Master cylinder or brake booster failure on the 2014 Ford F-150
3 crashes 1 injury 4 of the 110 reports for this failure mention a crash, a fire, an injury or a death. Those are the owner's words on the complaint form, not a verified finding, and one report can mention more than one.
When master cylinder or brake booster failure gets reported
Owners of the 2014 Ford F-150 report master cylinder or brake booster failure at a median of 57,500 miles. A quarter of the reports come in before 40,000 miles and a quarter after 80,000 miles, from 86 reports that carried an odometer reading.
A part like this is normally expected to survive 92,000 miles. It is the 4th most-reported problem on this model year.
The mileage distribution
The reported range runs from 20,000 miles at the tenth percentile to 137,500 miles at the ninetieth, a spread of 116,400 miles across the middle 80% of reports.
When the reports scatter this far, the mileage is telling you about how these cars were driven more than about the part itself.
22% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 20,100 miles | 39,025 miles | 58,000 miles | 80,750 miles | 136,500 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
Of these reports, 3 a crash and 1 an injury are mentioned. Owners write their own complaints and the agency does not verify them, so read this as what the reports say happened rather than as a confirmed count.
Putting it right typically runs $450–$2,200 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 22 model years of this car. It shows up earliest on the 2005, at a median of 10,000 miles, and latest on the 1996 at 190,000 miles.
By volume the 2014 is the worst of them, which makes this a problem of this specific year rather than of the model as a whole.
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.
While driving on the interstate a warning for low brake fluid appeared on the dash. Shortly after I lost pressure in the brake pedal when trying to brake for slower traffic. I was able to pump the brakes to slow down enough and was able to get to a near by gas station. Their was no brake fluid left in the reservoir and after adding more brake fluid the reservoir drained within 5 minutes with no visible leak. The vehicle was towed to the dealership. The brake master cylinder had failed and drained all the brake fluid into the vacuum booster. I was lucky that I enough room to pump my brakes to gain control, otherwise this could have resulted in a major accident. This part should not fail in this manner nor at 18000 mile of vehicle life. The mechanic at the dealership claimed he has seen this issues on other f150s too.
Brake light came on while driving at 65 MPH. Immediately tested brakes and felt normal application. Three miles later approaching a four-way intersection, initiated second pedal application and brake pedal went to floor with no associated braking action. Used parking brake, gear down-shifting and road shoulder to avoid collision with other vehicles. Service inspection found master cylinder had leaked all fluid from reservoir into brake booster and into vacuum line. Replaced brake booster, master cylinder, vacuum check valve, and vacuum line.....updated 10/20/15 *bf
I started to pull out of my drive way and applied the brakes before entering the street. The brake pedal went completely to the floor failing to stop the truck I used the park bake to stop the vehicle . At this point I noticed the low brake fluid light had come on .I very carefully back the truck back into my drive way using the park brake to stop the vehicle again .I was lucky no cars were coming or we would have had a accident . I called the ford dealer who told me to call roadside assistance . The vehicle was towed to the ford dealership where they found that all the brake fluid had gone into the brake booster. I was informed that no replacement parts were available and they would put in a emergency order for them to speed things up. This leeds me to believe that ford is having real problems with these parts and this is not a isolated problem .
Also reported on the 2014 Ford F-150
Other powertrain problem
Other engine problem
Other visibility problem
Other brake problem
Other steering problem
Other electrical problem
How far this goes
Complaints are voluntary, so 110 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 master cylinder or brake booster failure happen on the 2014 Ford F-150?
Across 86 owner reports that included an odometer reading, half were filed by 57,500 miles. A quarter were filed before 40,000 miles and a quarter after 80,000 miles. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is master cylinder or brake booster failure on the 2014 Ford F-150?
110 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