🔧 XT4 - Rear Brake Pad Replacement

This is an intermediate job because your XT4 uses an electronic parking brake, or EPB. Put the EPB into service mode with a compatible scan tool before compressing either rear caliper piston. Forcing a piston back without service mode can damage the actuator.

Difficulty Level: Intermediate | Estimated Time: 1.5-2.5 hours

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⚠️ Safety & Precautions

• ⚠️ Support your XT4 with jack stands. Never work underneath a vehicle supported only by a jack.
• ⚠️ Release the electronic parking brake before lifting the vehicle.
• ⚠️ Use a scan tool to enter EPB service mode before removing the calipers or compressing the pistons.
• ⚠️ Stop if a piston won’t compress with moderate pressure. Don’t force or rotate it.
• ⚠️ Never press the brake pedal while a caliper is removed.
• ⚠️ Don’t let a caliper hang from its rubber brake hose.
• ⚠️ Keep brake cleaner and grease away from pad friction surfaces and rotors.
• ⚠️ Battery disconnection isn’t normally required when using the proper EPB service procedure.

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🔧 Required Tools

You'll need the following tools for this repair:

• 19mm deep socket
• Metric socket set (10-19mm)
• 3/8-inch drive ratchet
• 1/2-inch drive breaker bar
• 1/2-inch drive torque wrench (30-150 ft-lbs)
• 3/8-inch drive torque wrench (10-50 ft-lbs)
• EPB-capable diagnostic scan tool (specialty)
• Disc brake piston compression tool (specialty)
• Flat-blade screwdriver (6-inch)
• Brake caliper hanger hook (specialty)
• Small brass wire brush
• Floor jack (rated 2-ton minimum)
• Jack stands (rated 2-ton minimum)
• Wheel chocks (pair)
• Safety glasses
• Nitrile gloves

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Rear ceramic brake pad set - Qty: 1
• Rear brake pad hardware kit - Qty: 1, unless included with pads
• Silicone-based brake lubricant - Qty: 1
• Brake parts cleaner - Qty: 1 can
• Rear brake rotors - Qty: 2, only if worn, scored, cracked, or below specification

Replace the pads on both rear wheels together. The rear-brake aisle is open beside this guide.

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📋 Before You Begin

• Park on firm, level ground. Shift into Park and switch the ignition off.
• Release the electronic parking brake, then place wheel chocks firmly against both sides of a front tire.
• Open the hood and check the brake-fluid reservoir. Remove excess fluid first if it’s already at the maximum line.
• Connect the EPB-capable scan tool to the diagnostic connector below the driver-side dashboard.
• Turn the ignition on without starting the engine.
• Select the scan-tool path matching Chassis/Brake > Electronic Parking Brake > Service Mode. Menu wording varies by scan-tool brand.
• Wait for confirmation that the parking-brake actuators have retracted. Cadillac confirms the XT4 uses an electric parking brake, and rear service requires managing that system correctly. cadillaccanada.ca)

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Loosen the rear wheel nuts

• Use the 19mm deep socket and 1/2-inch drive breaker bar to loosen each rear wheel nut approximately one-half turn.
• Keep the wheels on the ground during this step so they can’t rotate.

Step 2: Lift and support the rear

• Use the floor jack at the approved rear lifting point.
• Place the jack stands beneath the approved rear support points, then lower the vehicle securely onto them.
• Give your XT4 a careful stability check before removing either wheel.
• A solid stand beats a brave mechanic.

Step 3: Remove both rear wheels

• Use the 19mm deep socket and 3/8-inch drive ratchet to remove the loosened wheel nuts.
• Remove both rear wheels and slide them away from your work area.

Step 4: Confirm EPB service mode

• Use the EPB-capable diagnostic scan tool to verify that service mode remains active.
• Do not continue if the scan tool reports an actuator fault or service mode failed.

Step 5: Remove the first rear caliper

• Use the correctly fitting socket from the metric socket set and the 3/8-inch drive ratchet to remove both caliper guide-pin bolts.
• Hold the guide pin with an appropriate wrench from the set if it turns with the bolt.
• Lift the caliper straight off the pads. Use the flat-blade screwdriver only for gentle assistance if it’s tight.
• Support the caliper with the brake caliper hanger hook. Don’t twist or stretch the hose.

