ON CERTAIN TRUCKS EQUIPPED WITH SR-7 BENDIX BRAKE VALVES, THE CHECK VALVE INSIDE THE VALVE CAVITY MAY

Jun 28, 2006 — Recall Campaign #06V232000

ON CERTAIN TRUCKS EQUIPPED WITH SR-7 BENDIX BRAKE VALVES, THE CHECK VALVE INSIDE THE VALVE CAVITY MAY NOT PROPERLY SET, CAUSING INTERNAL AIR LEAKAGE. IF THE CHECK VALVE DOES NOT PROPERLY SEAT, THE RESULTING LEAKAGE CAN CAUSE A DELAY IN THE APPLICATION OF THE SPRING BRAKES TO PARK THE VEHICLE AFTER OPERATOR PULLS THE DASH VALVE BUTTON.

The recall was influenced by the manufacturer with about 2,587 units affected.

See recall notice

NHTSA Safety Recall Notice

06V232000

Manufacturer:	Mack Trucks, Inc.
Recall date:	June 28, 2006
NHTSA Campaign #:	06V232000
Units affected:	2,587

Description:: ON CERTAIN TRUCKS EQUIPPED WITH SR-7 BENDIX BRAKE VALVES, THE CHECK VALVE INSIDE THE VALVE CAVITY MAY NOT PROPERLY SET, CAUSING INTERNAL AIR LEAKAGE. IF THE CHECK VALVE DOES NOT PROPERLY SEAT, THE RESULTING LEAKAGE CAN CAUSE A DELAY IN THE APPLICATION OF THE SPRING BRAKES TO PARK THE VEHICLE AFTER OPERATOR PULLS THE DASH VALVE BUTTON.
Consequeces:: THE DELAYED PARKING BRAKE APPLICATION CAN OCCUR WITHOUT WARNING, LEADING TO UNINTENDED VEHICLE ROLLAWAY INCREASING THE RISK OF A CRASH.
Corrective action:: DEALERS WILL INSPECT THE VALVES AND REPLACE IT FREE OF CHARGE. THE RECALL BEGAN ON AUGUST 14, 2006. OWNERS MAY CONTACT MACK TRUCKS AT 1-800-528-6586.
Notes:: MACK TRUCKS RECALL NO. SC0336 (SC0313).CUSTOMERS CAN ALSO 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;