One problem related to brake master cylinder has been reported for the 2013 Volkswagen Jetta Sportwagen. The most recently reported issues are listed below.
Brake sometimes not working properly when the vehicle is on low speed less than 20 m/h. I feel the front brake is not working sometimes. I visit the car repair center and they said it is fine. But I read the same issue on the internet forum. They have changed the brake oil or master cylinder or brake rotor and disk but they just spent money and nothing improved. I need your help.