🔧 Ascent - Rear Brake Pads & Rotor Replacement

This is an intermediate job, mainly because your Ascent has an electronic parking brake. You’ll place that system in maintenance mode, replace both rear rotors and the complete rear pad set, then reactivate and test the parking brake. The rear rotors are approximately 331 mm ventilated discs. s3.amazonaws.com

Difficulty Level: Intermediate | Estimated Time: 2.5-4 hours

Important assumption: The torque values below apply to the original rear brake hardware. Stop if your fasteners or calipers differ.

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⚠️ Safety & Precautions

• ⚠️ Put the electronic parking brake into maintenance mode before pushing the caliper pistons inward.
• ⚠️ Do not force or rotate the piston if it won’t retract. This can damage the parking-brake actuator.
• ⚠️ Support your Ascent with jack stands. Never work under a vehicle supported only by a jack.
• ⚠️ Keep grease, brake cleaner and dirty hands away from pad and rotor friction surfaces.
• ⚠️ Never press the brake pedal while a caliper is removed.
• ⚠️ Do not let a caliper hang from its rubber brake hose.
• ⚠️ Brake dust can irritate your lungs. Don’t use compressed air to clean it.
• ⚠️ Battery disconnection is not required for this procedure.

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🔧 Required Tools

You'll need the following tools for this repair:

• 19mm impact-rated socket
• 14mm socket
• 17mm socket
• 3/8-inch drive ratchet
• 1/2-inch drive breaker bar
• 1/2-inch drive torque wrench rated 20-150 ft-lbs
• Electronic parking brake service scan tool (specialty)
• Disc brake piston compression tool (specialty)
• Flat-blade screwdriver
• Small wire brush
• Caliper hanger hooks
• Rubber mallet
• M8 x 1.25 rotor removal bolts
• Floor jack rated 3-ton minimum
• Jack stands rated 3-ton minimum
• Wheel chocks
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Rear ceramic brake pad set - Qty: 1
• Rear ventilated brake rotors - Qty: 2, replace in pairs
• Rear brake pad hardware kit - Qty: 1
• Silicone ceramic brake lubricant - Qty: 1
• Aerosol brake cleaner - Qty: 2 cans

The parts aisle is open with matched rear pads, rotors, kits and hardware for your Ascent. A complete matched kit is the easiest route for a first brake job. Nobody enjoys discovering a missing clip after both wheels are off.

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📋 Before You Begin

• 📋 Park on level, solid ground and place the transmission in Park.
• 📋 Chock both front wheels securely.
• 📋 Release the electronic parking brake before lifting the vehicle.
• 📋 Switch off Auto Vehicle Hold if it is active.
• 📋 Connect the electronic parking brake service scan tool and select the maintenance or pad-replacement function.
• 📋 Wait for confirmation that both rear actuators are fully retracted.
• 📋 Open the hood and check the brake-fluid reservoir. Remove a little fluid if it is already at the maximum line.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Enter Electronic Parking Brake Maintenance Mode

• Connect the electronic parking brake service scan tool to the diagnostic port below the dashboard.
• Turn the ignition on without starting the engine.
• Select Subaru > Ascent > Parking Brake > Maintenance Mode, or the equivalent pad-replacement command displayed by your tool.
• Follow the prompts until the tool confirms that both parking-brake actuators are retracted.
• If the operation fails, stop and diagnose the fault before removing the calipers.

Step 2: Loosen the Rear Wheel Nuts

• Use the 19mm socket and 1/2-inch drive breaker bar to loosen each rear wheel nut approximately one-half turn.
• Do not remove the nuts while your Ascent is still on the ground.

Step 3: Raise and Support the Rear

• Use the floor jack rated 3-ton minimum at the approved rear lifting point.
• Place the jack stands rated 3-ton minimum beneath the rear support points.
• Lower the vehicle onto the stands and gently test that it is stable.
• Remove the wheel nuts with the 19mm socket, then remove both rear wheels.

Step 4: Remove the Rear Caliper

• Use the 14mm socket and 3/8-inch drive ratchet to remove the upper and lower caliper slide-pin bolts.
• Hold the slide pin with an appropriate wrench if it rotates with the bolt.
• Lift the caliper straight off the pads.
• Support it with a caliper hanger hook. Never hang it from the hose.
• Keep left and right parts separate.

Step 5: Remove the Pads and Caliper Bracket

• Pull the old inner and outer pads from the bracket by hand.
• Use the 17mm socket and 1/2-inch drive breaker bar to remove the two caliper-bracket bolts.
• Lift the bracket away and set it on a clean surface.

