(August 16, 2011) The  National Highway Traffic Safety Administration says it is investigating a number of reports over brake problems with model year 2008 Mazda CX-9 crossover vehicles.

The agency says Mazda has sent data to its Office of Defects Investigation indicating a high frequency of warranty claims and complaints regarding the brakes with vehicles’ brakes during the period from the first quarter of 2008 to the third quarter of 2010.

In most cases the main cause was brake fluid leaking from the master cylinder into the vacuum booster, which is part of the power-braking system.

When brake fluid leaks into the booster it may reduce the brakes’ effectiveness and result in longer stopping distances, which can increase the risk of a crash.

The inquiry affects about 37,000 vehicles. The agency said it knows of no reports of accidents, injuries or fatalities related to the problem.