VACUUM BRAKE BOOSTER FAILURE

What NHTSA is examining

Odi upgraded the preliminary evaluation to conduct a full technical analysis, including testing.the testing and analysis shows that a torn diaphragm is a slow progressive type of failure.the tear propagates in a slow methodical manner and braking performance is similar to an untorn unit until the tear exceeds 1/2 inch.odi's testing indicates that tears greater than 1/2 inch required increased pedal effort.however, as the length of the tear increased beyond 1/2 inch, a hissing sound could be heard emitting into the passenger compartment where the master cylinder plunger passed through the firewall. Odi has determined that a safety-related defect trend has not been identified at this time and further use of agency resources does not appear to be warranted.the closing of this investigation does not constitute a finding that no safety-related defect exists.the agency reserves the right to take further action in the future if warranted by the circumstances.odi's complete technical analysis with test data is attached.

Vehicles under investigation