Mack CSM 2010 - Automatic Slack Adjusters; Parking Brake System

118OPERATION
AutomaticSlackAdjusters
Automaticslackadjustersaredesignedtoautomaticallymaintainproperbrakechamber
pushrodtravelandcompensateforbrakeliningwearduringnormaluse.Manualadjustment
ofanautomaticslackadjustershouldneverbeperformedexceptwhenperformingbrake
orwheelservice(suchasbackingoffthebrakeshoesforwheelremoval,brakeshoe
relining/replacement,brakedrumreconditioning,etc.).
Whenpushrodtravelexceedsspecications(asgiveninthe"BRAKEADJUSTMENT"
sectionoftheMaintenanceandLubricationManual,)onavehicleequippedwithautomatic
slackadjusters,amechanicalproblemwiththeslackadjuster,brakecomponentsorimproper
installationoftheslackadjusterisindicated.Ifbrakesarefoundtobeoutofadjustment,the
vehiclemustbetakentothenearestrepairfacilityassoonaspossibletohavetheproblem
investigatedandcorrected.
DANGER
Automaticslackadjustersshouldnotbe
manuallyadjustedinanefforttocorrect
excessivepushrodstroke,becausethis
conditionindicatesthataproblemexists
withtheautomaticadjuster,withthe
installationoftheadjuster,orwithrelated
foundationbrakecomponents,which
manualadjustmentwillnotx.Manual
adjustmentofautomaticslackadjusters
isadangerouspracticethatcouldhave
seriousconsequences,becauseitgivesthe
operatorafalsesenseofsecurityabout
theeffectivenessofthebrakes,whichare
likelytogooutofadjustmentagainsoon.
ParkingBrakeSystem
Spring-typeparkingbrakesarestandardonallsingleandtandemrearaxles.
Thespringbrakesystemconsistsofanaircylinderwithheavysprings,whichisintegrated
withthespringbrakeairchamber.Whenthereisnopressureintheairchamber,thesprings
expand(causingabrakeapplication).Whenairpressureisappliedtotheairchamber,the
springsarecompressed(releasingthebrakes).