NHTSA Engineering Analysis EA88001

SUMMARY OF INFORMATION FROM MANUFACTURER:CHRYSLER RECALLED, IN CANADA,67,602 1984 THROUGH 1987 PASSENGER CARS, TRUCKS, AND VANS EQUIPPED WITH THE5.2L ENGINE FOR INTERMITTENT LOSS OF BRAKE POWER ASSIST ON A SECONDAPPLICATION OF THE BRAKE PEDAL.THE DEFECT WAS A RESULT OF THE BRAKEBOOSTER VACUUM HOSE PORT IN THE BASE OF THE CARBURETOR BEING BLOCKED WITHFROZEN MOISTURE AFTER AN EXTENDED PERIOD OF HIGHWAY DRIVING AT LOW AMBIENTTEMPERATURES.TO PREVENT THIS DEFECT FROM OCCURRING, THE VACUUM SOURCE FORTHE BRAKE BOOSTER WAS RELOCATED FROM THE BASE OF THE CARBURETOR TO THEINTAKE MANIFOLD.IT WAS STATED THAT REPORTS OF THE ALLEGED DEFECT HAVEOCCURRED IN THE NORTHERN AREAS OF CANADA.ANALYSIS:REVIEW OF MANUFACTURER'S DATA INDICATED AT LEAST 4 SIMILAR U.S.VEHICLES HAVE EXPERIENCED FAILURES CONSISTENT WITH THOSE REPORTED IN THECANADIAN MARKET.ONE VEHICLE WAS A MANUFACTURER TEST VEHICLE.THE STATESIN WHICH THESE REPORTED FAILURES OCCURRED ARE ALASKA, MINNESOTA (2), ANDWISCONSIN.IT IS THIS ENGINEER'S OPINION THAT THERE IS SUFFICIENT EVIDENCETO SUGGEST THAT THE ALLEGED DEFECT COULD BE REPRODUCED BY PERFORMING TESTSIN A CONTROLLED ENVIRONMENTAL CHAMBER.STATUS:ANALYZING MANUFACTURER'S RESPONSE AT 12/09/87.===