Loss of braking on the 2008 Mazda CX-9
Only 4 reports for this mode came with an odometer reading, which is too few for percentiles to mean anything. The page is here because someone linked to it; treat the figures as anecdotes, and see the full report for this year instead.
When loss of braking gets reported
There are 4 reports of loss of braking on the 2008 Mazda CX-9, 4 with a mileage attached. That is too few to place the failure on the odometer with any confidence.
A part like this is normally expected to survive 78,000 miles. It is the 16th most-reported problem on this model year.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| — | — | 87,500 miles | — | — |
Read the 10th percentile as “one report in ten arrived this early”. Exact figures are shown in this table because it is the table of record; everywhere else on the site they are rounded to the precision the sample can carry.
What a percentile can and cannot tell you here
These five numbers describe the readings owners gave, in order. The median is the middle one: half the reports arrived below it. The 10th and 90th are the edges of the bulk of the distribution, and the distance between them is the part worth reading. A tight spread — say 70,000 to 95,000 miles — points at something that wears out on a schedule, and the schedule is knowable. A wide one, 20,000 to 190,000, points at a fault that hits some cars and never troubles others, which means the mileage on the listing in front of you tells you very little about your odds.
What these figures are not is a survival curve. Every reading here comes from a car whose owner filed a complaint, so the sample contains only failures: it cannot say what share of the fleet made it past 150,000 miles untouched, because those owners had nothing to report. Nor is the mileage the moment of failure — it is the odometer reading as recalled at the time of filing, which may be weeks later and is sometimes rounded to the nearest ten thousand by the person typing it.
Percentiles are shown at all only once 8 readings exist for the vehicle and mode. Below that the middle of a handful of numbers is noise wearing a decimal point, so the figures are withheld rather than dressed up.
What happens, and what it costs
Putting it right typically runs $400–$3,000 at an independent US shop. That range is an editorial estimate held in this site's failure-mode catalogue, not a figure from NHTSA, and it is a repair cost rather than a diagnosis cost.
This mode is classified as critical, which means a failure can leave the car unable to stop, steer, or stay out of the way of traffic. It is weighted accordingly in the risk score.
The same failure on other years
The same failure is reported on 5 model years of this car. It shows up earliest on the 2010, at a median of 40,000 miles, and latest on the 2007 at 105,000 miles.
By volume the 2012 carries the most reports, with 18; the 2008 has 4. A mode that appears across most years of a model is usually a design choice rather than a bad batch.
If one year stands out to the left, that is the year to avoid; if the whole line sits at a similar mileage, this is wear rather than a defect in one production run.
Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens
What owners wrote
Verbatim from NHTSA complaint narratives, trimmed for length. The mileage is the one the owner gave.
Tl* the contact owns a 2008 mazda cx9. The contact stated that while driving 25 MPH, the brakes failed to stop the vehicle. The contact was able to safely pull over. The vehicle was taken to the dealer for diagnosis where it was stated that the brake booster needed to be replaced. The vehicle was not repaired and the manufacturer was notified. The approximate failure mileage was 40,000.
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…
Also reported on the 2008 Mazda CX-9
Control arm, ball joint or bushing failure
Other suspension problem
Airbag inflator rupture
CV axle or driveshaft failure
Differential or transfer case failure
Master cylinder or brake booster failure
How far this goes
This page is kept out of search results because 4 reports is not enough to publish percentiles from. It stays reachable because somebody looking at this exact car would rather see the reports than be told there are none.
Complaints are voluntary, so 4 is a floor and not a count of affected cars. Mileages are typed in by owners and cluster on round numbers. And the mode itself is assigned by software reading the complaint text, which is reliable in bulk and fallible one report at a time.
Questions this page answers
At what mileage does loss of braking happen on the 2008 Mazda CX-9?
Across 4 owner reports that included an odometer reading, half were filed by 90,000 miles. A quarter were filed before — and a quarter after —. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is loss of braking on the 2008 Mazda CX-9?
4 reports have been filed with NHTSA, about 0.2 per 1,000 vehicles. Complaints are voluntary, so this is a floor rather than a count of affected cars.
What this is and is not. These are the mileages at which owners chose to complain to a federal agency, which is not the same as the mileage at which the part fails on every car. It skews toward failures that happened outside warranty, cost real money, or frightened someone. It is still the only public dataset that carries failure mileage at all, and the shape of a few hundred readings is informative even when a single one is not. Methodology · JSON · this failure on other cars
Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed