NHTSA looking into 2010-11 CX-9 brake booster failures...

interesting. i haven't had the issue myself, but will certainly keep an eye out for any recall/result.
 
Manufacturer: MAZDA MOTOR CORP

SUMMARY:
The Office of Defects Investigation (ODI) has identified 7 complaints alleging incidents of unexpected loss of power assisted braking in model year (MY) 2010 through 2011 Mazda CX-9 vehicles. Complaints allege experiencing incidents of the brake pedal suddenly feeling hard requiring increased effort to stop the vehicle. ODI previously investigated brake master cylinder leakage in MY 2008 Mazda CX-9 vehicles in PE11-026. Mazda identified a manufacturing process concern with the master cylinder primary plunger surface finish, that may result in leakage from the master cylinder into the brake booster. Analysis of the complaint data found that the master cylinder leak condition was generally detected by illumination of the brake malfunction indicator lamp and identified only 9 reports alleging any effect related to brake pedal feel or brake effectiveness. The investigation was closed April 9, 2012, based on the extremely slow leak rate associated with the master cylinder condition, the declining failure trend and the low probability that the condition could affect brake performance. In contrast to PE11-026, the complaints in the MY 2010 through 2011 Mazda CX-9 vehicles allege symptoms indicating possible loss of power assist to the brakes, including hard pedal, increased effort and reduced brake effectiveness. Several allege hearing a hissing noise during brake application. A Preliminary Evaluation has been opened to assess the scope, frequency and safety consequences of the alleged defect. The VOQs associated with the opening of this investigation are: 10523719, 10535301, 10535955 10546804, 10546841, 10493043, 10512943
 
Brakes good sofar, no issues and I have had OEM pads, aftermarket pads, and aftermarket rotors, 78K miles sofar.
 
My wife reported that her 2011 CX-9 was experiencing a hard brake pedal with a hissing sound when she applied the brake pedal. I drove the vehicle this afternoon and confirmed that there is a problem. I reported the issue to the dealer/service dept and scheduled an appointment for tomorrow. The service advisor mentioned that they have already replaced 3 brake boosters this month and they have one in stock. The vehicle is still under the factory warranty and the repair will be covered.
 
Update: The brake booster and master cylinder were both replaced under warranty today. The hard brake pedal and hissing sound is gone.

By the way, another symptom that I noticed before that is gone now is the following; engine on, vehicle in park, brake pedal depressed....now turn the engine off, the brake pedal would raise against foot pressure....weird I know.

I also had a new set of Yokohama Avid Envigor with alignment done, so we will see how they do. The stock Dueler's made it to 34K.
 
Thanks for the suggestion and I will look into doing so. I'm not sure if the dealer will report this issue.

At least the brake system got completely bleed....that's a (+)
 
I don't know if I'm starting to have the same issue with my 2012, but a every time a press the brake pedal it feels kind of soft and there is a hissing sound coming from the base of the pedal, sounds like a spray can. if I press hard or release it goes away. like not enough fluid. The reservoir is not empty but is below the MAX mark. The weird thing is that the brakes respond normal. Another thing I notice is that when I press and release the brake, even if it is on "P" the RPM fluctuates up and down a couple of times like when you are turning the steering. Definitely an issue. I am going the fill the fluid to the max but looks like there is some thing else going on.. Any thoughts?. Thanks
 
as your brake pads wear down the fluid level will naturally go down as the pistons in the calipers extend further. when new pads are installed the pistons in the calipers will be retracted pushing the fluid level back up.

power brakes and steering only exist while the engine is running of course (the new electric-assist steering is likely different) and i have seen rpms be very slightly affected from turning the steering wheel but i don't recall ever seeing rpms fluctuate from pumping on the brakes.

probably worth mentioning to the service advisor next oil change.
 
so i checked the mail today and got notice that mazda usa is conducting "special service program 93".

it is extending coverage for vacuum power brake booster unit in 2007-2013 cx-9s. vehicles produced form 8/24/06-4/26/13.

the warranty period is being extended to 7 years or 90k miles; if you have already exceeded that the coverage will last until 3/31/15.

coverage is transferable to new owners.

the symptoms are as previously mentioned: harder than normal brake pedal and/or hissing from driver-side foot area.
 
