2017-2018 Genesis G80 Brake Job Guide: Symptoms, Costs and the Right Parts

By Core Brake Parts Tech Team — Circleville, OH warehouse

A brake job on a 2017-2018 Genesis G80 means front pads and rotors on four-piston fixed calipers, and rear pads and rotors on single-piston floating calipers, with a separate drum-in-hat parking brake inside the rear rotors. The single most important thing to get right is the rotor size, because it changes with the engine: the 3.8 V6 and the 5.0 V8 use different front rotors, and the 2018 G80 Sport 3.3T uses a larger rear rotor than both.

This guide covers how the G80 system is laid out, the symptoms that tell you a brake job is due, what to replace together, and what drives the cost, so you can order the right parts the first time.

How the 2017-2018 G80 Brake System Is Built

Genesis gave the G80 a large four-wheel disc system with ABS, Brake Assist and Electronic Brake-force Distribution. According to the official 2018 G80 specification sheet, every trim uses a four-piston caliper on a ventilated front rotor and a single floating-piston caliper at the rear. The Genesis launch material for the 2017 car describes the front calipers as four-piston fixed monobloc units. What changes between trims is rotor size and, on the Sport, the rear rotor design.

Two practical takeaways. First, a 3.8 and a 5.0 G80 of the same year do not share front rotors or front pads, so always shop by engine, not just by year. Second, the 2018 Sport is the only one of the three with a ventilated rear rotor, and its rear parts are not interchangeable with the 3.8 or 5.0. If you are not sure which engine you have, the badge on the trunk lid and your registration or VIN decode will tell you.

The parking brake is electronic, but on this generation it is not built into the rear caliper. The spec sheet lists it as an Electronic Parking Brake with a 7.48-inch drum-in-hat: small brake shoes that expand against a drum machined into the inside of the rear rotor hat. That matters during the job, as covered below.

Symptoms That Your G80 Needs a Brake Job

The G80 is a heavy sedan. Even the lightest 3.8 RWD weighs over two tons, and the V8 and Sport models are heavier still, so pads and rotors do real work on every stop. Watch for these signs:

• High-pitched squeal while driving. The pads carry a wear indicator that makes a warning sound when the friction material is close to the backing plate. Treat it as a notice that replacement is due, not a sound to live with.
• Grinding or metal-on-metal noise. The pad material is gone and the backing plate is cutting the rotor. At this point the rotors almost always need to be replaced along with the pads.
• Steering wheel shake or pedal pulsation when braking from highway speed. Usually uneven rotor thickness or uneven pad deposits on the front rotors. The big 13.6 and 14.2 inch fronts on this car make that vibration easy to feel.
• Pulling to one side. Often a sticking caliper piston or slide, a collapsed hose, or a contaminated pad on one side.
• Soft or low pedal. Check fluid level first. The G80 owner's manual says the level should sit between the MAX and MIN marks and warns that needing frequent top-ups can mean a leak.
• Rear grinding only after using the parking brake. Worn or rusted drum-in-hat parking brake shoes can drag inside the rear rotor hat.

Front vs Rear: What Wears and in What Order

Like most sedans, the G80 does most of its braking on the front axle, so front pads and rotors normally wear out before the rears. On the 3.8 and 5.0, the rear uses a solid rotor with a single-piston floating caliper, a simpler and lighter assembly than the front. Plan on the fronts first, and inspect the rears every time the fronts are done so you can schedule them before they reach the rotor.

The G80 was sold with HTRAC all-wheel drive as an option. AWD does not change which brake parts fit, but it does add weight, which the curb-weight figures above show, and that extra mass is one more reason to use quality pads and rotors rather than the cheapest option.

Check these while the wheels are off:

• Pad thickness on inner and outer pads (fixed four-piston calipers can wear unevenly if a piston is sticking).
• Rotor surface: deep grooves, a raised lip at the outer edge, heat spots or cracking.
• Caliper piston boots and, on the rear floating calipers, the slide pins and their boots.
• Rubber brake hoses for cracks or bulging.
• Rear parking brake shoe lining and the drum surface inside the rotor hat.

The Right Parts and What to Replace Together

For a proper brake job on a G80, replace pads and rotors together on the axle you are servicing. New pads on a worn or uneven rotor are the most common cause of noise and vibration after a DIY job, and the rotors on this car are large enough that machining an old one rarely makes sense.

