Master cylinder or brake booster failure on the 1997 Ford Expedition
1 fire 1 of the 7 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.
Only 5 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 master cylinder or brake booster failure gets reported
There are 7 reports of master cylinder or brake booster failure on the 1997 Ford Expedition, 5 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 92,000 miles. It is the 31st most-reported problem on this model year.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| — | — | 172,000 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, 1 a fire is 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 10 model years of this car. It shows up earliest on the 2003, at a median of 20,000 miles, and latest on the 2002 at 175,000 miles.
By volume the 2017 carries the most reports, with 35; the 1997 has 7. 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.
Dt: my wife was driving about 1/2 mile, came home and parked the truck. Within 30 minutes the truck was on fire and burned completely. Consumer put out the fire before the fire department arrived on the scene. The fire dept came out to make sure the fire was completely out, and they cut the hood open and noticed that the fire started in the master cylinder area. The truck was still sitting in front of the consumer's house. *ak *sb
I was braking and brake pedal sank to the floor. It turned out steel hydraulic brake lines had failed. I had all of them replaced in about 3/06 for a cost of $1000. I did not replace at the time the master cylinder to ABS lines. They failed on 11/23/2006 and I have retained them. If these components had failed at highway speeds it could have been potentially deadly. Note that my 1994 taurus sho had a similar failure. This vehicle has also had the transmission cooler steel lines fail and other severe undercarriage rust problems. *jb
I was braking and brake pedal sank to the floor. It turned out steel hydraulic brake lines had failed. I had all of them replaced in about 3/06 for a cost of $1000. I did not replace at the time the master cylinder to ABS lines. They failed on 11/23/2006 and I have retained them. If these components had failed at highway speeds it could have been potentially deadly. Note that my 1994 taurus sho had a similar failure. This vehicle has also had the transmission cooler steel lines fail and other severe undercarriage rust problems. *jb
Also reported on the 1997 Ford Expedition
Other suspension problem
Other body or interior problem
Other wheel or tire problem
Steering rack, gear or tie rod failure
Other electrical problem
Misfire or rough idle
How far this goes
This page is kept out of search results because 7 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 7 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 1997 Ford Expedition?
Across 5 owner reports that included an odometer reading, half were filed by 170,000 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 master cylinder or brake booster failure on the 1997 Ford Expedition?
7 reports have been filed with NHTSA, about 0.0 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