There are 4 stored owner reports matching the brakes leading-label group for the 2004 Mercury Mountaineer in our NHTSA-sourced dataset. These are unverified consumer reports and may not reflect confirmed defects.
This group counts stored reports whose component label starts with one of this site's matching prefixes, ignoring case. Each matching report counts once within the group. Components mentioned later in the label or only in the narrative are not searched. How component counts work
Loaded 4 of 4 matching reports.
Open the full vehicle complaint log (all categories)TL*THE CONTACT OWNS A 2004 MERCURY MOUNTAINEER. WHILE DRIVING IN REVERSE AND SHIFTING GEARS, THE VEHICLE HESITATED. THE CRUISE CONTROL ENGAGED WITHOUT WARNING AND THE VEHICLE STALLED WHILE DRIVING 75MPH. THE SERVICE MANAGER DROVE WITH THE CONTACT AND OBSERVED THE FAILURE; HOWEVER, HE STATED THAT THE VEHICLE WAS OPERATING NORMALLY. THE ACCELERATOR ALSO DOES NOT ENGAGE PROPERLY WHEN INCREASING SPEED. THE DEALER STATED THAT THE ELECTRICAL BRAIN FAILED AND ATTEMPTED TO REPAIR IT ON TWO OCCASIONS. AN EXPERT FROM OUT OF STATE ALSO INSPECTED THE VEHICLE; HOWEVER, THEY WERE UNABLE TO DIAGNOSE THE FAILURE. WHILE APPROACHING A STOP SIGN, THE BRAKES FAILED AND ALMOST CAUSED A CRASH. THE DEALER STATED THAT THE MASTER CYLINDER FAILED. THE FAILURE MILEAGE WAS 5 AND THE CURRENT MILEAGE WAS 52,000.
BRAKE PEDAL RUBBER COVER CAME OFF DURING BRAKING. FOOT SLIPPED TO ACCELERATOR CAUSING CAR TO LEARCH FORWARD HITTING REAR OF PARKED CAR AND CAUSING DAMAGE TO THAT CAR. *JB
TL*- THE CONTACT STATED THAT WHILE DRIVING THE 2004 MERCURY MOUNTAINEER WITH 5000 FAILURE MILEAGE)AT 20 MPH AND TURNING AROUND IN A PARKING LOT THE VEHICLE SLOWED DOWN TO A COMPLETE STOP WITH THE FOOT ON THE BRAKE. THE VEHICLE WAS TURNED OFF AND RESTARTED. THE VEHICLE ONLY WENT APPROXIMATELY 100 YARDS. THE VEHICLE HAD TO BE TOWED TO THE DEALER, WHO HAD NOT DETERMINED THE CAUSE OF THE PROBLEM. THE CURRENT MILEAGE WAS 44,000. *AK
CONSUMER COMPLAINED ABOUT A BRAKE PROBLEM. WHEN APPLYING THE BRAKES PEDAL SANK IN INTERMITTENTLY. VEHICLE WAS TAKEN TO DEALER FOR SERVICE, BUT DEALER COULD NOT DUPLICATE THE PROBLEM. *AK
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
NHTSA source checks for this vehicle year
Checks are recorded separately for each dataset, not for the whole page. Dates use UTC. A missing check date does not mean no records exist.
Vehicle import recorded: Apr 28, 2026. This is the stored import date, not confirmation that every source was successfully refreshed.