Brake Master Cylinder problems of the 2008 Mazda CX9

Master cylinder leak causing the brake booster to go out as well. Suspension weak and rusty. Mazda refuses to address the problem.

My wife was driving our cx-9 with our kids on Saturday when the brakes failed. This prevented her from braking at a red light. There were no dash warning lights prior to the incident. The brake fluid was at a recommended level since the vehicle is well maintained. We towed the vehicle to the local Mazda dealer (where we originally purchased the vehicle). On removal of the brake booster the Mazda dealership found the brake booster failed because it was full of brake fluid. On closer inspection they found the brake master cylinder was cracked which led to the brake booster filling up and causing the brakes to fail. They said the brake master cylinder was not covered under the factory recall since this issue only happens to 2010-2011 model year cx-9's even though our 2008 cx-9 exhibits the same exact brake master cylinder defect. The brake booster was covered under the factory recall (from Mazda notes: perform manufacturers recall ssp93 power brake unit warranty). The only thing that prevented a major accident was this happened early on a Saturday morning with light traffic. If this would've happened Monday-Friday at the same time if would've been a severe accident since it's a very busy intersection during the work week. I truly believe this should be investigated for the 2008-2011 Mazda cx-9's.

The contact owns a 2008 Mazda Cx9. The contact stated that when the brake was depressed, the brake pedal would become stuck to the floorboard and caused an increase in stopping distance. The vehicle was taken to local mechanic whom inspected the vehicle and located the failure at the power brake booster master cylinder. The vehicle was not repaired. The VIN was not available. The approximate failure and current mileage was 190,000.

The contact owns a 2008 Mazda cx-9. The contact was driving 20 mph when the brakes were depressed and the vehicle failed to stop properly, and crashed into a gate. The crash caused no injuries and the police were not contacted. The same failure recurred on multiple separate occasions and without warning. The vehicle was taken to the dealer where the dealer confirmed that both the master cylinder and power booster were leaking brake fluid and needed to be replaced. The manufacturer was contacted. The vehicle was repaired. The failure mileage was 68,000 and the current mileage was 68,200. Updated 04/26/lj according to the repair invoice, the brake booster was leaking due to corrosion from brake fluid leaking from the master cylinder into the booster. The brake master cylinder and booster were replaced. Updated 04/27/12.

2008 Mazda cx-9 has a master cylinder machine problem. We replaced these items in August of 2011 and in less than 16000 miles we have the exact same failure. Nhtsa action number pe11026. Mazda has identified a problem with a manufacturing process dor the master cylinder primary plunger that could result in inappropriate surface finish. We are in the process of replacing these exact same parts today! this is an ongoing safety problem and the Mazda dealer told me the vehicle was unsafe to drive and the brakes could fail at any time. Our brakes not only had a soft feel but the distance to stop was greatly increased. We have had to replace the master cylinder and vacuum power assist twice in sixteen thousand miles at a cost of approximately $1300. 00.