LOW AIR WARNING PRESSURE SWITCH MAY NOT ACTIVATE THE WARNING SIGNAL UNTIL PRESSURE HAS DROPPED TO 55 PSI, RATHER THAN AT THE REQUIRED 60 PSI.
DRIVER WOULD NOT RECEIVE PROPER WARNING OF LOW AIR PRESSURE IN AIR BRAKE SYSTEM AND THIS CONDITION COULD RESULT IN A VEHICLE CRASH; ALSO, VEHICLE WOULD NOT COMPLY WITH FMVSS 121.
REPLACE INAPPROPRIATE AIR WARNING PRESSURE SWITCHES.