2018 Kia Optima service brakes problems
17 owner complaints filed with NHTSA name the service brakes on the 2018 Kia Optima — 7% of all complaints for this model year.
What owners report
“Purchased vehicle from a used car dealership. Had it a few months before brake pedal started losing pressure and going to floor. Had master cylinder replaced. A few months later, brake light started coming on when accelerating. New master cylinder had leaked into brake booster. Had master cylinder…”
filed Jul 2, 2026
“I turned the car off, it had difficulty turning back on and the brake pedal got really hard. I had to wait about 30-45 minutes and then I was able to get the car started and brake pedal back to normal and no lights. Recently, I left the car on to run into a shop real quick and come back out. When I…”
filed Jan 8, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Service Brakes problems in other Optima years
| Year | Reports | Share |
|---|---|---|
| 2020 Optima | 7 | 5% |
| 2019 Optima | 18 | 9% |
| 2017 Optima | 6 | 2% |
| 2016 Optima | 21 | 3% |
| 2015 Optima | 49 | 5% |
| 2014 Optima | 25 | 4% |
| 2013 Optima | 58 | 4% |
| 2012 Optima | 52 | 6% |
| 2011 Optima | 26 | 4% |
| 2010 Optima | 4 | 5% |
| 2009 Optima | 17 | 15% |
| 2008 Optima | 2 | 1% |
Other reported problem areas on the 2018 Kia Optima
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.