ON CERTAIN TRUCKS EQUIPPED WITH BENDIX SR-7 SPRING BRAKE MODULATING VALVES

Aug 15, 2007 — Recall Campaign #07V360000

ON CERTAIN TRUCKS EQUIPPED WITH BENDIX SR-7 SPRING BRAKE MODULATING VALVES, THE INTERNAL RUBBER CHECK VALVE MAY LEAK CAUSING A DELAY IN THE APPLICATION OF THE SPRING BRAKES TO PARK THE VEHICLE AFTER THE OPERATOR PULLS THE DASH VALVE BUTTON.

The recall was influenced by the manufacturer with about 18,805 units affected.

See recall notice

NHTSA Safety Recall Notice

07V360000

Manufacturer:	Mack Trucks, Inc.
Recall date:	August 15, 2007
NHTSA Campaign #:	07V360000
Units affected:	18,805

Description:: ON CERTAIN TRUCKS EQUIPPED WITH BENDIX SR-7 SPRING BRAKE MODULATING VALVES, THE INTERNAL RUBBER CHECK VALVE MAY LEAK CAUSING A DELAY IN THE APPLICATION OF THE SPRING BRAKES TO PARK THE VEHICLE AFTER THE OPERATOR PULLS THE DASH VALVE BUTTON.
Consequeces:: THIS COULD DELAY OR FAILURE IN APPLYING THE PARKING BRAKES WHICH COULD RESULT IN A VEHICLE ROLL AWAY, INCREASING THE RISK OF A CRASH.
Corrective action:: MACK IS WORKING WITH BENDIX TO REPAIR THESE VEHICLES (PLEASE SEE 07E037). BENDIX WILL INSTALL A CHECK VALVE REPAIR KIT FOR THE AFFECTED SR-7 SPRING BRAKE MODULATING VALVE FREE OF CHARGE. THE RECALL BEGAN ON JANUARY 10, 2008. OWNERS MAY CONTACT BENDIX AT 1-440-329-9000 OR MACK AT 1-800-528-6586.
Notes:: MACK RECALL NO. SC0335 (SC0328).CUSTOMERS MAY CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION'S VEHICLE SAFETY HOTLINE AT 1-888-327-4236 (TTY: 1-800-424-9153); OR GO TO HTTP://WWW.SAFERCAR.GOV.

Affects the following:

2007 MACK CHN Complaints
2007 MACK TRUCK CHN 613, 427 ASET AC ENGINE FAILURE DUE TO OIL PUMP DRIVE GEAR SPINNING LOOSE ON AUXILIARY SHAFT. WHEN THE VEHICLE BEGAN TRAVELING DOWN HILL, THE OIL PUMP DRIVE GEAR FAILED CAUSING AN IMMEDIATE LOSS OF OIL PRESSURE. THE ENGINE BECAME A CRITICAL INSTRUMENT IN CONTROLLING THE VEHICLE'S DOWN HILL SPEED PARTICULARLY THE ENGINE BRAKE FEATURE AKA THE "JAKE BRAKE". THE ENGINE BRAKE USES ENGINE OIL FLOW TO OPERATE. SINCE THERE WAS NO MORE OIL FLOW, THE ENGINE BRAKE WAS RENDERED UNUSABLE. AT THIS POINT, THE CHOICE WAS TO CONTINUE DOWN HILL AND RELY SOLELY ON THE VEHICLE BRAKES TO CONTROL THE VEHICLE SPEED, OR CONTINUE TO USE THE ENGINE WITHOUT THE ADDED BRAKING POWER OF THE ENGINE BRAKE KNOWING THAT THE ENGINE WOULD BE DESTROYED. THE DRIVER CHOSE TO DESTROY THE ENGINE AND NOT RISK HIS LIFE OR THE LIVES OF OTHERS. THE DEALER REFUSED TO REPAIR THE VEHICLE UNDER WARRANTY BECAUSE THE EECM INDICATED THE ENGINE'S MAXIMUM ALLOWED SPEED WAS EXCEEDED. FURTHER INVESTIGATION REVEALED THE PROBLEM IS INHERENT TO ALL ASET ENGINES BECAUSE THE OIL PUMP GEAR HELIX WAS CHANGED FOR THE NEW DESIGN ENGINE. THE AUXILIARY SHAFT DIRECTION OF ROTATION WAS REVERSED AND THE DIRECTION OF THRUST ON THE DRIVE GEAR FORCES THE DRIVE GEAR AWAY FROM THE REAR BEARING JOURNAL WHICH IT IS NESTED AGAINST. OLDER ENGINE DESIGN HAD THE DIRECTION OF THRUST TOWARD THE BEARING JOURNAL WHICH HELD THE GEAR IN PLACE. ANY CONDITION, (LIKE AN ENGINE OVERSPEED) THAT WOULD INCREASE OIL PRESSURE COULD DISLODGE THE GEAR. ACCORDING TO THE DEALER, AN ENGINE OVERSPEED CONDITION CAN ONLY OCCUR WHILE GOING DOWN HILL AND USING THE ENGINE TO CONTROL VEHICLE SPEED. IF THE HILL WOULD HAVE BEEN HIGHER, THE ENGINE MAY NOT HAVE BEEN ABLE TO CONTINUE TO SLOW THE VEHICLE AND A CRASH WOULD MOST LIKELY HAVE OCCURRED. THIS HAPPENED IN SOUTHEAST LOUISIANA WHERE HIGH HILLS ARE NON EXISTENT. HAD THIS HAPPENED IN A MOUNTAINOUS AREA, IT COULD HAVE BEEN DISASTROUS. MACK TRUCKS REFUSES TO DISCUSS THIS ANY FURTHER. *TR;