Step 6: Remove the old pads and hardware

• Pull the inner and outer pads from the caliper bracket by hand.
• Use the flat-blade screwdriver to remove the stainless abutment clips. These clips are the small tracks on which the pad ears slide.
• Compare the inner and outer pad wear. A major difference can indicate a seized guide pin or sticking pad hardware.

Step 7: Inspect the rotor and caliper

• Inspect the rotor for deep grooves, cracks, heavy rust scaling, blue heat spots, or a pronounced outer lip.
• Check the caliper dust boot for tears or brake-fluid leakage.
• Move both guide pins by hand. They should slide smoothly without binding.
• Replace both rear rotors if either rotor is damaged or below its minimum-thickness marking.

Step 8: Clean the pad contact points

• Use the brass wire brush and brake parts cleaner to clean the bracket surfaces beneath the abutment clips.
• Install the new clips by hand, confirming each clip sits completely flat.
• Apply a very thin coat of silicone brake lubricant beneath the clips and at the guide-pin contact surfaces.
• Don’t put lubricant on the rotor, pad friction material, or rubber components unless the lubricant specifically states it’s rubber-safe.

Step 9: Compress the caliper piston

• Place an old pad against the piston face.
• Use the disc brake piston compression tool to push the piston slowly and evenly into the caliper.
• Watch the brake-fluid reservoir while compressing the piston because the fluid level will rise.
• Stop immediately if the piston resists strongly. Recheck EPB service mode rather than applying more force.

Step 10: Install the new rear pads

• Apply a paper-thin coating of silicone brake lubricant to the pad ears where they contact the new clips.
• Fit the inner and outer pads into the bracket by hand.
• Confirm the pads slide without binding and that any wear indicator matches the position of the removed pad.

Step 11: Reinstall the caliper

• Lower the caliper over the new pads without twisting the brake hose.
• Use the correctly fitting socket from the metric socket set and the 3/8-inch drive ratchet to start both guide-pin bolts by hand.
• Use the 3/8-inch drive torque wrench to tighten the guide-pin bolts to 31 Nm (23 ft-lbs). howtoo.com

Step 12: Repeat on the opposite side

• Repeat Steps 5 through 11 on the other rear wheel.
• Confirm both calipers are secure and both brake hoses follow their original routing.

Step 13: Reinstall the wheels

• Clean obvious dirt from the wheel-mounting faces with the brass wire brush.
• Install both wheels and start every wheel nut by hand.
• Snug the wheel nuts evenly with the 19mm deep socket and 3/8-inch drive ratchet.
• Use the floor jack to raise your XT4, remove the jack stands, and lower it to the ground.
• Use the 1/2-inch drive torque wrench and 19mm deep socket to tighten the wheel nuts in a star pattern to 140 Nm (103 ft-lbs). howtoo.com

Step 14: Exit EPB service mode

• Keep the transmission in Park and use the EPB-capable diagnostic scan tool.
• Select Chassis/Brake > Electronic Parking Brake > Exit Service Mode, or the equivalent menu on your tool.
• Wait until the scan tool confirms that service mode has ended.
• Apply and release the electronic parking brake once. Confirm there’s no warning light or service message.

Step 15: Seat the brake pads

• With the engine off, press the brake pedal slowly several times until it becomes firm.
• Check the brake-fluid reservoir and adjust the level only with the correct fresh brake fluid.
• Don’t move your XT4 until the pedal is firm and the electronic parking brake operates normally.

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✅ After Repair

• Start the engine while holding the brake pedal. The pedal should remain firm and shouldn’t sink steadily.
• Check around both rear calipers for fluid leaks, loose bolts, trapped hoses, or misplaced hardware.
• Test the electronic parking brake before driving.
• Make several gentle stops at low speed in a safe area before entering traffic.
• Follow the pad manufacturer’s bedding procedure. Avoid panic stops and holding the pedal down after a hard stop during initial break-in.
• Stop driving if you hear metal grinding, the vehicle pulls sharply, the pedal feels soft, or a brake warning appears.

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💰 DIY vs Shop Cost

Shop Cost: $300-$550 (parts + labor)

DIY Cost: $45-$180 (pads and consumables, excluding tools)

You Save: $120-$400 by doing it yourself!

Local labor rates vary considerably. This repair typically occupies a shop for approximately 1-2 hours.

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🎯 Ready to get started?

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