The brake system seems to have lost its three press boost. After about 2 years, upon starting the car (2008 BMW 335xi auto) the press on the brake is stiff. It is stiff becauseit seems to have loss the 3 press boost. The boost that is supposed to protect the driver in case of engine failure. No other care I have owned leaks out its boost overnight. BMW admitted that the brake check valve was bad and replaced it with a newly designed part. I asked what this new design was and they could not tell me. I read online that many people have had this issue which starts with a stiff brake pedal then it degrades into the system not being able to start the car. BMW to their credit immediately found another part and loaned me a car in the meantime. The loaned car however did not show this stiff pedal issue. The new part they put in after about 1 month started to lose boost in the mornings off and on. I brought it in and they said this is normal? I"M worried that if I lose engine function going down a hill somewhere that they three press boost won't be their for me if we allow it to get worse. Suffice to say, once the engine starts you get the normal power assisted braking; however, this does not address the engine off three brake press safety requirement.

- Bothell, WA, USA