🔧 Optima - Rear Brake Pad Replacement

Replacing the rear brake pads requires removing both rear calipers, retracting the pistons, installing new pads, and lubricating the correct contact points. Rear pads must be replaced on both sides so braking remains balanced.

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

Assumption: Your Optima may have either a foot-operated parking brake or an electronic parking brake; both procedures are identified below.

---

⚠️ Safety & Precautions

• ⚠️ Support your Optima with jack stands. Never work beneath a vehicle supported only by a floor jack.
• ⚠️ Do not press the brake pedal while either rear caliper is removed.
• ⚠️ Brake dust can be harmful. Do not use compressed air to clean the brakes.
• ⚠️ Never allow a caliper to hang from its flexible brake hose.
• ⚠️ If equipped with an electronic parking brake, place it in service mode before retracting either piston. Forcing it inward can destroy the actuator.
• ⚠️ Keep brake fluid away from paint because it damages painted surfaces.
• ⚠️ Battery disconnection is not required. Maintain battery voltage if using an electronic parking-brake scan tool.

---

🔧 Required Tools

You'll need the following tools for this repair:

• Hydraulic floor jack (rated 2-ton minimum)
• Jack stands (rated 2-ton minimum)
• Wheel chocks
• 21mm lug-nut socket
• 14mm socket
• 3/8-inch drive ratchet
• 3/8-inch drive torque wrench (10-100 ft-lb range)
• 1/2-inch drive breaker bar
• Rear brake piston compression tool (specialty)
• Electronic parking-brake capable scan tool (specialty, if equipped)
• 12-volt battery maintainer (5-10 amp, if equipped with electronic parking brake)
• Small flat-blade screwdriver
• Brake-pad cleaning brush
• Brake-caliper hanger
• Plastic fluid syringe
• Safety glasses
• Nitrile mechanic gloves

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Rear brake pad set - Qty: 1 set; replace both sides
• Rear brake pad hardware kit - Qty: 1 set
• High-temperature silicone brake lubricant - Qty: 1 tube
• Non-chlorinated brake cleaner - Qty: 1 can
• DOT 3 or DOT 4 brake fluid - Qty: 1 small sealed container, only if adjustment is needed

---

📋 Before You Begin

• 📋 Park your Optima on firm, level ground. Put the transmission in Park and chock both front wheels.
• 📋 Open the hood and inspect the brake-fluid reservoir. If it is at the MAX line, remove a small amount with the plastic fluid syringe so it cannot overflow when the pistons retract.
• 📋 Release the parking brake completely before lifting the rear of the vehicle.
• 📋 Check the rear calipers for electrical actuator motors and wiring. Their presence identifies the electronic parking-brake system.
• 📋 If electronic parking brake equipped, connect the battery maintainer and use the scan tool’s Kia > Chassis > Electronic Parking Brake > Brake Pad Change Mode. Command both rear actuators to retract.
• 📋 If foot-operated parking brake equipped, no scan-tool service mode is needed.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Loosen the Rear Wheel Nuts

• Use the 21mm lug-nut socket and 1/2-inch breaker bar to loosen each rear wheel nut about one-half turn.
• Do not remove the nuts while the tires are supporting the vehicle.

Step 2: Raise and Support the Rear

• Use the hydraulic floor jack at the approved rear lifting point to raise your Optima.
• Position both jack stands beneath the approved rear side support points. Lower the vehicle gently onto them.
• Shake the vehicle lightly to confirm it is stable before approaching the brakes.

Step 3: Remove Both Rear Wheels

• Use the 21mm lug-nut socket and 3/8-inch ratchet to remove the wheel nuts.
• Remove both rear wheels and place them flat away from your work area.

Step 4: Inspect the Brakes

• Use the safety glasses, gloves, brake cleaner, and brake-pad cleaning brush to remove loose dirt without creating airborne dust.
• Inspect the brake hoses, calipers, and rotors for leaks, cracks, severe grooves, or blue heat spots.
• If either rotor is below its stamped minimum thickness, replace both rear rotors before installing the pads.

Step 5: Remove the First Caliper

• Use the 14mm socket and 3/8-inch ratchet to remove the upper and lower caliper guide-pin bolts.
• Lift the caliper away from the pads. Do not disconnect the brake hose.
• Support the caliper with the brake-caliper hanger. A caliper hanger is a hook that carries the caliper without stressing its hose.

