Defect
THE TWO (2) RELAY SERVICE VALVES ARE CONNECTED TO THE SAME RESERVOIR RESULTING IN 4.25 TIMES, RATHER THAN 8 TIMES, THE COMBINED VOLUME OF ALL CHAMBERS AT MAXIMUM TRAVEL. THIS DOES NOT COMPLY WITH FMVSS 121, "AIR BRAKE SYSTEMS."
Consequence
REPEATED MAXIMUM BRAKE APPLICATIONS CAN RESULT IN THEACTIVATION OF THE LOW PRESSURE WARNING SYSTEM AS THE RESERVOIR IS DEPLETED ATHIGHER THAN SPECIFIED RATE.
Remedy
CHANGE ONE OF THE RELAY SERVICE VALVE SUPPLY LINES TO THE SECOND RESERVOIR.