Investigations
REAR BRAKE LOCKUP
NHTSA Engineering Analysis EA84028 - closed, opened 1984-08-28.
NHTSA investigation EA84028 is a Engineering Analysis opened on 1984-08-28 and currently closed. The subject is tracked inside the Office of Defects Investigation queue. Latest activity on this investigation was logged on 1988-09-20 - NHTSA updates that field whenever an Information Request goes out, a supplement is filed, or a status change is recorded in the public docket.
An Engineering Analysis like EA84028 is the deeper technical phase that follows a PE. NHTSA requests design, warranty, and field-failure data from the manufacturer, conducts its own testing when needed, and determines whether the evidence supports a safety defect finding that would compel a recall.
Investigators summarized the matter as follows: "SUMMARY: CHEVETTE DIESELS HAVE THE SAME BRAKING SYSTEM AS GASOLINE ENGINEEQUIPPED CHEVETTES BUT CARRY MORE WEIGHT ON THE FRONT WHEELS. ALL 1983MODELS UTILIZE A DIFFERENT PROPORTIONING VALVE AND LARGER FRONT BRAKECALIPER..." Investigations are the early-warning layer of the federal auto-safety system, sitting upstream of formal recalls and defect orders. Whether this one closes without action or escalates into an Engineering Analysis, the full history stays in the ODI archive so researchers, litigators, and buyers can pull the paper trail at any time.
Investigation Summary
SUMMARY: CHEVETTE DIESELS HAVE THE SAME BRAKING SYSTEM AS GASOLINE ENGINEEQUIPPED CHEVETTES BUT CARRY MORE WEIGHT ON THE FRONT WHEELS. ALL 1983MODELS UTILIZE A DIFFERENT PROPORTIONING VALVE AND LARGER FRONT BRAKECALIPER PISTONS TO INCREASE FRONT BRAKE TORQUE. GM CLAIMS REAR BRAKEBIAS IS OF A MAGNITUDE WHICH DOES NOT CONSTITUTE A SAFETY DEFECT.ANALYSIS: TESTING AT ETF SHOWS THE SUBJECT VEHICLES HAVE SUBSTANTIALLYLESS THAN AVERAGE ADHESION UTILIZATION WHEN TESTED IN THE "AS RECEIVED"CONDITION BUT THEY PERFORMED WELL WHEN NEW, PROPERLY BURNISHED LININGSWERE INSTALLED. TESTS USING NEW BURNISHED LININGS DID NOT SUPPORT THECONSUMER COMPLAINT DATA OR DESIGN CHANGE THEORY, POSSIBLY DUE TO SMALLSAMPLE SIZE. (TESTING INDICATES THE SUBJECT VEHICLES ARE BETTER THANSOME GM "A" BODY GROUPS BUT WORSE THAN THE AVERAGE "A" BODY.GM IR RESPONSE DATED 5/15/87.STATUS: BRIEFING TO BE PREPARED.===
About This Investigation Type
An Engineering Analysis (EA) is the in-depth phase following a Preliminary Evaluation. NHTSA engineers conduct testing, collect data from manufacturers, and perform detailed technical analysis to determine whether a safety defect exists. An EA may lead to a voluntary recall by the manufacturer or, in rare cases, a mandatory recall order.
Data from NHTSA Office of Defects Investigation. Cross-references: NHTSA recall campaign API and NHTSA FARS where fatality records overlap. PlainCars does not rate or recommend vehicles. about how PlainCars sources NHTSA data.
Read our methodology - how this data is sourced, computed, and verified.