PITSTOP - BRAKE CALIPER LEAK INSPECTION - This PITSTOP provides information related to a brake caliper fluid/oil substance found on some Kia vehicles, due to possible excess assembly oil applied during assembly.
full bulletin at NHTSA ↗2018 Kia Optima brakes problems
severe Owners of the 2018 Kia Optima have filed 8 NHTSA complaints about the brakes at roughly $450 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See brakes across all vehicles →
Complaints
8
Recalls
0
Avg fix
$450
| Model year | brakes complaints |
|---|---|
| 2014 Optima | 22 |
| 2015 Optima | 58 |
| 2016 Optima | 12 |
| 2017 Optima | 3 |
| 2018 Optima (this page) | 8 |
| 2019 Optima | 12 |
| 2020 Optima | 7 |
1crash
When does it fail?
Of the 8 brakes complaints filed for the 2018 Kia Optima, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
No new NHTSA brakes complaint has been filed on this vehicle in over 7 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering brakes on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
TECHNICAL SERVICE BULLETIN: IBAU SYSTEM REPAIR FOR NOISE AND AIR BLEEDING - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides the repair procedure for the Integrated Brake Actuation Unit (iBAU) system on some 2014-2019MY EV/Hybrid/Plug-In Hybrid vehicles listed (see table), which may exhibit a "honking" (Hissing) noise due to air remaining in the brake fluid system.
full bulletin at NHTSA ↗PITSTOP - INTEGRATED BRAKE ACTUATOR UNIT (IBAU) HONK NOISE - This Pitstop provides information regarding the 2017-2018MY Niro (DE P/HEV) and Optima Plug-in/Hybrid (P/HEV) vehicles, which may exhibit an intermittent ?squeaking? and/or ?honking? noise when applying the brakes rapidly. The ?Integrated Brake Actuator Unit? (IBAU) should NOT be replaced for this concern. An IBAU brake bleed should be performed.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 2 most recent
When reversing the brakes take 5 to 10 seconds to release, also the brake light stays on the entire time of this issue happening.
Front brake calipers seize and burning smell and smoke coming for front wheels. Have replaced the rotors, calipers and brake pads(twice) and it does not seem to fix the problem.
Had brakes trouble with your 2018 Kia Optima?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the brakes problem on the 2018 Kia Optima?
It's a meaningful issue. 8 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $450.
At what mileage does the brakes typically fail?
Based on the 8 complaints filed, brakes issues most often appear around 24,400 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $450 for brakes repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to brakes?
No active recalls currently cover brakes issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2018/Kia/Optima.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.