1981 Ford Bronco

ANALYSIS:ALLEGEDLY, DURING BRAKE APPLICATION THE DISC BRAKE CALIPERSSEIZE, RESULTING IN EXCESSIVE PULL AND/OR FRONT BRAKE LOCK-UP.SOMEREPORTS CITE A COMPLETE LOSS OF VEHICLE CONTROL RESULTING IN UNFOREWARNEDAND UNAVOIDABLE TRAVEL INTO OPPOSING TRAFFIC LANES.CONSUMERS CLAIM THATSERVICE PERSONNEL HAVE CONSISTENTLY ATTRIBUTED THE PROBLEM TO THE USE OFPHENOLIC PISTONS WHICH OVERHEAT AND SEIZE IN THE CALIPER BORES.INFORMATION PROVIDED BY THE MANUFACTURER DISCLOSED THE COMPLAINT, ACCIDENT,AND INJURY STATISTICS TABULATED ABOVE.OTHER MANUFACTURER-SUPPLIED DATADISCLOSED THAT TWO DESIGN CHANGES WITH POTENTIAL RELEVANCE TO THIS MATTERWERE MADE DURING THE PRODUCTION YEARS IN QUESTION.IN OCTOBER 1981, THESPECIFICATION OF THE MAXIMUM OUTSIDE DIAMETER OF THE PISTON WAS DECREASEDBY 0.0250 MM AND THE MINIMUM INSIDE DIAMETER OF THE CALIPER PISTON BOREINCREASED BY 0.024 MM.THESE CHANGES WERE MADE TO REDUCE THE POSSIBILITYOF PREMATURE WEAR OF THE FRONT DISC BRAKE PADS.A SECOND DESIGN REVISIONWAS MADE IN SEPTEMBER 1986 TO REDUCE INADVERTENT CHIPPING OF THE CALIPERPISTONS DURING BRAKE PAD REPLACEMENT.WARRANTY CLAIM DATA WERE INCONCLUS-IVE IN IDENTIFYING A FAILURE TREND ACCOMPANIED BY RISK OF ACCIDENTS.THE HISTORY OF BRONCO BRAKE PULL/DRIFT COMPLAINTS DISCLOSED THAT FORD HADKNOWLEDGE OF THE PROBLEM.AN AUGUST 1986, FORD TRUCK INTEROFFICE LETTERDISCUSSED THE PHENOMENON AND PROVIDED SUGGESTIONS TO REMEDY THE PROBLEMIN THE FIELD.THE CONDITION WAS DEFINED AS RECESSION STEER, MANIFEST TOTHE VEHICLE OPERATOR AS DRIFT OR PULL UPON BRAKE APPLICATION.IN FACT,THE SENSATION WAS ATTRIBUTED TO A NET STEER TO THE LEFT WHEN THE FRONTSUSPENSION MOVES REARWARD UNDER BRAKING FORCES.CONCLUSION:SEIZURE OF THE FRONT CALIPER PISTONS HAS NOT BEEN IDENTIFIEDAS THE ORIGIN OF THE ALLEGED PROBLEM.ADDITIONALLY, THE HISTORICAL DATAALLEGING LOSS OF VEHICLE CONTROL, ACCIDENTS, AND INJURIES DO NOT IDENTIFYA SAFETY-RELATED DEFECT IN EITHER THE BRAKING OR SUSPENSION SYSTEM OF THESUBJECT VEHICLES.======

TL* THE CONTACT OWNS A 1981 FORD BRONCO EQUIPPED WITH NEXEN TIRES, TIRE: LINE: NPRIZAH5 N/A, TIRE SIZE: 235/75R15 N/A, DOT NUMBER: 8EBN LMEL 4318. THE CONTACT STATED THAT HE PURCHASED FOUR NEW TIRES A YEAR AGO, AND STATED THAT WHILE HE WAS DRIVING AT 45 MPH, WITH HIS MECHANIC GOING ON TO THE INTERSTATE, THE CONTACT HEARD A LOUD BANG AND THE VEHICLE PULLED TO THE RIGHT AND COASTED TO THE SIDE OF THE ROAD AND NOTICED THE FRONT PASSENGER'S SIDE TIRE WAS FLAT. THE CONTACT STATED THAT WHILE HE AND HIS MECHANIC WERE REPLACING THE TIRE, THEY NOTICED THAT THE INSIDE OF THE TIRE WAS SLASHED. THE CONTACT REPLACED THE TIRE. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC WHERE THE CONTACT LEFT THE VEHICLE. THE CONTACT STATED THAT HE TOOK THE DAMAGED TIRE TO HIS RESIDENCE. THE CONTACT STATED THAT HE TAKEN THE TIRES BACK TO CRUZ TIRE SHOP WHERE HE PURCHASED THE TIRES BECAUSE THERE WAS A WARRANTY OF 50 MILES AND ONE YEAR OF ROAD HAZER AND WAS INFORMED THEY WOULD NOT REPLACE THE TIRES. THE CONTACT MENTIONED THAT THE TIRE SHOP WANTED TO PATCH THE TIRE. THE TIRE WAS NOT REPLACED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE VEHICLE FAILURE MILEAGE WAS 68,158 AND TIRE FAILURE MILEAGE WAS 500.

NHTSA ID

11348404

Incident

Aug 7, 2020

Mileage

68,158 mi

STEEL BELTS SEPARATED IN TWO PLACES: ONE CAUSED THE TREAD TO SHIFT OVER ABOUT 1 INCH; THE OTHER SEPARATION FOLDED UNDER ITSELF, AND CAUSED A KNOT THE WIDTH OF THE TREAD. *AK (DOT NUMBER: UNKK65A402 TIRESIZE: LT23575R15)

NHTSA ID

733975

Incident

Feb 22, 2000

INFORMATION REGARDING TRANSMISSION FLUID USAGE CHARTS. *SLC

FORD MOTOR COMPANY HAS RELEASED A NEW ELECTRICAL GREASE ( F8AZ - 19G208-AA ) TO REDUCE THE POSSIBILITY OF MOISTURE CORROSION AT THE TERMINALS. *YC

INFORMATION ON A NEW TRANSMISSION FLUID USAGE CHART. *YC

FLUID- TRANSMISSION FLUID USAGE CHARTS. *JD

FRAME- RIVET REPLACEMENT WITH BOLTS- SERVICE TIPS. *JD

NOISE- "POPPING/CREAKING"- FRONT FRAME OR SUSPENSION BRACKETS- FRAME- "POPPING/CREAKING"- FASTENER REPLACEMENT. *JD