general problems of the 2008 Subaru Tribeca

After starting the vehicle in sub freezing temperatures the brakes would not work. After applying extreme pressure it was found that the brake would operate but without any power assist. The error "er bb" was displayed on the instrument panel. After applying the brakes several times, the power assist started working and braking was normal again. This condition has repeated several times after the vehicle sits in sub freezing temperatures for a period of time. I believe this may be caused by a frozen check valve in the vacuum line to the brake booster.

Backing out of garage during cold weather below freezing, stepped on brake pedal and no response from the brake system. Was unable to stop car until I pumped brakes frantically many times. Left car out during below freezing weather 2 more times, same problem--no brakes. Vacuum assist for brakes would not work in below freezing weather. Took car to Subaru dealer, all 3 vacuum hose brakes replaced. Dealer states that each hose has a check valve in it for the vacuum system. Fortunately we discovered this problem at a very low rate of speed. No vacuum assist for the brakes makes this car virtually unstoppable at almost any speed. What if it would have been on a mountain road?? death would be eminent. I feel this should be under recall before someone is killed or maimed.