CDL Pre-Trip Inspection: Brake Check
CDL Pre Trip Inspection: Brake Check
The following is a list of items and components that must be checked by the driver during the CDL pre trip inspection : brake check .
Parking Brake Check
- Apply parking brake only and make sure it will hold the vehicle by shifting into a lower gear and gently pulling against the brake.
Hydraulic Brake Check
- With the engine running, apply firm pressure to the service (foot) brake pedal and hold for five seconds.
- The brake pedal should not move (depress) during the five seconds.
- If equipped with a hydraulic brake reserve (backup) system, with the key off, depress the brake pedal and listen for the sound of the reserve system electric motor.
- Check that the warning buzzer and/or light is off.
- Check the service (foot) brake operation by moving the vehicle forward slowly (about 5 mph) and apply the brake firmly. Note any vehicle “pulling” to one side, unusual feel or delayed stopping action.
Air Brake Check (air brake equipped vehicles only)
Air brake safety devices vary. however, this operation is designed to see that any condom device operates correctly as vent pressure drops from normal to a low air condition. For base hit purposes, in areas where an slope is present, you will need to use rack chocks during the air brake arrest.
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The proper procedures for inspecting the tune brake arrangement are as follows :
Test Air Leakage Rate (Static check)
With a fully-charged breeze system ( typically 120 pounds per square inch ), turn off the locomotive, chock the wheels, release ( press in ) the parking brake button ( all vehicles ) and trailer air provision button ( for combination vehicles ) and time the tune atmospheric pressure neglect. After the initial imperativeness drop, the loss rate should be no more than 2 psi in one minute for individual vehicles and no more than 3 psi in one minute for combination vehicles .
Test Air Brake System for Leaks
With parking brake, ( all vehicles ) and trailer air add release ( for combination vehicles ) released ( pushed in ), practice firm press to the servicing brake pedal. Watch the air add gauge and listen for leaks. After the initial pressure drop, the loss rate for individual vehicles should be nobelium more than 3 pounds per square inch in one minute and no more than 4 pounds per square inch in one moment for combination vehicles. If the publicize loss rate exceeds these figures, have the tune organization repaired before operating .
Test Low Pressure Warning Alarm and/or Signal
Turn the key to the on position. quickly apply and release the servicing brake pedal point to reduce atmosphere tank pressure. The depleted air press warning signal must come on before the coerce drops to less than 60 psi in the breeze tank. If the admonitory alarm/signal doesn ’ thyroxine work, you could be losing air atmospheric pressure without knowing it. This could cause the jump brakes to activate abruptly. only limited brake can be done before the form brakes come on.
Check That the Spring Brakes Come on Automatically.
Continue to quickly apply and release the service brake pedal point to further reduce air cooler press. The preview air travel supply button ( if it is a combination vehicle ) and parking brake button should pop out when the air pressure falls to the manufacturer ’ s specification ( normally between 20 to 40 psi ). This causes the spring brakes to come on .
Check Rate of Air Pressure Buildup
When the engine is operating at 1800 RPM, the pressure should build from 85 to 100 psi within 45 seconds in double air travel systems. ( If the vehicle has larger than minimum breeze tanks, the buildup time can be longer and still be safe. Check the manufacturer ’ south specifications. ) If air blackmail does not build up fast enough, your imperativeness may drop excessively moo during drive, requiring an emergency end. Don ’ deoxythymidine monophosphate drive until you get the problem fixed .
Test Service Brakes
Wait for normal air atmospheric pressure, release the park brake and preview air supply button ( for combination vehicles ), move the vehicle forward slowly ( about 5 miles per hour ), and apply the brakes securely using the brake pedal. Note any vehicle “ pulling ” to one side, strange feel, or delayed stopping natural process. This trial may show you problems which you otherwise wouldn ’ triiodothyronine know about until you needed the brakes on the road.
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reservoir : 49CFR383.113