Step 6: Retract the Caliper Piston

• If equipped with a foot-operated parking brake, place an old pad against the piston and use the rear brake piston compression tool to press the piston slowly and evenly into the caliper.
• If equipped with an electronic parking brake, verify the scan tool has fully retracted the actuator. Then use the rear brake piston compression tool to press the piston straight inward.
• Watch the brake-fluid reservoir as the piston moves inward. Use the plastic fluid syringe if the level approaches the top.
• Stop if the piston binds, tilts, or requires extreme force. This may indicate a seized caliper or an electronic actuator that is not fully retracted.
• Retract slowly to protect seals and ABS components.

Step 7: Remove the Old Pads and Hardware

• Remove the inner and outer pads by hand.
• Use the small flat-blade screwdriver to lift the stainless-steel pad clips from the caliper bracket.
• Note the position of the wear indicator before discarding the old pads.

Step 8: Clean and Lubricate the Bracket

• Use brake cleaner and the brake-pad cleaning brush to clean the pad-support areas on the bracket.
• Install the new brake pad hardware by hand. Confirm every clip sits fully against the bracket.
• Apply a very thin coat of high-temperature silicone brake lubricant where the pad tabs slide on the hardware.
• Apply a thin coat to the metal pad backs only where they contact the caliper or piston.
• Do not put lubricant on the rotor or pad friction surfaces.

Step 9: Inspect the Guide Pins

• Pull each guide pin from its rubber boot by hand, one at a time, so their positions are not mixed.
• Wipe the pins clean and inspect for rust, pitting, or damaged boots.
• Apply a thin coat of high-temperature silicone brake lubricant and reinstall each pin by hand.
• Confirm both pins slide smoothly and the rubber boots seal around them.

Step 10: Install the New Pads

• Install the inner and outer pads into the bracket by hand, matching the original wear-indicator position.
• Check that the pads slide freely in the hardware without excessive looseness.
• Never grind the friction material to make a pad fit.

Step 11: Reinstall the Caliper

• Remove the brake-caliper hanger and place the caliper over the new pads.
• Make sure the brake hose is not twisted.
• Start both guide-pin bolts by hand to prevent cross-threading.
• Use the 14mm socket and torque wrench to tighten the guide-pin bolts to Torque to 22-32 Nm (16-24 ft-lbs).

Step 12: Repeat on the Opposite Side

• Use the same listed tools and repeat Steps 4 through 11 on the other rear brake assembly.
• Replace rear pads as a complete axle set, never on only one side.

Step 13: Reinstall the Wheels

• Install each wheel and start all wheel nuts by hand.
• Use the 21mm lug-nut socket and 3/8-inch ratchet to snug the nuts in a star pattern.
• Use the hydraulic floor jack to raise the vehicle slightly. Remove the jack stands and lower the vehicle until the tires touch the ground.
• Use the 21mm lug-nut socket and torque wrench to tighten the wheel nuts in a star pattern to Torque to 107-127 Nm (79-94 ft-lbs).

Step 14: Restore the Electronic Parking Brake

• If equipped with an electronic parking brake, use the scan tool and select Kia > Chassis > Electronic Parking Brake > Brake Pad Change Mode > Finish.
• Command the actuators to apply and release. Clear only electronic parking-brake faults caused during the repair.
• Disconnect the battery maintainer after completing service mode.
• If foot-operated parking brake equipped, slowly apply and release the parking-brake pedal several times.

---

✅ After Repair

• ✅ Before moving your Optima, press the brake pedal repeatedly until it feels firm. The first few presses may travel farther than normal.
• ✅ Check the brake-fluid reservoir and set the level between MIN and MAX using fresh DOT 3 or DOT 4 fluid. Do not overfill it.
• ✅ Apply and release the parking brake several times. Confirm the warning light turns off after release.
• ✅ Inspect both rear calipers for brake-fluid leaks and verify both brake hoses remain untwisted.
• ✅ Test the brakes at walking speed in a safe, traffic-free area before normal driving.
• ✅ Bed in the pads with 8-10 moderate stops from approximately 50 km/h to 10 km/h. Allow cooling time between stops and avoid holding the brake pedal while stationary immediately afterward.
• ✅ Avoid emergency-style stops for the first 300 km unless required for safety.
• ✅ Recheck wheel-nut torque after approximately 80-100 km.

---

💰 DIY vs Shop Cost

Shop Cost: ₹8,000-₹16,000 (parts + labor)

DIY Cost: ₹3,000-₹7,500 (parts only)

You Save: ₹5,000-₹8,500 by doing it yourself!

Local labor rates and parts pricing vary. This repair takes a shop approximately 1-1.5 hours.

---

🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.