Peterbilt 348 2017 - Page 177

OPERATINGTHEBRAKESYSTEM
tothehydraulicboosterintheevent
powersteeringuidstopsowing
throughtheboosterhead.
FrontandRearWheelCalipers:
translatehydraulicuidpressureinto
forceappliedateachwheel-endbrake
rotortoretardwheelmotion.
HydraulicBooster:Thehydraulic
boosterappliesadditionalhydraulic
forcefromthepowersteeringgearto
themastercylinderpistonwhenthe
brakepedalisapplied.
ParkingBrakeLamp:illuminates
whentheparkingbrakeisengaged
(theleverisintheupposition.)
ParkingBrakeLever:thehandlever
locatedinthecabwhichengagesor
disengagesthedrivelinedrumbrake.
PowerSteeringFlowSwitch:senses
owofpowersteeringuid.
PowerSteeringFluidReservoir:
storespowersteeringuidandoffersa
placetoreplenishwhenneeded.
PowerSteeringGear:assists
thesteeringoperationandsends
pressurizedpowersteeringuidtothe
brakebooster.
PowerSteeringPump:drawspower
steeringuidfromthereservoirand
sendsittothepowersteeringgear.
WarningBuzzer:soundswheneither
powersteeringuidowisinterrupted
orwhenapressuredifferentialis
presentbetweentheprimaryand
secondarybrakeuidpressure.
Eithercaseadverselyaffectsbraking
operation.
BrakeWarningLamp
Whenthebrakewarninglampcomes
on,itindicatesamalfunctioninthe
brakesystem.Possiblemalfunctions
includelossofhydraulicpressurefrom
thepowersteeringcircuitorapressure
differentialbetweentheprimaryand
secondarybrakecircuits.
WARNING!
Donotoperatethevehicleifthe
brakelightorbuzzercomeson.The
lightorbuzzerindicatesafailurein
oneofthebrakecomponents/sys-
tem.Driveyourvehicletotheside
oftheroadimmediately.Failureto
dothismayleadtoanaccidentand
severeinjury.
(03/17)Y53-6060-1C14-37
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