2009 Suzuki 400 LTZ Quad Sport Service Manual, Page 361Get this manual
4A-5 Brake Control System and Diagnosis:
Diagnostic Information and Procedures
Brake Symptom Diagnosis
Condition Insufficient brake power Possible cause Leakage of brake fluid from hydraulic systemWorn pads or discOil adhesion on friction surface of padsWorn discAir in hydraulic systemNot enough brake fluid in the reservoirDefective adjustment of parking brakeCarbon adhesion on pad surfaceTilted padWorn pads and discForeign material in brake fluidClogged return port of master cylinderLoose front wheel axle or rear wheel axleAir in hydraulic systemInsufficient brake fluidImproper quality of brake fluidInsufficient tightening of connection jointsCracked hoseWorn piston andor cupWorn piston seal and dust sealRusty partInsufficient brake lever or brake pedal pivot lubricationImproper parking brake adjustmentB933H24104001
CorrectionReference Item Repair or replaceReplaceClean disc and padsReplaceBleed airReplenishAdjustRepair surface with sandpaperCorrect pad fitting or replaceReplaceReplace brake fluidDisassemble and clean master cylinderTighten to specified torqueBleed airReplenish fluid to specified level; bleed airReplace with correct fluidTighten to specified torqueReplaceReplace piston andor cupReplace piston seal and dust sealClean and lubricateLubricateAdjust