OPERATION283
Onvehiclesequippedwiththestandardtwovalvesystem,theoperationofonevalve
togetherwiththeotherpermitstheoperatortoselectthedesiredfunctionsdescribed
below:
RedValve(Trailer
AirSupply)
YellowValve(System
Park)
Function(Mode)
OutOut
SystemPark
In
Out
TrailerCharge
InIn
NormalRunning
Out
In
Bobtail
ParkingBrakeRelease
VNmodelshaveenginesequippedwithengineelectroniccontrolunits(EECU).
Thesehavetwofeaturesthatmayimpactthebrakesystem.Oneistheanti-stall
deviceintheEECUwhichsensestorquedemandandautomaticallycontrolsthe
enginetocompensateandmaintainspeed.Ontractorsequippedwithparkingbrakes
ononlyoneaxle,theanti-stalldevicekeepstheenginefromstalling,allowingthe
drivertopullawaywiththebrakesdragging.Thismayresultinoverheatedbrakes
anddamagedwheelhubs.
WARNING
Continualdraggingofthebrakeswill
causebrakestooverheat.Thismaylead
towheelendre.Toavoidoverheating,
makesurebothparkingbrakeknobsare
pushedinbeforedrivingoff.
Iftheyellowknobispulledoutandtheredknobispushedin,aconditioniscreated
wherethetrailerparkingbrakesarenotappliedandonlythesingledriveaxlebrakes
areapplied.Inthiscondition,thevehiclecanbedrivenaway.Therefore,itisvery
importantthatthedrivermakesuretheyellowANDredknobsarepushedinallthe
waybeforedrivingthevehicle.
Comments to this Manuals