I encountered a common issue where a chime sound began to sound and the "check brake/hybrid system warning" was displayed on the dashboard. Car would then lose power and brake pedal would go to the floor.

I was able to pull over and re-start the car, however the warning appears after a few minutes. Was able to safely get the vehicle to a safe location only because I was less than a mile from said location.

Numerous occurrences of this failure are reported here:

https://www.carproblemzoo.com/hyundai/sonata/2013/service-brakes-problems.php

Anyone encountering this issue contact hyundaiusa.com and get a case number. I plan to tow the car to the nearest dealership. Already got a case and requested escalation

This issue has class-action lawsuit written all over it - which a similar suit forced Hyundai's hand in repairing defective engines - this is a serious safety issue much worse.

I bought this car in April, 2013. Although the car was otherwise fine, about a year later I noticed that, upon panic-braking suddenly, the car would tend to lock up and stop abruptly rather than pulse to a safe stop. I didn't think too much of it until it happened again. Please know that when this happens, my first instinct is to look in my rear-view mirror to make sure that I won't be pounded from the rear. I took the vehicle in for service and they said there was a leak in the brake lining. I took the car home, thinking that I was in the clear until the next time I had to panic-stop, and it happened again. This time they replaced the master cylinder. Yes, a couple months later, I had to take it in again, but, this time I also reported a banging in the brake pedal each time that I came to a slow stop at a light or stop sign.

They couldn't replicate the panic-stop lockup so they did nothing. They told me that the banging sound was a 'known' issue, but, they had no fix for the problem. By this time, my wife and I were becoming very concerned about our safety, but, our good friends at Hyundai didn't give a damn!

In August, 2014, I submitted a complaint with a VA Lemon Law attorney who proceeded to contact Hyundai about the issue. The attorney warned me that Hyundai and Kia were the 'WORST' manufacturers that they dealt with and that I should prepare for the long haul. About 45 days later, it was apparent that Hyundai's attitude was that I should pound sand. I had two choices, lose significant money by trading a car I had not planned to trade due to Hyundai's irresponsibility and utter disregard for human life, or, continue to drive the unsafe car while I pursued litigation as my only option. My wife and I had no choice but to trade the car for a safer model. Even that prospect gave us pause. Our only option was to trade the car in at a dealership because they had access to the 'public' service records and would surely check them out before they took our car in trade. Needless to say, we took a significant bath on the Hyundai.

I am writing this, and, I will continue to broadcast this message about Hyundai through every legal channel. We make a major purchase when we buy a vehicle and we measure our purchase decisions, in large measure, by how safe the vehicle is purported to be. When something unexpected happens, we should have an expectation that the manufacturer cares enough about its consumers to back them up, particularly with regard to safety issues. I can't state it clearly enough...Hyundai doesn't give a damn!

When the chips are down, Hyundai is not going to be there when you need them! Please consider very carefully how you vet your family's safety. If you love your family as much as I'm sure you do, please think twice before you put their lives in the hands of the likes of Hyundai.