ON CERTAIN TRUCKS, EQUIPPED WITH A FULL AIR BRAKE SYSTEM, THERE MAY BE 3 POSSIBLE DEFECTS RELATED TO THE PARKING BRAKE CHAMBER PORTION OF THE AIR BRAKE CHAMBER ASSEMBLY. THEY ARE AS FOLLOWS: (1) DUE TO IMPROPER INSTALLATION OF THE PARKING BRAKE CHAMBER END CAP DURING ASSEMBLY, WATER MAY ENTER THE PARKING BRAKE CHAMBER, CAUSING CORROSION OF THE POWER SPRING, LEADING TO POSSIBLE SPRING FAILURE. IN THE WORST CASE, RESULTANT DAMAGE COULD CAUSE THE PARKING BRAKE TO ENGAGE WHILE THE PARKING BRAKE LEVER IS IN THE RELEASED (OFF) POSITION. (2) DUE TO IMPROPER END CAP ATTACHING SCREW DIMENSIONS, WATER MAY ENTER THE PARKING BRAKE CHAMBER, CAUSING CORROSION OF THE POWER SPRING, LEADING TO POSSIBLE SPRING FAILURE. IN THE WORST CASE, RESULTANT DAMAGE COULD CAUSE THE PARKING BRAKE TO ENGAGE WHILE THE PARKING BRAKE LEVER IS IN THE RELEASED (OFF) POSITION. (3) DUE TO IMPROPER TIGHTENING OF THE END CAP ATTACHING SCREW DURING ASSEMBLY, WATER MAY ENTER INTO THE PARKING BRAKE CHAMBER, CAUSING CORROSION OF THE POWER SPRING, LEADING TO POSSIBLE SPRING FAILURE. IN THE WORST CASE, RESULTANT DAMAGE COULD CAUSE THE PARKING BRAKE TO ENGAGE WHILE THE PARKING BRAKE LEVER IS IN THE RELEASED (OFF) POSITION.