• Pads: ceramic pads are the usual choice for a luxury sedan because they run quiet and keep the wheels clean. Browse ceramic brake pads or the full range of brake pads, and match the listing to your engine.
• Rotors: choose by diameter and trim, 13.6 in front for the 3.8, 14.2 in front for the 5.0 and Sport. See brake rotors.
• Hardware: new abutment clips and shims help keep a heavy car quiet. A brake hardware kit is inexpensive insurance.
• Calipers: only if a piston is seized, a boot is torn or a caliper is leaking. See brake calipers.
• Brake fluid: use only the fluid type specified in your owner's manual. The G80 manual warns that even a few drops of mineral-based oil can damage brake system parts, and that fluid left exposed to open air should never be used.

If you want everything in one order, shop all brake parts and filter by your G80.

How Hard Is the Job?

For someone with basic tools, a jack, and jack stands, the front pads and rotors on a G80 are a straightforward bolt-on job. The fixed four-piston front calipers do not slide, so each piston must be pushed back evenly and carefully. Keep the caliper supported so it never hangs on the brake hose, and clean the pad abutment surfaces before fitting new pads.

The rear is slightly more involved because of the drum-in-hat parking brake:

1. Make sure the electronic parking brake is released before you start, and chock the front wheels since the parking brake will not hold the car with the rear brakes apart.
2. Remove the rear caliper and bracket, then the rotor. If the rotor will not pull off, the parking brake shoes may be catching a worn lip in the drum. Follow the factory service procedure to back the shoes off rather than hammering the rotor.
3. Inspect the parking brake shoes and hardware, then fit the new rotor, pads and hardware.
4. Follow the factory service information for adjusting the shoes and bedding them to the new rotor hat.

Torque the caliper bracket bolts, caliper bolts and lug nuts to the values in the factory service manual; do not guess on a car this heavy. After the job, pump the pedal until it is firm before moving the car, then bed in the new pads with a series of moderate stops from medium speed.

What Drives the Cost of a G80 Brake Job

We do not quote a single number because the total depends on a few clear variables:

• Pads only vs pads and rotors. Rotors are the larger parts cost, and the 14.2 inch fronts on the 5.0 and Sport cost more than the 13.6 inch fronts on the 3.8.
• One axle vs both. Most G80s need fronts more often than rears, so a front-only job is the common case.
• Trim. The 2018 Sport has a larger, ventilated rear rotor, which costs more than the solid rear rotor on the 3.8 and 5.0.
• Extras. Seized calipers, worn parking brake shoes or a fluid flush add parts and labor.
• Labor. Doing it yourself removes labor entirely; a shop will charge per axle.

A Recall to Check Before You Start

While you have the car in the garage, check your VIN for open recalls. NHTSA recall 21V-160 covers 2017-2020 Genesis G80 sedans (along with 2015-2016 Hyundai Genesis sedans) for an ABS module that can develop an internal electrical short, increasing the risk of an engine compartment fire while parked or driving. The remedy is a replacement fuse rated at a lower amperage, installed free by a Genesis retailer. Warning signs include smoke, a burning or melting odor, and a malfunction or battery warning light. Until the remedy is done, park the car a safe distance from structures.

Frequently Asked Questions

Do the 2017 G80 3.8 and 5.0 use the same brake pads and rotors?

No. The 3.8 uses a 13.6 inch front rotor and the 5.0 uses a 14.2 inch front rotor, so the front pads and rotors differ. The rear rotor is 12.4 inches on both, but always confirm fitment by engine before ordering.

Is the 2018 G80 Sport different from the other trims?

Yes. The Sport shares the 14.2 inch front rotor with the 5.0 but uses a 13.0 inch ventilated rear rotor instead of the 12.4 inch solid rear rotor, so its rear pads and rotors are specific to that trim.

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

The 2017-2018 G80's electronic parking brake works through drum-in-hat shoes inside the rear rotor rather than a motor on the caliper piston, so the rear pad job is closer to a conventional one. Make sure the parking brake is released and follow the factory service information for the parking brake shoes.

Should I replace rotors every time I replace pads?

If the rotors are grooved, lipped, warped or below the minimum thickness stamped on them, yes. On a heavy car with large rotors, new pads on fresh rotors give the quietest, smoothest result.

What brake fluid does the G80 use?

Use only the brake fluid type listed in the Recommended Lubricants and Capacities section of your owner's manual, from a sealed container. Never mix in any mineral-based oil or fluid that has been left open.

Sources

1. Genesis Motor America - 2018 G80 3.8, 5.0 and 3.3T Sport specifications - rotor sizes, caliper types, drum-in-hat EPB, curb weights
2. Genesis Newsroom - 2017 G80 safety and convenience - four-piston fixed monobloc front calipers, Brake Assist, EBD, EPB with Auto Hold, HTRAC AWD
3. The Brake Report - ABS module recall of Genesis sedans - recall 21V-160, affected years, symptoms and fuse remedy
4. Genesis G80 Owner's Manual - Brake fluid - fluid level check, leak warning, fluid contamination warnings