Operation
•Thecommonruletofollowinusingtheengineand
transmission/rearaxletocontrolvehiclespeedisto
selectalowergeargoingdownthehillthanwouldbe
requiredtoascendthehill.Therearesomeexceptions,
suchasgoingdownashorthillwithgoodvisibilityand
nohazards.
•Theservicebrakesshouldbeusedtosupplement
availablevehicleretardationmethods.Whendescending
longgradesrequiringuseofthebrakes,shortapplications
(3-5secondsduration)shouldbemaderatherthanlong,
continuousapplications.Thisminimizestemperature
rise,brakefade,andairconsumptionofairbrakesystem.
AirBrakes
GeneralInformation
WARNING
Topreventpropertydamage,personalinjury,
and/ordeath,ifpartofthebrakesystemfails,
reducespeedandemploysafedrivingpractices
asstoppingdistancemayincreaseunderthe
failedconditionorifonlyonesectionofthebrake
systemisoperating.Havebrakesystemrepaired
immediately.Lossofbrakingcapabilitycould
causeanaccident.
Thetrucktypescoveredinthismanualareequippedwithasplit
brakesystem.
Thepurposeofthissplitsystemistoprovideameansof
stoppingthevehicleshouldafailureoccurineithertheprimary
orsecondarybrakesystem.Intheeventairpressureloss
occursinonesystem,theremainingsystemcontinuesto
providebrakingaction.
Whenafailureisdetectedtheairdryerisprovidedwithalimp
homefeaturetoallowthevehicletobedriventoaservicecenter.
Ifvehiclehasbeenparkedforanextendedperiodincold
weather,alwayschecktobesureallwheelsarerollingfree
(brakesarenotfrozen)whenstartingout.Alwaysclean
accumulatediceandsnowfrombrakelinkage.
AirGauge,LowAirPressureBeeperandWarningIndicator
WARNING
Topreventpropertydamage,personalinjury,
and/ordeath,neveroperatethevehiclewhen
insufcientairpressure(lessthan60psi[414
kPa])isindicatedforeithertheprimaryor
secondaryairsystem.Thevolumeofairrequired
tostopthevehiclemaybegreaterthanthat
available.Havethebrakesystemcheckedand
repairedbeforereturningthevehicletoservice.
Shouldairpressureineithersectionofthesplitairbrake
systembereducedto60-76psi(414-524kPa)thewarning
beeperwillsoundandtheredBRAKEPRESSUREwarning
indicatorontheinstrumentpanelwillglow.Also,theairgauge
/gaugeswillindicatelowairpressureinatleastoneofthe
independentsystems.ThewarningbeeperandREDindicator
willautomaticallyshutoffwhentheairpressureinbothsystems
issufcient(approximately55-76psi[379-524kPa])to
operatethevehicle.
183