1993 GMC Suburban Owner's Manual - Page 298

rake Master Cylinder Yourbrakemastercylinder is here. It isfilledwith DOT-3 brakefluid. U2470 Thereareonlytworeasonswhythebrakefluidlevel in yourmastercylinder is thatthebrakefluidgoesdown to anacceptable mightgodown.Thefirst levelduringnormalbrakeliningwear.Whennewliningsareputin,thefluid level goesbackup.Theotherreasonisthatfluidisleakingoutofthebrake system. If it is,youshouldhaveyourbrakesystemfixed,since aleakmeans thatsoonerorlateryourbrakeswon'tworkwell,orwon'tworkatall. So, it isn't a good idea to "top off" yourbrakefluid.Addingbrakefluidwon'tcorrect aleak. If youaddfluidwhenyourliningsareworn,thenyou'llhavetoo muchfluidwhenyougetnewbrakelinings. You shouldadd(orremove) brakefluid, as necessaryonlywhenworkisdoneonthebrakehydraulic system. --. If you- avetoomuchbrakefluid, it canspillontheengine.Thefluid' will burn i he engine is hot enough. You or others could be burned, Add brakefluidonlywhen work andyourvehiclecouldbedamaged. isdone on thebrakehydraulicsystem. % RefertotheMaintenanceScheduletodeterminewhentocheckyourbrake fluid.See"PeriodicMaintenance" in theIndex. To Check Brake Fiuid: Youcancheckthebrakefluidwithouttaking off thecap.Just look atthe MlN windowsonthebrakefluidreservoir.Thefluidlevelsshouldbeabovethe mark. If theyaren't,haveyourbrakesystemcheckedtosee if there is a leak. 6-32