Kia Stinger (2018-2023) Brake Fluid Type and Flush Interval

By Core Brake Parts Tech Team — Circleville, OH warehouse

The Kia Stinger uses glycol-based hydraulic brake fluid. The 2019 Stinger owner's manual lists FMVSS 116 DOT 3 or DOT 4, and a system capacity of 0.42 US quart (0.395 liter). Kia's normal schedule calls for an inspection every 24 months or 12,000 miles rather than a fixed replacement mileage, so on a car that is driven hard, a full flush every 2 to 3 years is the practical rule, and DOT 4 is the better of the two choices.

What the Kia Stinger Brake System Uses

Every Stinger has four-wheel disc brakes, ABS and stability control, and all of them share one hydraulic circuit fed from the reservoir under the hood. What changes between trims is the hardware at the corners. According to Kia's 2023 specifications, the four-cylinder GT-Line uses single-piston calipers on 13.6 inch front and 13.0 inch rear discs, with only the fronts vented. The twin-turbo V6 GT2 gets Brembo brakes: four-piston front calipers, two-piston rears, and vented 13.8 inch front and 13.4 inch rear discs.

The fluid is the same on both. The Brembo system does make the fluid work harder, though, because a 368 hp car that sees back-road or track use puts far more heat into the calipers, and that heat soaks into the fluid.

DOT 3 or DOT 4: Which One to Buy

Both fluids are allowed in the 2019 manual, but they are not equal. The federal standard, FMVSS 116, sets the minimum boiling points each grade must meet:

The "wet" number is the one that matters on a car a few years old, because it describes fluid that has already picked up moisture. DOT 4 holds a higher margin in both states, which is why it is the sensible pick for a Stinger, especially a GT or GT2 with the Brembo package. Check the lubricants table in your own year's owner's manual before you buy, since Kia can revise the listed spec between model years.

Two rules from the Kia manual apply no matter which grade you use: never mix different types of fluid, and never use fluid from a bottle that has sat open for a long time. Do not use DOT 5 silicone fluid; it is a different chemistry and is not what the Stinger system was filled with.

Why the Fluid Needs Changing at All

Glycol brake fluid is hygroscopic. Brembo explains that over time it absorbs moisture from the air through the porosity of the brake hoses, and that the boiling point of fluid that is three years old can be significantly lower than new fluid. Brembo's general recommendation is replacement every 2 to 3 years.

When the boiling point drops far enough, hard braking can boil the fluid in the calipers. Vapor compresses where liquid does not, so the pedal goes soft or sinks toward the floor right when the brakes are hottest. Moisture also promotes internal corrosion in calipers, lines and the ABS unit, which is an expensive part to replace.

Kia's schedule treats brake fluid as an "inspect" item every 24 months or 12,000 miles, meaning inspect and replace if needed. A shop can check it with a moisture or boiling-point tester; dark, cloudy fluid is another sign it is overdue. For a Stinger used as intended, with spirited driving or the occasional track day, treat 2 years as the replacement point, and flush before any track event.

Symptoms of Old or Low Brake Fluid

• Soft or spongy pedal, or a pedal that gets longer after repeated hard stops.
• Brake warning light on. The Stinger's brake and brake fluid warning light comes on when the reservoir level is low.
• Low reservoir level. Kia notes the level falls slowly as the pads wear, which is normal. A fast drop, or a need to top off often, means a leak and needs inspection right away.
• Dark fluid. Fresh fluid is clear to amber. Brown or black fluid has absorbed moisture and debris.
• Wet spots or crust at a caliper, hose or line fitting.

Kia's manual also repeats NHTSA's corrosion warning for cars in salt states: wash the underbody through winter, watch for fluid loss and a spongy pedal, and replace brake pipe that shows severe scaling or flaking. If you find a leak, replacement brake lines and brake hoses come before any fluid service.

How to Check and Flush the Fluid on a Stinger

1. Park on level ground. Wipe the reservoir cap and the area around it clean before opening it, as the manual directs, so dirt cannot fall in.
2. Read the level against the MIN and MAX marks on the side of the reservoir. Add only the specified fluid, up to MAX.
3. For a flush, bleed each caliper with fresh fluid from a sealed bottle until clean fluid comes out, keeping the reservoir from running dry so no air reaches the ABS unit. Follow the bleed sequence in the factory service manual for your model year.
4. The Stinger has an electronic parking brake. If you are also doing rear pads, the EPB caliper has to be retracted with a scan tool or the service procedure, not forced back by hand.
5. Protect the paint. Kia warns that brake fluid damages body paint, so rinse any spill right away, and flush your eyes with water and see a doctor if fluid gets in them.

The system holds under half a quart, so one liter of fluid is plenty for a complete flush with extra to spare. A pressure bleeder or a two-person pedal bleed both work. This is a moderate DIY job; most owners who can change their own pads can flush the fluid.

What to Replace at the Same Time

A fluid flush is a natural time to look at the rest of the system, since the wheels are already off. Check pad thickness, disc surface and runout, and caliper seals for weeping, all of which Kia lists under its brake inspection items.

For the Brembo-equipped Stinger GT and GT2, we carry direct-fit upgrades: EBC Redstuff ceramic front brake pads for the Stinger 3.3L twin turbo with a matching EBC Redstuff rear pad set, and DBA 4000 Series T3 slotted front rotors for Brembo-equipped Stingers. Owners who track the car can step up to GiroDisc slotted front rotors for the Stinger GT. If you are upgrading pads and rotors for harder driving, fresh DOT 4 fluid should go in at the same time, since better friction material only helps if the fluid can take the heat. Browse the full range of brake pads and brake rotors as well.

Frequently Asked Questions

What brake fluid does a Kia Stinger take?

The 2019 Stinger owner's manual specifies hydraulic brake fluid meeting FMVSS 116 DOT 3 or DOT 4. DOT 4 has higher minimum boiling points and is the better choice, especially on Brembo-equipped cars. Confirm the spec in your own year's manual.

How often should I change the brake fluid in my Stinger?

Kia's normal schedule inspects the fluid every 24 months or 12,000 miles and replaces it as needed. Brembo recommends replacement every 2 to 3 years because the fluid absorbs moisture. On a car driven hard, change it every 2 years and before any track day.

How much brake fluid does a Kia Stinger hold?

The 2019 owner's manual lists 0.42 US quart (0.395 liter). A one-liter bottle covers a full flush with room for proper bleeding.

Can I mix DOT 3 and DOT 4 in my Stinger?

Kia's manual says never to mix different types of fluid. If you are switching from DOT 3 to DOT 4, do a complete flush so the system holds only one fluid.

Why does my Stinger brake fluid level keep dropping?

A slow drop is normal as the pads wear, because the caliper pistons move out and hold more fluid. A quick drop or a need to top off often points to a leak, and the car should be inspected before it is driven further.

Sources

1. 2019 Kia Stinger Owner's Manual - DOT 3 or DOT 4 spec, 0.42 qt capacity, 24 month/12,000 mile inspection, checking procedure, warnings, EPB, NHTSA corrosion notice
2. 49 CFR 571.116 (FMVSS 116), Cornell Legal Information Institute - minimum dry and wet boiling points for DOT 3 and DOT 4
3. Brembo - Brake Fluid for Cars - moisture absorption, boiling point decline, 2 to 3 year replacement
4. Kia Media - 2023 Kia Stinger Specifications - rotor sizes, caliper piston counts, Brembo on GT2, electronic parking brake