Troubleshooting Brake Systems - LA County Firefighters · March 2003March 2003 Fire Apparatus Driver/Operator 1AFire Apparatus Driver/Operator 1A Slide 2-12-3 Air Compressor With

Slide 2Slide 2--1212--11March 2003March 2003 Fire Apparatus Driver/Operator 1AFire Apparatus Driver/Operator 1A

Troubleshooting Brake Troubleshooting Brake SystemsSystems


RepairsRepairs

All repairs to brake All repairs to brake components should be components should be

conducted by aconducted by aqualified technicianqualified technician


Air Compressor With Air Compressor With GovernorGovernor

Excessive governor cutExcessive governor cut--in/cutin/cut--outoutPossible causePossible cause

Defective compressor and/or governorDefective compressor and/or governor

Possible corrective actionPossible corrective actionContact your department's fleet manager for a Contact your department's fleet manager for a plan of action plan of action


Air Compressor

Compressor Belt

Pressure Governor

Pressure Switch




Excessive system leakageExcessive system leakage

Possible corrective actionPossible corrective actionHave leak repairedHave leak repaired




Reservoir volume reducedReservoir volume reduced

Possible corrective actionPossible corrective actionDrain water from systemDrain water from system




Brakes out of adjustmentBrakes out of adjustment

Possible corrective actionPossible corrective actionContact your fleet managerContact your fleet manager



Passing excessive oil while draining tanksPassing excessive oil while draining tanksPossible causePossible cause

Poorly filtered airPoorly filtered air

Possible corrective actionPossible corrective actionCheck for defective intake componentsCheck for defective intake components



Passing excessive oil while draining tanksPassing excessive oil while draining tanksPossible causePossible cause

No air dryers in systemNo air dryers in system

Possible corrective actionPossible corrective actionDrain reservoirs dailyDrain reservoirs daily



Slow air buildupSlow air buildupPossible causePossible cause

Poorly filtered airPoorly filtered airExcessive governor cutExcessive governor cut--in/cutin/cut--outoutRestricted air dischargeRestricted air dischargeLoose pulleyLoose pulley





Air dryer purge valve stuck openAir dryer purge valve stuck open

Possible corrective actionPossible corrective actionHave air dryer purge valve repaired Have air dryer purge valve repaired Contact your fleet managerContact your fleet manager




Braided discharge line heat fatiguedBraided discharge line heat fatigued

Possible corrective actionPossible corrective actionCheck using a soap solutionCheck using a soap solution


General Brake SymptomsGeneral Brake Symptoms

Sensitive brakesSensitive brakesPossible causePossible cause

Brakes improperly adjustedBrakes improperly adjustedDefective or improperly installed componentDefective or improperly installed componentChamber/slack alignment binding Chamber/slack alignment binding momentarilymomentarilyFoot valve/pedal sticking Foot valve/pedal sticking LubricationLubricationInstallationInstallation




Brakes will not apply completelyBrakes will not apply completelyPossible causePossible cause

Brakes improperly adjustedBrakes improperly adjustedAutomatic slack adjuster malfunctionAutomatic slack adjuster malfunctionAir line or component freezeAir line or component freeze--upupFaulty brake componentsFaulty brake components\\Foot valve/pedal sticking or movement Foot valve/pedal sticking or movement restrictedrestricted



Brakes will not apply completelyBrakes will not apply completelyPossible causes (continued)Possible causes (continued)

Improper chamber/slack adjuster alignmentImproper chamber/slack adjuster alignmentNo air pressure in one brake circuitNo air pressure in one brake circuit




Brakes will not release completelyBrakes will not release completelyPossible causePossible cause

Parking brakes on; will not releaseParking brakes on; will not releaseBrakes improperly adjustedBrakes improperly adjustedCondition of brake componentsCondition of brake componentsAir lines pinched, improperly assembled, or Air lines pinched, improperly assembled, or misconnectedmisconnected



Brakes will not release completelyBrakes will not release completelyPossible cause (continued)Possible cause (continued)

System contaminationSystem contaminationChamber/slack adjuster bindingChamber/slack adjuster bindingAutomatic slack adjuster malfunctionAutomatic slack adjuster malfunction



Manual Slack AdjustersManual Slack Adjusters

Adjustment backs offAdjustment backs offPossible causePossible cause

Component malfunctionComponent malfunction



Locking Ring

Adjustment Nut


Automatic Slack AdjustersAutomatic Slack Adjusters

Refer to a Certified Refer to a Certified Air Brake TechAir Brake Tech

Automatic Slack Adjuster


Air System LeaksAir System Leaks

Air leak greater than 2 psi in one minuteAir leak greater than 2 psi in one minutePossible causePossible cause

Air leak when brakes are not appliedAir leak when brakes are not applied

Possible corrective actionPossible corrective actionStarting at the compressor, spray every fitting Starting at the compressor, spray every fitting with soapy waterwith soapy waterContact your fleet managerContact your fleet manager


Air System LeaksAir System Leaks

Air leak greater than 3 psi in one minuteAir leak greater than 3 psi in one minutePossible causePossible cause

Air leak in system when brakes are appliedAir leak in system when brakes are applied

Possible corrective actionPossible corrective actionSame as with 2 psi air leakSame as with 2 psi air leakHave someone assist youHave someone assist you


Hydraulic Brake SystemsHydraulic Brake Systems

Brake pedal feels soft and spongyBrake pedal feels soft and spongyPossible causePossible cause

Low amount of fluid in the systemLow amount of fluid in the system

Possible corrective actionPossible corrective actionAdd fluid to the reservoirAdd fluid to the reservoir



Brake pedal feels soft and spongyBrake pedal feels soft and spongyPossible causePossible cause

Air in the systemAir in the system

Possible corrective actionPossible corrective actionHave the air removed by a qualified Have the air removed by a qualified techniciantechnician



Pedal drifts toward or falls to the Pedal drifts toward or falls to the floorboardfloorboardPossible causePossible cause

Low amount of fluid in the systemLow amount of fluid in the system

Possible corrective actionPossible corrective actionAdd fluid to the reservoirAdd fluid to the reservoir



Pedal drifts toward or falls to the Pedal drifts toward or falls to the floorboardfloorboardPossible causePossible cause

Fluid leak in the systemFluid leak in the system

Possible corrective actionPossible corrective actionHave a qualified technician repair or replace Have a qualified technician repair or replace the source of the leak and restore the systemthe source of the leak and restore the system



Lack of response of a powered or vacuum Lack of response of a powered or vacuum assisted brake augmentation systemassisted brake augmentation systemPossible causePossible cause

Failure to transfer energy to the brake systemFailure to transfer energy to the brake system

Possible corrective actionPossible corrective actionHave a qualified technician restore the power Have a qualified technician restore the power assist systemassist system


Secondary Braking SystemsSecondary Braking Systems

Fails to activate as designedFails to activate as designedPossible causePossible cause

System is manually turned offSystem is manually turned off

Possible corrective actionPossible corrective actionEnsure the system is activated and is at the Ensure the system is activated and is at the proper stettingproper stetting


Secondary Braking SystemsSecondary Braking Systems

Fails to activate as designedFails to activate as designedPossible causePossible cause

System is activated but has failedSystem is activated but has failed

Possible corrective actionPossible corrective actionTake outTake out--ofof--serviceserviceHave a qualified technician repair the systemHave a qualified technician repair the system

Documents

Troubleshooting Brake Systems - LA County Firefighters · March 2003March 2003 Fire Apparatus Driver/Operator 1AFire Apparatus Driver/Operator 1A Slide 2-12-3 Air Compressor With