NHTSA Preliminary Evaluation PE08009

ODI'S INVESTIGATION OF THE SUBJECT POWER STEERING PUMP HAS FOUND THAT, WITH OVER FIVE YEARS OF OPERATIONAL EXPOSURE, THERE HAVE BEEN NO PUMP FAILURES THAT RESULTED IN LOSS OF POWER STEERING ASSIST WHILE THE VEHICLE WAS BEING DRIVEN ON THE ROAD OR ANY SUDDEN DROP OFF IN THE POWER STEERING ASSIST AT ANY TIME.THERE ARE NO CRASHES OR INJURIES.THESE REDUCTION IN ASSIST EVENTS HAVE ONLY OCCURRED DURING BACKING OR PARKING MANEUVERS.FREIGHTLINER AND TRW APPEAR TO HAVE ACTED RESPONSIBLY IN PROVIDING INFORMATION TO CUSTOMERS AND DEALERS REGARDING SAFE MAINTENANCE AND REPAIR PROCEDURES FOR POWER STEERING PUMPS THAT HAVE EXPERIENCED A REDUCTION IN SPEED OF STEER.FREIGHTLINER'S FIELD SERVICE BULLETIN, FSB 46-38, IS A DIAGNOSTIC PROCEDURE FOR DETERMINING IF THE TRW POWER STEERING PUMP IS RESPONSIBLE FOR REDUCED POWER ASSIST AND DESCRIBES CORRECTIVE ACTIONS THAT SHOULD BE TAKEN ONCE THE DETERMINATION IS MADE.THE CORRECTIVE ACTIONS ARE:REPLACE THE SPOOL VALVE ASSEMBLY (VEHICLES BUILT PRIOR TO 1/1/05) OR, REPLACE THE POWER STEERING PUMP (VEHICLES BUILT AFTER 1/1/05).A SAFETY-RELATED DEFECT TREND HAS NOT BEEN IDENTIFIED AT THIS TIME AND FURTHER USE OF AGENCY RESOURCES DOES NOT APPEAR TO BE WARRANTED.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT NO SAFETY-RELATED DEFECT EXISTS.THE AGENCY RESERVES THE RIGHT TO TAKE FURTHER ACTION IF WARRANTED BY THE CIRCUMSTANCES.FOR MORE DETAILED INFORMATION SEE DOCUMENT FILE.