1999 GMC Sierra 1500 Pickup Owner's Manual - Page 404

Scheduled Maintenance Services Periodic Maintenance Inspections Listedbelowareinspectionsandserviceswhichshouldbeperformedatleast You shouldletyourGM twiceayear(forinstanceeachspringorfall). dealer's service department or other qualified service center do these jobs. Makesureanynecessaryrepairsarecompletedatonce. SteeringandSuspension lnspectiont -Inspect front and rear suspension andsteeringsystemfordamaged,looseormissingparts,signs ofwear or lack of lubrication.Inspectpowersteeringlinesandhosesforproperhook-up, binding,leaks,cracks,chafing,etc.(Onvehiclesequippedwithmanual steering gear,check forseal leakage.)Lubricatethesteeringlinkage. AcceleratorControlSystem -Lubricate allpivotpointswithengineoil, exceptthe TBI throttleshaft.Removeallexternaldepositsfromtheinjector Do this when theengine is cold pumpfacecamon6.2Land6.5Lengines. andnotrunning. Do not oil anyacceleratororcruisecontrolcables.Replace any cables that have high effortorexcessivewear. ExhaustSystemInspection -Inspect thecompletesystemincludingthe three-waycatalyticconverter.Inspectthebodyneartheexhaustsystem.Look forbroken,damaged,missingorout-of-positionparts,aswellas,open seams,holes,looseconnectionsorotherconditionswhichcouldcauseaheat buildup in thefloorpanor could letexhaustfumesseepintothepassenger compartments. DriveAxleService -Check readfrontaxle fluid levelandaddasneeded. Check constant velocity joints and axle seals for leaking. TransferCase(four-wheeldrive) lnspectiont -Every 12 monthsoratoil changeintervals,checkfrontaxleandtransfercaseandaddlubricantwhen necessary.Oilthecontrolleverpivotpointandallexposedcontrollinkage. Checkventhoseattransfercaseforkinksandproperinstallation.More frequentlubricationmayberequiredonheavy-duty or off-roaduse. t A fluid loss in thesesystemsmayindicateaproblem.Havetheminspected andrepairedatonce. 7-24