Step 6: Remove the Old Rotor

• Confirm that the electronic parking brake is released and remains in maintenance mode.
• Pull the rotor straight off the hub.
• If rust holds it in place, tap the rotor hat between the studs with the rubber mallet.
• If equipped with threaded removal holes, install the two M8 x 1.25 rotor removal bolts evenly until the rotor releases.
• Do not strike the wheel studs, bearing hub or rotor braking surface with a steel hammer.

Step 7: Clean the Hub and Prepare the New Rotor

• Use the small wire brush to remove rust and scale from the hub face.
• Make sure the hub is flat and clean. Rust trapped behind the rotor can create pedal pulsation.
• Clean both friction surfaces of an uncoated rotor with aerosol brake cleaner and a clean towel.
• Install the new rotor over the wheel studs.
• Temporarily install one wheel nut by hand to hold the rotor flat.

Step 8: Service the Caliper Bracket

• Use the flat-blade screwdriver to remove the old stainless pad clips.
• Clean the clip seating areas with the small wire brush.
• Install the new pad clips completely into the bracket.
• Remove each slide pin, wipe it clean and inspect its rubber boot.
• Apply a thin coating of silicone ceramic brake lubricant to the smooth slide-pin surfaces.
• Do not use petroleum grease because it can swell the rubber boots.

Step 9: Reinstall the Caliper Bracket

• Position the bracket over the new rotor and start both bolts by hand.
• Use the 17mm socket and 1/2-inch drive torque wrench to tighten the bracket bolts.
• Torque to 80 Nm (59 ft-lbs). howtoo.com

Step 10: Install the New Brake Pads

• Apply a very thin layer of silicone ceramic brake lubricant where each pad’s metal ears contact the new clips.
• Do not put lubricant on the pad friction material or rotor.
• Install the inner and outer pads into the bracket.
• Place any mechanical wear indicator in the same orientation as the original pad.
• Verify that both pads slide smoothly without excessive looseness.

Step 11: Compress the Caliper Piston

• Check that the parking-brake actuator remains fully retracted.
• Position the old pad across the piston face.
• Use the disc brake piston compression tool to press the piston slowly and straight into the caliper.
• Watch the brake-fluid reservoir while compressing the piston. Stop before it overflows.
• Do not twist the piston or use excessive force.
• If the piston will not move with light, steady pressure, stop. The actuator may not be fully retracted or the caliper may be seized.

Step 12: Reinstall the Rear Caliper

• Place the caliper over the new pads without twisting the brake hose.
• Start both slide-pin bolts by hand.
• Use the 14mm socket and 1/2-inch drive torque wrench to tighten both bolts.
• Torque to 27 Nm (20 ft-lbs). howtoo.com
• Confirm that both slide-pin boots are seated and not pinched.

Step 13: Repeat on the Opposite Side

• Repeat Steps 4 through 12 on the other rear wheel.
• Replace pads and rotors on both sides. Never replace rear friction parts on only one side.

Step 14: Reinstall the Wheels

• Remove the temporary wheel nut holding each rotor.
• Install the wheels and start all wheel nuts by hand.
• Snug the nuts in a star pattern using the 19mm socket.
• Raise the vehicle slightly with the floor jack rated 3-ton minimum, remove the stands and lower it fully.
• Use the 19mm socket and 1/2-inch drive torque wrench to tighten the wheel nuts in a star pattern.
• Torque to 120 Nm (88.5 ft-lbs).

Step 15: Exit Maintenance Mode

• Use the electronic parking brake service scan tool to select Parking Brake > Exit Maintenance Mode.
• Follow the displayed initialization instructions.
• Apply and release the electronic parking brake several times.
• Confirm that the parking-brake warning light switches off normally.

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✅ After Repair

• ✅ Check the brake-fluid level and secure the reservoir cap.
• ✅ With the engine off, press the brake pedal several times until it becomes firm.
• ✅ Start the engine and confirm that the pedal remains firm and does not sink.
• ✅ Inspect around both calipers for leaking fluid, pinched boots or twisted hoses.
• ✅ Test the electronic parking brake before moving the vehicle.
• ✅ Drive slowly in a safe area and verify normal braking before entering traffic.
• ✅ Follow the pad manufacturer’s bedding procedure. If none is supplied, make several moderate stops with cooling time between them.
• ✅ Avoid holding the brake pedal firmly while the brakes are extremely hot because that can transfer pad material unevenly.
• ✅ Recheck the wheel-nut torque after approximately 80-160 km.

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💰 DIY vs Shop Cost

Shop Cost: Approximately ₹35,000-₹65,000 for parts and labor, depending on local parts availability.

DIY Cost: Approximately ₹15,000-₹35,000 for pads, rotors and consumables, excluding the scan tool.

You Save: Approximately ₹15,000-₹30,000 by doing it yourself!

Labor pricing varies widely in Haryana, and imported Ascent parts may significantly affect the total. A workshop typically bills approximately 2-3 hours for this repair.

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