NHTSA Investigation EA99032

DUAL FUEL TANK CROSSFLOW/LEAKAGE

ON JULY 14, 1993 FORD FILED A DEFECT INFORMATION REPORT CONCERNING FUEL TANK CROSS FLOW LEAKAGE ON F-SERIES LIGHT TRUCKS AND CAB CHASSIS BUILT FROM JULY 22, 1989 THROUGH DECEMBER 17, 1992.THE REMEDY WAS TO REPLACE THE FUEL PRESSURE REGULATOR AND INSTALL A CHECK VALVE BETWEEN EACH FUEL SUPPLY LINE AND FUEL TANK (2) TO REPAIR THE SUPPLY SIDE FUEL CROSS FLOW PROBLEM (RECALL 93V-125).ODI OPENED RQ98-008 ON MAY 29, 1998 BECAUSE OF THE LARGE NUMBER OF ALLEGED REMEDY FAILURES AND REPORTS OF FUEL CROSS FLOW ON VEHICLES OUTSIDE OF THE RECALL POPULATION.BASED ONTHE INFORMATION RECEIVED FROM FORD ON AUGUST 11, SEPTEMBER 30, AND DECEMBER 15, 1998, AND THE INCREASING TREND OF REMEDY FAILURES AND OUT OF SCOPE CROSSFLOW REPORTS, ODI OPENED EA99-032 ON NOVEMBER 4, 1999.THE ATTACHED ENGINEERING ANALYSIS CLOSING REPORT FULLY DESCRIBES THE RESULTS OF THIS INVESTIGATION AND REASON FOR CLOSING.THE SUBJECT VEHICLES CAN EXPERIENCE FUEL TRANSFER FROM ONE TANK TO THE OTHER DUE TO MALFUNCTIONS IN THE FUEL SYSTEM.WHEN FUEL IS PUMPED OR RETURNED TO THE NON-OPERATING TANK (CROSS FLOW), THE CAPACITY OF THE NON-OPERATING TANK CAN BE EXCEEDED, CAUSING FUEL TO OVERFLOW PAST THE FILLER CAP, CREATING A FIRE POTENTIAL.

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.