place an old pad against the piston face (protects the piston).
• Use a large C-clamp or brake caliper piston compressor (specialty) to slowly push the piston fully back.
• Watch the brake fluid reservoir level while compressing; remove fluid only if it’s close to overflowing.
• Go slow to avoid damaging seals.

Step 11: Install the new pads and wear sensor

• Apply a light coat of high-temp silicone brake grease to pad ears/slide points (not the pad friction material).
• Install the inner and outer pads into the bracket.
• Install the new wear sensor into the correct pad and route the wire exactly like the original, then connect it.

Step 12: Reinstall the caliper

• Slide the caliper over the new pads.
• Install the guide/slider bolts using a 7mm hex bit socket.
• Tighten with a torque wrench: Torque to 30 Nm (22 ft-lbs).
• Reinstall the outer spring clip (if equipped) using a flat trim/pry tool.

Step 13: Reinstall wheels

• Install the wheels and hand-start all wheel bolts.
• Lower the vehicle off the jack stands using the floor jack.
• Torque wheel bolts in a star pattern using a torque wrench: Torque to 130 Nm (96 ft-lbs).

Step 14: Repeat on the other front side

• Repeat Steps 2 through 13 for the other front wheel.
• Always replace pads/rotors in pairs.

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✅ After Repair

• Before starting the engine, pump the brake pedal 10-15 times until it feels firm.
• Check brake fluid level and top off with DOT 4 if needed.
• Start the engine and confirm the brake pedal stays firm and does not sink.
• Perform a cautious test drive: verify straight braking and no grinding noises.
• Pad bedding (recommended): make 6-10 medium stops from 35 mph to 5 mph, letting brakes cool 30-60 seconds between stops; then drive 5-10 minutes without hard braking to cool.
• If the brake warning/wear light stays on, recheck the wear sensor connection and routing.

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💰 DIY vs Shop Cost

Shop Cost: $550-$1,050 (parts + labor)

DIY Cost: $180-$450 (parts only)

You Save: $370-$600 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-3 hours.

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🎯 Ready to get started?

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