2017-2019 Genesis G90 Front vs Rear Brakes: What Wears First and What to Replace

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2017-2019 Genesis G90, the front pads usually wear out first because the front axle does most of the stopping. That is not guaranteed, though. The G90 uses electronic brake proportioning and an electric parking brake on the rear calipers, so the rears can catch up or even wear faster. Measure both axles before you buy parts, and always replace pads as a full axle set.

How the G90 Brake System Is Laid Out

The first-generation G90 is a large rear-wheel-drive-based luxury sedan, offered with a 3.3-liter twin-turbo V6 or a 5.0-liter V8 and available all-wheel drive. It has disc brakes at all four corners. Each rear caliper also carries the actuator for the Electronic Parking Brake (EPB), which replaces the old pedal or hand lever with a switch on the console. The owner's manual lists brake fluid conforming to DOT 3 or DOT 4 (FMVSS 116), with a system capacity of about 0.74 to 0.85 US quarts.

The car also runs staggered tires from the factory: 245/45R19 in front and wider 275/40R19 in back. That matters for two reasons. You cannot rotate tires front to rear the usual way, and Genesis says brake pads should be inspected whenever the tires are rotated. If your shop only rotates side to side, or skips rotations because of the staggered setup, the brakes may not get looked at as often as they should.

Front vs Rear: Which Wears First and Why

When you brake, the car's weight shifts forward onto the front tires, so the front brakes do most of the work. On older cars with a mechanical proportioning valve, rear brake pressure was cut by 20 to 40 percent depending on the application, and front brakes typically wore two to three times faster than the rears. Automotive reference AA1Car explains this in its brake balance article.

The G90 works differently. It uses electronic brake force distribution through the ABS and stability control system. The same reference notes that on vehicles with electronic brake proportioning, the rear brakes may actually wear out faster than the fronts, because the system can let the rear axle do a larger share of the braking than a fixed valve would.

The practical takeaway: plan on the fronts going first, but do not assume it. Pull a wheel at each end and measure the pads.

Symptoms and How to Check Each Axle

Genesis fitted pad wear indicators. The manual explains that when the pads are worn and new ones are needed, you will hear a high-pitched warning sound from the front or rear brakes. It may come and go, or it may happen every time you press the pedal. Genesis also notes that a light squeal on the first few stops in some weather is normal and does not mean the brakes have a problem.

• Steady high-pitched squeal while braking: the wear indicator is touching the rotor. Find out which axle it is coming from.
• Grinding or scraping: the friction material is gone and metal is contacting the rotor. The rotors almost certainly need replacing.
• Vibration in the steering wheel under braking: usually uneven front rotor thickness or pad deposits on the rotor.
• Pulsation felt in the seat or pedal, not the wheel: often points to the rear rotors.
• Parking Brake and Brake Fluid warning light on with the EPB released: the manual says this can mean low fluid. Fluid drops as pads wear, so a low reservoir with no leak is often a sign of thin pads. Genesis says to check all brake components for leaks if the level is low.
• EPB warning light: can point to a problem with the parking brake actuator or its system. The manual notes it can also come on along with the ESC light when stability control is not working properly.

To check the pads, look through the wheel spokes at the outer pad, or pull the wheel for a clear view of both pads. Genesis also tells owners to check the discs for runout and wear and the calipers for fluid leaks during inspection. Compare the inner and outer pad on each side. Uneven wear between them usually means a caliper slide or piston is sticking, and a new set of pads will not fix that on its own.

What to Replace, and What to Replace With It

Genesis is clear on one point: always replace pads as a complete front or rear axle set. Never do just one side.

Front axle

If the front pads are low and the rotors are smooth and within the thickness limit cast or stamped on them, pads alone may be enough. Most shops replace the rotors on a heavy car like the G90, because a worn rotor has less mass to absorb heat, and new pads bed in faster on a fresh surface. We carry Bendix ceramic front brake pads for the 2017-2019 G90, and you can compare rotor options in our brake rotors collection.

