NHTSA Investigation PE87038

HYDROBOOST FAILURE

SUBJECT VEHICLES:CAPRICE, CAPRICE CLASSIC, CUSTOM CRUISER, DEVILLE,ELECTRA, ESTATE WAGON, FLEETWOOD, LESABRE, NINETY-EIGHT, PARISIENNE,PARK AVENUE.(ALL 1984-86 GM VEHICLES EQUIPPED WITH HYDROBOOST II SYSTEMS)ANALYSIS:CONSUMER COMPLAINTS ALLEGE SEVERAL PROBLEMS INVOLVING THE POWERSTEERING AND POWER BRAKE SYSTEMS OF THESE VEHICLES.THESE PROBLEMSINCLUDE: POWER STEERING FLUID LOSS, POWER BRAKE FLUID LOSS, LEAKAGE FROMTHE HYDRO-BOOST II POWER BRAKE BOOSTER, BROKEN BOOSTER SEALS, AND MASTERCYLINDER FAILURE.ALL PROBLEMS SEEM TO BE RELATED TO THE HYDRO-BOOST IIPOWER ASSIST SYSTEM, IN WHICH THE WORKING FLUID PROVIDES POWER ASSIST TO BOKE BOOSTER.THE EFFECT OF THESE PROBLEMS COULD BE A LOSS OF STEERINGCONTROL AND/OR BRAKE EFFECTIVENESS.STATUS:THE VOLUMINOUS AMOUNT OF DATA SUPPLIED BY GM IS PRESENTLY BEING CODED BY A CONTRACTOR AND SHOULD BE COMPLETED BY 12/30/87. GM DATA INDICATED A 50% WEIBULL DISTRIBUTION FAILURE AT 50K MILES FOR THE PISTON PUSH-ROD SEAL. THIS PE LOOKS TO HAVE AN EXTRODINARILY HIGH FREQUENCY, ALTHOUGH THE SEVERITY APEARS TO BE LOW.SHOULD BE INTERESTING DISCUSSING THIS FOR UPGRADE/CLOSURE.===

An investigation is a separate record from a recall and from a manufacturer communication. A manufacturer campaign to repair a safety defect or a failure to meet a federal safety standard.