Good that Mazda do that for owners.
Was there a class action on this? Usually it takes a class action to force Honda/Toyota to do this.
 
Thanks for the comments!. It filled up the fluid to the MAX today but did not make any difference. However, the hissing is there and firmness is not consistent, but what is happening now is that when I stop at a traffic light and release the brake pedal or press hard on it the engine revs up and down like three time from 800 rpm to 1k rpm, if I release the brake and depress the accelerator it causes a hiccup which feels like the engine is going to stall. But if I don't press the brakes rpm, power, acceleration, etc. is all normal. I turned the AC today while pressing the brake and the engine clunked twice like bad gas. Scary in a city driving like NY!
 
Last edited:
ceric said:
Good that Mazda do that for owners.
Was there a class action on this? Usually it takes a class action to force Honda/Toyota to do this.
Click to expand...

I got the warranty notice too, and my 2009 GT CX9 w 83K applies.

I notice that when I start the car, i naturally depress the brake peddle and it is all the way to the floor...I have never had this happen with any other car in 30 yrs...is this symptomatic of the potential problem?

Finally, Mazda saw what happened when GM did not do the right thing and perform a recall, now 13-14 people are dead and they will settle in billions and spend billions more in damage control marketing...maybe mazda wised-up...
 
No Good!

tstex said:
I got the warranty notice too, and my 2009 GT CX9 w 83K applies.

I notice that when I start the car, i naturally depress the brake peddle and it is all the way to the floor...I have never had this happen with any other car in 30 yrs...is this symptomatic of the potential problem?

Finally, Mazda saw what happened when GM did not do the right thing and perform a recall, now 13-14 people are dead and they will settle in billions and spend billions more in damage control marketing...maybe mazda wised-up...
Click to expand...

http://www.bloomberg.com/news/2014-03-26/auto-regulator-has-51-people-tracking-250-million-cars.html
 
The GM inquisition touched a raw nerve with the manufacturers. They are bending over backwards to preempt potential political and financial fallout. (Spiders in the fuel line are the big scare with Mazda right now. Again).

But brakes are a serious matter. I received the brake program notice for my 2012 Touring. It's a great document. Extended coverage if you experience the issue. Free brake booster unit, replaced in about 2 hours, and a loaner vehicle. A reimbursement form if you paid to have this done already.

It's a really great sign Mazda is doing this. But it is short of a full recall, so they may still be liable for accidents caused due to the issue. Mazda is essentially waiting for a dangerous problem to occur, rather than preventing it.
 
i got the warranty notice in the mail the other day too. good to know it'll be covered if i have an issue.
 
To those who have gone to do the dealership regarding the Brake Booster issue, did the dealer validate the issue and state if they find nothing wrong, you'll be charged diagnostic fees, or did they just do the work, no questions asked?

Secondly, how long does it take to do this work? Something you can wait for, or ask for a loaner car?
 
I was given a loaner car that was covered by my extended warranty, as i was having a faulty seat belt replaced at the same time.

The lady at the dealership sent me the official paperwork on this "Safety Bulletin" This is the header of the 11 page document:

TO: Mazda Dealership General Managers, Service Managers, and Parts Managers
DATE: March 2014
SUBJECT: 2007-2013 CX-9 Power Brake Unit Warranty Extension Program SSP 93
Click to expand...

as far as rental cars:

RENTAL CAR INFORMATION
Mazda will authorize rental and service loaner vehicles on a limited basis. We are requesting dealer
understanding and partnership regarding rental and loaner vehicle utilization. Please make every
effort to utilize alternative transportation solutions in place of rental use.
Click to expand...

Their bolding, not mine

Once you start to notice this, TAKE IT IN IMMEDIATELY. Mine got progressively worse, harder to press the brakes, almost dangerous.
 
Last edited:
My CX 9 model 2013 is facing very hard brake and unable to stop.
Also when I press the brake pedal very hard until down I hear Hissing Sound...
what could be the problem? for the issue..
 
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