Brake Pedal Slowly Sinks to Floor After Coming to a Standstill?
I own a 2012 Kia Sorento EX. It’s been quite good all these years.
Here’s the issue: When ever I brake and come to a standstill ( For instance at a traffic light stop) the brakes work very well as they should. But as I’m stationary, resting my foot on the firm brake pedal, slowly the pedal starts going soft and slowly sinks to the floor. Simultaneously the car just starts creeping forward. I’ve bumped into a few cars this way. Thankfully no damage for either driver. Only way to remain stationary at this point is to press the brake pedal to the floor or lift pedal and quickly press down again until the same happens.
How it first started: It appeared first when my ABS module started malfunctioning when I hit a huge pothole with my left-front wheel while braking downhill. There was this rrrr-ing noise and the brakes stopped working for a brief moment downhill. (Very scary)
Fixed but came back: The Manufacturer authorized repair center in our country completely replaced the ABS unit & replaced the brake fluid. But after just 2 weeks of the car’s brakes working good as new, the issue came back!
The master cylinder has no leaks and the break fluid is clear. The car still brakes very strong. The issue only arises when stationary.
Does anyone have any idea what’s going on?
I found this thread and the OP seems to have experienced exact symptoms. And apparently replacing Master Cylinder has worked.