I’ve experienced a few issues with the brakes lately on the Ioniq. Specifically the conventional brakes, not regen.
About 4 times I’ve come up to traffic or required to stop at a junction and used the brake pedal to find the brakes very unresponsive, often having to really press the pedal with a fair bit of force to get a lethargic response from the brakes. It’s not a pressure issue as the pedal doesn’t feel stiff.
The car is less than a year old with 8527 miles on it.
Looking on the Ioniq Forums a few people who have experienced similar have suggested on a steep downhill slope with no other traffic pressing and holding the parking brake switch up until the car beeps and initiates full braking as this, according to posts, cleans off rust from the discs. But this sounds dodgy to me so want to get advice from others here