Brake Master Cylinder problems of the 2010 Hyundai Genesis

Tl the contact owns a 2010 Hyundai Genesis. The contact had to depress the brake pedal excessively in order to stop the vehicle. The failure occurred without warning. The vehicle was taken to suburban Hyundai (1814 maplelawn dr, troy, mi) where it was diagnosed that the master cylinder was defective and needed to be replaced. The manufacturer was notified of the failure and did not assist since the master cylinder was not part of a recall. The failure mileage was approximately 50,000.

When applying pressure to my brake petal, the car did not stop. I almost was involved in a few rear end collisons. It was very scary! dealership checked the brakes and nothing is wrong. I need to do a master cylinder change. Unfortunately, my car is no longer under warranty. Currently, it has 53,000 miles only. No recall for my vehicle.

When I pressed on the brake pedal, it felt mushy. Completely different from the firm braking the vehicle brakes had exhibited just a few minutes previously. I could feel the brakes trying to engage at the proper brake pedal placement but then I had to continue pressing the pedal because the brakes were not engaging. Only after I continued to apply pressure to the brake pedal toward the end of the pedal's range of motion did I finally feel the brakes begin to slow the car. After this first occurrence, since I was over 300 miles from home, I had to anticipate any braking I needed to do. I found that each time I needed to brake, if I pumped the brakes after the first initial pressing of the brake pedal, I could get the brake pedal to build up pressure so I would have close to the same braking 'feel' that I had had before this problem began. I returned home on Saturday. I did not drive the car on Sunday. On Monday, I took the Genesis to the Hyundai dealership. After almost two hours, they said they had identified the problem as the master cylinder. I had the master cylinder replaced on Tuesday. There was almost no change in the mushiness of the brake pedal. After searching the internet for possible causes I discovered Hyundai has had considerable complaints about fading and mushy brakes on their Genesis line of vehicles. It seems it all stems from the hydraulic electronic control unit module. So, with Hyundai knowing this, why did the service department of the abilene, TX dealership recommend a master cylinder replacement when, in my estimation, the first culprit should have been the abs module? I discovered this persistent issue with the Genesis vehicle on Wednesday, I have an appointment with the abilene TX Hyundai dealership on Thursday. I'll see how they respond.

Brakes failed - so master cylinder was replaced by dealer but brakes are still a bit spongy. Abs is not working quite right. Brake fluid had already been replaced 6 months earlier under recall, but brake control unit was not replaced. I am concerned that control unit should have been replaced and by other reports it seems Hyundai is very reluctant to pay for that. Car is still under warranty.