Rear axle

Rear pads on the G90 need more care because of the EPB. The electric actuator holds the rear pistons out, so the system must be put into its service or maintenance position with a compatible scan tool before the pistons are pushed back. Forcing the piston against a locked actuator can damage the caliper motor or gear drive. After the job, the EPB is applied and released again so it can set its position against the new pads.

While you are in there

• Hardware: new abutment clips and fresh caliper-slide grease help prevent noise and uneven wear. See our brake hardware kits.
• Fluid: top off only with DOT 3 or DOT 4, as the manual specifies. If the fluid is dark or the car has not had a flush in years, a flush during a brake job is a sensible add-on.
• Calipers: if a caliper is leaking or a slide is seized, replace it. Rear calipers on this car include the EPB actuator, so confirm the correct part before ordering from our brake calipers section.
• Wheels: torque lug nuts to the 79 to 94 lbf-ft range Genesis lists, in a star pattern. Uneven lug torque is a common cause of rotor vibration after a brake job.

How Hard Is the Job?

A front pad and rotor job on the G90 is a normal driveway task for someone who has done brakes before: raise the car safely, remove the caliper, replace the parts, and bed in the new pads. The fronts have no parking brake mechanism, so the pistons compress the usual way.

The rears are where DIY jobs go wrong. Without a scan tool that can retract the EPB, you should not attempt the rear pads. If you do not have one, a shop visit for the rear axle alone is reasonable while you do the fronts yourself.

Know your car before ordering. Front brake parts can differ between the 3.3T and 5.0 models, so match parts by year, engine, and drivetrain. Use our brake pads catalog to filter by vehicle.

Recalls and Known Issues

A check of NHTSA recall records for the 2017, 2018, and 2019 G90 shows no brake system recalls. The recalls listed for these years cover the turbocharger oil feed on 3.3T models, water entering the starter solenoid, and windshield primer on some 2018 cars. None affect the brakes. You can confirm open recalls for your specific car by entering your VIN on nhtsa.gov.

Frequently Asked Questions

Do the front brakes on a Genesis G90 always wear out before the rears?

Usually, but not always. Weight transfer makes the fronts work harder. Electronic brake force distribution, stability control, and parking brake drag can all put extra wear on the rears. Measure both axles before buying parts.

Can I replace just the front pads and leave the rears?

Yes, if the rear pads and rotors are still in good condition. Genesis only requires that pads be replaced as a complete axle set, meaning both sides of the same axle.

Do I need a scan tool to change the rear pads on a G90?

Plan on it. The rear calipers carry the Electronic Parking Brake actuators, which must be retracted electronically before the pistons can be pushed back. Forcing them can damage the actuator.

What brake fluid does a 2017-2019 G90 use?

The owner's manual lists hydraulic brake fluid that meets DOT 3 or DOT 4 (FMVSS 116). Do not use DOT 5 silicone fluid or any fluid not on that list.

Why is my G90 squealing only on the first stop of the morning?

Genesis notes that some weather and driving conditions cause a brief squeal on light, first applications, and that this is normal. A squeal that stays or gets worse points to the wear indicators, and the pads need checking.

Should I replace rotors with the pads?

If the rotors are scored, below their minimum thickness, or causing vibration, yes. On a heavy car that sees highway speeds, many owners replace rotors with every pad set for smoother, quieter stops.

Sources

1. Genesis G90 Owner's Manual (Genesis Motor America) - disc brake wear indicator, axle-set replacement, EPB operation and warnings, DOT 3/DOT 4 fluid spec and capacity, staggered tire sizes, lug nut torque, severe-use brake inspection
2. AA1Car - Brake Balance and Electronic Brake Proportioning - weight transfer, 20 to 40 percent rear pressure reduction, front wear rates, rear wear with electronic proportioning
3. NHTSA recall records - 2017 Genesis G90 - recalls on file for 2017, none brake-related
4. NHTSA recall records - 2019 Genesis G90 - recalls on file for 2019, none brake-related